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September 26th, 2021

Tech Tip: How to Determine a Barrel’s True Twist Rate

FirearmsID.com barrel rifling diagram
Erik Dahlberg illustration courtesy FireArmsID.com.

Sometimes you’ll get a barrel that doesn’t stabilize bullets the way you’d anticipate, based on the stated (or presumed) twist rate. A barrel might have 1:10″ stamped on the side but it is, in truth, a 1:10.5″ twist or even a 1:9.5″. Cut-rifled barrels, such as Kriegers and Bartleins, normally hold very true to the specified twist rate. With buttoned barrels, due to the nature of the rifling process, there’s a greater chance of a small variation in twist rate. And yes, factory barrels can be slightly out of spec as well.

After buying a new barrel, you should determine the true twist rate BEFORE you start load development. You don’t want to invest in a large supply of expensive bullets only to find that that won’t stabilize because your “8 twist” barrel is really a 1:8.5″. Sinclair International provides a simple procedure for determining the actual twist rate of your barrel.

Sinclair’s Simple Twist Rate Measurement Method
If are unsure of the twist rate of the barrel, you can measure it yourself in a couple of minutes. You need a good cleaning rod with a rotating handle and a jag with a fairly tight fitting patch. Utilize a rod guide if you are accessing the barrel through the breech or a muzzle guide if you are going to come in from the muzzle end. Make sure the rod rotates freely in the handle under load. Start the patch into the barrel for a few inches and then stop. Put a piece of tape at the back of the rod by the handle (like a flag) or mark the rod in some way. Measure how much of the rod is still protruding from the rod guide. You can either measure from the rod guide or muzzle guide back to the flag or to a spot on the handle. Next, continue to push the rod in until the mark or tape flag has made one complete revolution. Re-measure the amount of rod that is left sticking out of the barrel. Use the same reference marks as you did on the first measurement. Next, subtract this measurement from the first measurement. This number is the twist rate. For example, if the rod has 24 inches remaining at the start and 16 inches remain after making one revolution, you have 8 inches of travel, thus a 1:8″-twist barrel.

Determining Barrel Twist Rate Empirically
Twist rate is defined as the distance in inches of barrel that the rifling takes to make one complete revolution. An example would be a 1:10″ twist rate. A 1:10″ barrel has rifling that makes one complete revolution in 10 inches of barrel length. Rifle manufacturers usually publish twist rates for their standard rifle offerings and custom barrels are always ordered by caliber, contour, and twist rate. If you are having a custom barrel chambered you can ask the gunsmith to mark the barrel with the twist rate.

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September 5th, 2021

Beat the Heat — Cool Your Barrels with BarrelCool Device

BarrelCool fan battery cooling safety chamber indicator flag heat pump

The popular BarrelCool is a compact barrel-cooling device that also serves as an empty-chamber safety flag. A small, battery-powered fan drives cooling air through the barrel’s bore. Yes it really works — manufacturer-provided data shows that BarrelCool significantly reduces the time it takes to cool down a hot barrel. Look at the chart above to see what to expect.

In the past, folks have tried various methods to cool barrels: water flushed through the bore, CO2 tanks, even battery-operated fish pumps. BarrelCool is a simpler, less costly, and much handier solution. Priced at $39.99, this small device can definitely save you time at the range. Potentially it can save you money by extending barrel life. To see how Barrelcool works, watch th videos below that show the BarrelCool units in both bolt-action and AR-type rifles.

BarrelCool fan battery cooling safety chamber indicator flag heat pump

BarrelCool Range Reports from Forum Members
Forum members have been impress with the BarrelCool device. Member Comrade Terry said: “At the range, I spend a good bit of time waiting for the barrel to cool between shot strings. I fired my usual 50 rounds today, and (though it was 85° today) I was able to leave the range 30-40 minutes earlier than usual thanks to the BarrelCool. I like it!” Another Forum member, J-Rod, reports “Did some load development on my new rifle. This used to take forever due to the barrel heating up outside in full sun (90° ambient). I’d say this little gem cut about two hours off my normal shooting time. I got home early and the wife was happy — what’s that worth?”

How and Why BarrelCool Was Invented
BarrelCool originated from the idea that cease-fire periods would be a great time to cool a barrel. During cease-fires, most ranges and matches require empty chamber flags in the gun so that the range officer and everyone on the firing line can see visually that the gun is in a safe condition. The BarrelCool does double duty — cooling the barrel while serving as an empty-chamber indicator.

BarrelCool inventor Bryan Sumoba explains: “Previous barrel-cooling methods required additional steps such as running patches down the bore, or a fan that gets in the way of a required empty-chamber flag. BarrelCool now allows the shooter to cool the barrel while having the empty-chamber flag in the firearm.”

BarrelCool fan battery cooling safety chamber indicator flag heat pump

Sumoba says BarrelCool significantly shortens the time needed to cool down a hot barrel: “In controlled testing, it took about half the time to cool the barrel from 140 degrees F to 100 degrees F. Our customers also report significant reductions in the time it takes to cool down a hot barrel. At an F-Class match in Sacramento, one shooter fired 25 shots out of his 7mm RSAUM and got the barrel to the point where it was too hot to touch. We placed BarrelCool in his firearm and within 30 minutes, the barrel was back to near-ambient temperature.”

Using three (3) CR123A batteries, a BarrelCool unit can operate for 7-10+ hours. BarrelCool fits both AR-style rifles as well as most bolt action rifles. The Hi-Viz yellow color stands out on the firing line and BarrelCool is small enough to fit in most range or gun bags. Manufactured in the USA, Barrelcool can benefit competition, precision, or recreational shooters who need to cool down their barrels more rapidly, while displaying “safe condition” on the firing line. For more information, or to order for $34.99, visit www.barrelcool.com.

BATTERY TIP: We recommend rechargeable CR123A batteries for use in the BarrelCool. These can last many seasaons and can be charged at home or in a vehicle. Keep a spare set in your range bag. A 4-pack of C123A Lithium Batteries with USB recharger unit is $29.99 on Amazon

DukeDuke says:

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August 13th, 2021

Advanced Barrel Weight Calculator — Compare Lengths, Contours

Online Pac-Nor Barrel Calculator

pac-nor barrel weight contour calculatorCan you guess what your next barrel will weigh? In many competition disciplines, “making weight” is a serious concern when putting together a new match rifle. A Light Varmint short-range Benchrest rifle cannot exceed 10.5 pounds including scope. An F-TR rifle is limited to 18 pounds, 2 oz. (8.25 kg) with bipod.

One of the heaviest items on most rifles is the barrel. If your barrel comes in much heavier than expected, it can boost the overall weight of the gun significantly. Then you may have to resort to cutting the barrel, or worse yet, re-barreling, to make weight for your class. In some cases, you can remove material from the stock to save weight, but if that’s not practical, the barrel will need to go on a diet. (As a last resort, you can try fitting a lighter scope.)

Is there a reliable way to predict, in advance, how much a finished barrel will weigh? The answer is “yes”. PAC-NOR Barreling of Brookings, Oregon has created a handy, web-based Barrel Weight Calculator. Just log on to Pac-Nor’s website and the calculator is free to use. Pac-Nor’s Barrel Weight Calculator is pretty sophisticated, with separate data fields for Shank Diameter, Barrel Length, Bore Diameter — even length and number of flutes. Punch in your numbers, and the Barrel Weight Calculator then automatically generates the weight for 16 different “standard” contours.

pac-nor barrel weight contour calculator

Calculator Handles Custom Contours
What about custom contours? Well the Pac-Nor Barrel Weight Calculator can handle those as well. The program allows input of eight different dimensional measurements taken along the barrel’s finished length, from breech to muzzle. You can use this “custom contour” feature when calculating the weight of another manufacturer’s barrel that doesn’t match any of Pac-Nor’s “standard” contours.

Caution: Same-Name Contours from Different Makers May Not be Exactly the Same
One key thing to remember when using the Barrel Weight Calculator is that not all “standard” contours are exactly the same, as sold by different barrel-makers. A Medium Palma contour from Pac-Nor may be slightly different dimensionally from a Krieger Medium Palma barrel. When using the Pac-Nor Barrel Weight Calculator to find the weight of a barrel from a different manufacturer, we recommend you get the exact dimensions from your barrel-maker. If these are different that Pac-Nor’s default dimensions, use the “custom contour” calculator fields to enter the true dimensions for your brand of barrel.

Smart Advice — Give Yourself Some Leeway
While Pac-Nor’s Barrel Weight Calculator is very precise (because barrel steel is quite uniform by volume), you will see some small variances in finished weight based on the final chambering process. The length of the threaded section (tenon) will vary from one action type to another. In addition, the size and shape of the chamber can make a difference in barrel weight, even with two barrels of the same nominal caliber. Even the type of crown can make a slight difference in overall weight. This means that the barrel your smith puts on your gun may end up slightly heavier or lighter than the Pac-Nor calculation. That’s not a fault of the program — it’s simply because the program isn’t set up to account for chamber volume or tenon length.

What does this mean? In practical terms — you should give yourself some “wiggle room” in your planned rifle build. Unless you’re able to shave weight from your stock, do NOT spec your gun at one or two ounces under max based on the Pac-Nor calculator output. That said, the Pac-Nor Barrel Weight Calculator is still a very helpful, important tool. When laying out the specs for a rifle in any weight-restricted class, you should always “run the numbers” through a weight calculator such as the one provided by Pac-Nor. This can avoid costly and frustrating problems down the road.

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July 12th, 2021

Barrel End Threading — Bigger Diameter is Better

Barrel Threading AR15 ARX Robert Whitley bartlein

Our friend Robert Whitley of ARX Enterprises LLC has learned, through careful measurement and testing, that some barrels threaded 5/8″ x 24 TPI at the muzzle may not deliver optimal accuracy. The reason is that the end of the barrel can bell out slightly, like a trombone, because too much steel has been removed. This is particularly true with .30-caliber barrels, but it can also be a problem with smaller caliber barrels (even 6mm). Robert demonstrates this phenomenon in the video below. All gunsmiths, and anyone considering threading a barrel, should watch the video. At 1:00 – 1:30 Robert gauges a 5/8″ x 24-threaded .30-Caliber barrel. You can see the belling effect clear as day.

Barrel Threading AR15 ARX Robert Whitley bartlein

“When setting up a commercial barrel in the lathe, we noticed that the maximum-sized bushing that would fit in the bore at the chamber end was almost .0015” smaller [than what would fit] at the muzzle. That precipitated my pin-gauging of a number of different commercial barrels that were threaded for 5/8” x 24 tpi. What I found is what’s shown on the video.” – R. Whitley

Solve Problem with a Larger Thread Diameter
If 5/8″ x 24 threading is potentially harmful to accuracy, is there a solution? Yes, you simply need to leave a little more steel on the barrel. (See Video starting at 02:40.) Frank Green of Bartlein barrels states: “We get these questions all the time. I say run the largest thread diameter that is possible.” Robert Whitley has found that a 3/4″ x 28 TPI threading does not cause the “belling effect”. Accordingly Robert recommends 3/4″ x 28 if you need to thread your barrel for a muzzle brake or suppressor. Robert explains: “We only make 3/4” x 28 TPI muzzle brakes and that’s what we recommend to customers.”

Barrel Threading AR15 ARX Robert Whitley bartlein

“See how much meatier the 3/4″ threading is vs. the 5/8″. The 3/4″ threading offers a lot more metal around the bore. There’s a lot less opportunity for the bore to become bell-mouthed…” – Robert Whitley

Barrel Threading Diameter — What’s Important to Know

By Robert Whitley
In truth, the 5/8” x 24 TPI threading never came out of any accuracy-based think tank or set-up, it’s a military .30-Cal threading for barrels that someone has to carry around (they needed to keep the barrel weight down so it was smaller in diameter and the threading had to work with that situation). People have somehow assumed because the military uses that threading for certain things that it must mean that it’s also fine for a highly accurate rifle too, but that’s not really correct.

I don’t think there is any better and realistic option than the 3/4″ muzzle threading, and we also do it so there is no relief cut behind the threads on the barrel (i.e. put the relief cut on the brake or jam nut, don’t chop down on the muzzle of the barrel). For some reason many have a hard time grasping that the metal at the muzzle end of a rifle is “sacred” and you should not cut it down any more than absolutely necessary. A little threaded pencil diameter nub on the end of a barrel is not ideal for accuracy especially if it’s threaded and you need to torque on it. I cringe when I see a barrel with something like an MTU or Heavy Varmint contour, only to have an itty-bitty pencil thin threaded nub right at the muzzle so someone can “screw on a can” or a muzzle brake.

Lessons Learned Over the Years
A number of years ago I did a 30BR rifle project with Craig Kostyshyn who was big in the 30BR game and he made some of the best 30BR rifle barrels for benchrest competition. When I did the project I wanted a medium-heavy Palma type contour barrel I could use and also have a muzzle turndown for a front sight band. When he found out I was going to have the muzzle turned down he said “whoa, I need to provide for that when I make the barrel because if you turn the front down later you’ll be shooting a trombone” (i.e. the muzzle bore dimension would open up).

What he did was rough contour the barrel with the turndown (about .010” oversize) before he lapped the barrel, then when he lapped the barrel he took it easy in the muzzle area and worked the back of the barrel more. I thought he was a little bit excessive in his concerns but the barrel shot great and I wasn’t going to argue with him, after all he was shooting groups in the ones. I kind of just filed that away and never thought about it until recently when I went to have Fred from Sabreco do some chamber re-work on a commercial .30-caliber barrel I had. When setting up the barrel in the lathe and indicating things Fred noticed that the maximum-sized bushing that would fit in the bore at the chamber end was almost .0015” smaller [than what would fit] at the muzzle and he mentioned it to me. That precipitated my pin-gauging of a number of different commercial barrels I had that were threaded for 5/8” x 24 TPI. What I found is what’s shown on the video.

NOTE: This is a copyrighted article. Do not reproduce or re-link more than 75 words without written permission from AccurateShooter.com.

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July 11th, 2021

How Long Will Barrels Last? Dan Lilja Lists Factors to Consider

Lilja Rifle Barrels barrel life 3-groove AR15 Barrel heat

Barrel-maker Dan Lilja’s website, RifleBarrels.com has an excellent FAQ page that contains a wealth of useful information. On the Lilja FAQ Page you’ll find answers to many commonly-asked questions. For example, Dan’s FAQ addresses the question of barrel life. Dan looks at factors that affect barrel longevity, and provides some predictions for barrel life, based on caliber, chambering, and intended use.

NOTE: This article was very well-received when it was first published. We are reprising it for the benefit of readers who missed it the first time.

Dan cautions that “Predicting barrel life is a complicated, highly variable subject — there is not a simple answer. Signs of accurate barrel life on the wane are increased copper fouling, lengthened throat depth, and decreased accuracy.” Dan also notes that barrels can wear prematurely from heat: “Any fast varmint-type cartridge can burn out a barrel in just a few hundred rounds if those rounds are shot one after another without letting the barrel cool between groups.”

Q. What Barrel Life, in number of rounds fired, can I expect from my new barrel?

A: That is a good question, asked often by our customers. But again there is not a simple answer. In my opinion there are two distinct types of barrel life. Accurate barrel life is probably the type most of us are referencing when we ask the question. But there is also absolute barrel life too. That is the point where a barrel will no longer stabilize a bullet and accuracy is wild. The benchrest shooter and to a lesser extent other target shooters are looking at accurate barrel life only when asking this question. To a benchrest shooter firing in matches where group size is the only measure of precision, accuracy is everything. But to a score shooter firing at a target, or bull, that is larger than the potential group size of the rifle, it is less important. And to the varmint hunter shooting prairie dog-size animals, the difference between a .25 MOA rifle or one that has dropped in accuracy to .5 MOA may not be noticeable in the field.

The big enemy to barrel life is heat. A barrel looses most of its accuracy due to erosion of the throat area of the barrel. Although wear on the crown from cleaning can cause problems too. The throat erosion is accelerated by heat. Any fast varmint-type cartridge can burn out a barrel in just a few hundred rounds if those rounds are shot one after another without letting the barrel cool between groups. A cartridge burning less powder will last longer or increasing the bore size for a given powder volume helps too. For example a .243 Winchester and a .308 Winchester both are based on the same case but the .308 will last longer because it has a larger bore.

And stainless steel barrels will last longer than chrome-moly barrels. This is due to the ability of stainless steel to resist heat erosion better than the chrome-moly steel.

Barrel Life Guidelines by Caliber and Cartridge Type
As a very rough rule of thumb I would say that with cartridges of .222 Remington size you could expect an accurate barrel life of 3000-4000 rounds. And varmint-type accuracy should be quite a bit longer than this.

For medium-size cartridges, such as the .308 Winchester, 7×57 and even the 25-06, 2000-3000 rounds of accurate life is reasonable.

Hot .224 caliber-type cartridges will not do as well, and 1000-2500 rounds is to be expected.

Bigger magnum hunting-type rounds will shoot from 1500-3000 accurate rounds. But the bigger 30-378 Weatherby types won’t do as well, being closer to the 1500-round figure.

These numbers are based on the use of stainless steel barrels. For chrome-moly barrels I would reduce these by roughly 20%.

The .17 and .50 calibers are rules unto themselves and I’m pressed to predict a figure.

The best life can be expected from the 22 long rifle (.22 LR) barrels with 5000-10,000 accurate rounds to be expected. We have in our shop one our drop-in Anschutz barrels that has 200,000 rounds through it and the shooter, a competitive small-bore shooter reported that it had just quit shooting.

Remember that predicting barrel life is a complicated, highly variable subject. You are the best judge of this with your particular barrel. Signs of accurate barrel life on the wane are increased copper fouling, lengthened throat depth, and decreased accuracy.

Lilja Rifle Barrels barrel life 3-groove AR15 Barrel heat

Benchrest Barrel Life — You May Be Surprised
I thought it might be interesting to point out a few exceptional Aggregates that I’ve fired with 6PPC benchrest rifles with barrels that had thousands of rounds through them. I know benchrest shooters that would never fire barrels with over 1500 shots fired in them in registered benchrest matches.

I fired my smallest 100-yard 5-shot Aggregate ever in 1992 at a registered benchrest match in Lewiston, Idaho. It was a .1558″ aggregate fired in the Heavy Varmint class. And that barrel had about 2100 rounds through it at the time.

Lilja Rifle Barrels barrel life 3-groove AR15 Barrel heat

Another good aggregate was fired at the 1997 NBRSA Nationals in Phoenix, Arizona during the 200-yard Light Varmint event. I placed second at this yardage with a 6PPC barrel that had over 2700 rounds through it at the time. I retired this barrel after that match because it had started to copper-foul quite a bit. But accuracy was still good.

Lilja Rifle Barrels barrel life 3-groove AR15 Barrel heat

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May 16th, 2021

Don’t Kill Yourself — Bore Obstructions Cause Nasty Accidents

Obstructed Barrel Explosion Accident kaboom
Above is a sectioned barrel showing an 80gr Sierra that was fired in a .223 bolt action with a cleaning rod in the bore. Both the bullet and the rod are still in the bore.

A Negligent Shooter Gets Lucky
“Here we have a story so filled with negligent acts that I can only marvel that the shooter survived the experience. The photo and narrative were provided by the gunsmith who took in the repair job, my comments are in italics. It’s worth reading, we can’t get enough safety warnings in our hobby.” — GS Arizona, Rifleman’s Journal

Description of Incident (with Commentary)
The shooter had a stuck case in his .223 chamber. The stuck case was actually a loaded round that didn’t fire. It wouldn’t extract because it was a .222 case that got mixed in with his .223 brass. [He had loaded the wrong brass.] I saw the loaded round with an 80gr bullet in it and a light primer strike. Negligent Act #1: Wrong brass was mixed in with the brass being reloaded.

The shooter removed the stuck case with a 3-piece aluminum rod. Negligent Act #2: Hammering out a loaded round with a cleaning rod. People have been killed doing this as the round can fire and drive the cleaning rod right into you. I remember one such incident about 5 years ago, the shooter was pounding out a stuck round, the cleaning rod went right through him, he didn’t survive.

The shooter didn’t notice only two segments of the cleaning rod came out when he removed it. Negligent Act #3: If you put anything at all down the barrel of a rifle you’d better make darn sure you got it all out before doing anything else!

He then chambered another round and fired it. Negligent act #4: If you’ve had a barrel obstruction of any kind, and if you’ve put something in the barrel, look through the barrel before proceeding! Within the past two years I know of an incident in which a benchrest shooter was killed in exactly this manner. The pressure built up and the rifle bolt came out of the receiver and into his chest.

The shooter is ‘OK’, but did not escape unscathed. He said there was a huge explosion and after regaining his senses found he was bleeding heavily from his forehead. The blood was thick enough that it ran in his eyes and he couldn’t see. In his words “I thought I was going to die”.

He has what looks like a pretty deep cut about an inch long on the side of his head, right in line with his right eye starting where the eye socket turns out to the side of the skull. And no telling what he’s got in the way of brass particles embedded in his forehead.

He was shooting on private property, and was alone when this happened. Negligent Act #5: Don’t shoot alone! Accidents happen, this is just one more example. If we could predict accidents, we wouldn’t have them. Always shoot with at least one other person.

He managed to get the bleeding stopped, or at least under control, packed his car and drove himself home without seeking immediate medical attention. Negligent Act #6: This one could have cost him his life after being lucky enough to survive the incident. There’s no way to know what’s happened just after an incident like this. He should have been at a hospital getting checked for shrapnel in the head.

The rod and slug could not be driven out. Since the barrel had a high round count there was no point in trying to salvage it. Note that the aluminum rod is expanded to a tight fit in the bore for the first couple inches. The base of the bullet is a little over 2″ from the mouth of the chamber.

What we’ve seen here is negligence and an absolute indifference to the established rules of safe reloading and gun handling, from start to finish, capped off with the shooter’s foolish avoidance of medical treatment. This shooter is lucky to be alive, but he’s surely used up all his luck. Don’t assume you’ll be so fortunate.

This article originally appeared in the Rifleman’s Journal website, which is no longer available.

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October 21st, 2020

Brownells Video Shows How to Cut Chamfer on Barrel Crown

brownells crown muzzle barrel bullet accuracy gunsmithing

This video from Brownells talks about a the crown of a barrel and how the crown’s condition affects accuracy. As the bullet leaves the barrel of the gun, the shape, alignment and the condition of the crown can affect the accuracy of your shot. A proper crown is essential to ensure that the bullet leaves the barrel correctly and that the propellant gasses behind the bullet are distributed evenly on firing. A square crown without burrs and a smooth transition will normally ensure consistency from shot to shot. By contrast, a damaged crown can cause unpredictable flyers that open your group. That’s why it’s important to have perfect crowns on all your barrels.

The video explains the different types of crowns that can be used. In addition, the video shows how you can chamfer your muzzle in a home shop. If you use a properly-sized pilot, cutting a shallow chamfer is something that most guys with some mechanical skill can handle. Just be sure to use lubricant, flush chips, and don’t rush the job. Cutting the barrel is another matter. At the 1:20 mark the video shows how to use a hack-saw to remove a damaged muzzle section. While this may be fine for an inexpensive rifle that needs a “quick fix”, we do NOT recommend using a hack-saw with a vise for a competition barrel. The reason is that it is too easy for a novice to produce a cut that is not square. We suggest letting a professional gunsmith cut and crown your competition barrels.

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June 11th, 2020

Smart Advice on Shipping Gun Parts and Firearms Accessories

Shipping information news Fedex UPS USPS postal service

shipping gun parts UPS FEDEXGun guys are always shipping stuff around the country — whether it’s a barrel to be chambered, or a scope that needs to go back for warranty repair. Or maybe you’ve sold some bullets or reloading dies you no longer need. To ensure your precious packages get to their destination in one piece, it’s important to take precautions when boxing up your items. And by all means insure packages for full value — even if your packaging is perfect, there is always the possibility that your shipment might be lost altogether. Sadly, that can happen, no matter which carrier you choose: Fedex, UPS, or the U.S. Postal Service (USPS). Here are some tips for shipping gun stuff — we explain how to pack items properly and how to minimize the risk of loss.

Tips for Shippers
Dennis Haffner from McGowen Precision Barrels offers some advice on how to avoid damage when shipping gun parts or other valuable or heavy items. Dennis explains:

shipping gun parts UPS FEDEX“First, I started double-packing the contents and in many cases double-boxing. I spend a fortune on heavy-reinforced shipping tape. If the contents are loosely packed, the package is going to get crushed. On real important items or delicate items, wrap the content in plastic and spray the inside void areas with non-expanding foam. They make shipping foam just for this. This method really works. Since I started paying more attention to packaging, I have just about wiped out my issues with all three companies (Fedex, UPS, USPS). Yes, I hate doing it, but in the long run for us, it’s cheaper.

Bullet shipments are the worst — a shipment of 500+ bullets can destroy a cardboard box. I have ordered bullets from individuals who put them in baggies and filled the remainder of the box with foam peanuts. That is not going to work. Any piece of metal, including a die, will puncture a cardboard box, or destroy a padded envelope. Just look at the tracking information and imagine your package bouncing around in the back of the shipping truck, probably under many other packages. My advice is to NEVER use padded envelopes. Barrel nuts or recoil lugs will most likely never make it.

ORM-D items are required to be shipped in heavily-reinforced, double-walled containers. The packages still get a little damage, but the contents usually survive.

shipping gun parts UPS FEDEXHow do shipments get damaged? Consider this — one of the shipping companies this year flipped (overturned) one of our new CNC machines (which rendered it useless). Maybe your small packages were in the same delivery truck as my CNC machine. I wonder how many little boxes were crushed underneath it.

As for USPS flat rate boxes — you would not believe what people try to stuff in these boxes. USPS finally put a weight limit on the boxes — they had to. I sometimes take my delicate items packed in an envelope or small box. I spray foam in a larger flat rate box and insert the smaller package, then fill the remainder of the void with foam. It works, and part usually arrives undamaged.”

shipping gun parts UPS FEDEX
Shipping Rifle Barrels (PVC Tube and Tennis Ball Method)
A new match-grade barrel can cost $350 or more, and it might take six months (or more) to replace it, given the current wait time with top barrel-makers. So, you don’t want your nice new tube to get damaged in transit. Forum Member Chuck L. (aka “M-61″) offers these tips for shipping rifle barrels:

shipping gun parts UPS FEDEX“Packing a barrel can be a problem. Here’s a shipping method that won’t stop lost shipments but so far has stopped damage. Get a PVC pipe (of size appropriate to your barrel) with fitted caps for each end. Attach a cap to one end. Tape the barrel threads and tape over the muzzle. Then drop one standard tennis ball into the pipe. Place barrel in pipe. Next add whatever peanuts or foam you can jam in to support the barrel on the sides. Then place a second tennis ball into the opposite end of the PVC pipe. (So now you have a tennis ball on either end of your barrel.) With everything secure inside, attach the upper cap and tape it down securely. With this packing procedure, when the carrier launches the pipe like a javelin, at least the barrel will not come through like a spear and be gone. Label the pipe with very large address labels so no one suspects it’s just garbage laying around. This procedure may seem ridiculous but it has worked for me. Oh and definitely get insurance. If your item is insured, the shippers will look harder to find it.”

Editor’s Note: Fedex also makes a triangular-profile cardboard shipping box. This 38″ x 6″ x 6″ x 6″ Fedex Tube (designed for blueprints and posters) is free for the asking. For most barrels, there should be enough clearance to hold your PVC tube (with barrel packed inside tube). However, don’t ship the barrel inside the cardboard box by itself. Cap and pad the ends and bubble wrap it heavily, or better yet, use the PVC tube method described above, with the PVC tube inside the box.

For More Packing and Shipping Advice, Read this Forum Thread.

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January 30th, 2020

Can You Predict Useful Barrel Life? Insights from Dan Lilja

Lilja Rifle Barrels barrel life 3-groove AR15 Barrel heat

Barrel-maker Dan Lilja’s website has an excellent FAQ page that contains a wealth of useful information. On the Lilja FAQ Page as you’ll find informed answers to many commonly-asked questions. For example, Dan’s FAQ addresses the question of barrel life. Dan looks at factors that affect barrel longevity, and provides some predictions for barrel life, based on caliber, chambering, and intended use.

NOTE: This article was very well-received when it was first published last year. We are reprising it for the benefit of readers who missed it the first time.

Dan cautions that “Predicting barrel life is a complicated, highly variable subject — there is not a simple answer. Signs of accurate barrel life on the wane are increased copper fouling, lengthened throat depth, and decreased accuracy.” Dan also notes that barrels can wear prematurely from heat: “Any fast varmint-type cartridge can burn out a barrel in just a few hundred rounds if those rounds are shot one after another without letting the barrel cool between groups.”

Q. What Barrel Life, in number of rounds fired, can I expect from my new barrel?

A: That is a good question, asked often by our customers. But again there is not a simple answer. In my opinion there are two distinct types of barrel life. Accurate barrel life is probably the type most of us are referencing when we ask the question. But there is also absolute barrel life too. That is the point where a barrel will no longer stabilize a bullet and accuracy is wild. The benchrest shooter and to a lesser extent other target shooters are looking at accurate barrel life only when asking this question. To a benchrest shooter firing in matches where group size is the only measure of precision, accuracy is everything. But to a score shooter firing at a target, or bull, that is larger than the potential group size of the rifle, it is less important. And to the varmint hunter shooting prairie dog-size animals, the difference between a .25 MOA rifle or one that has dropped in accuracy to .5 MOA may not be noticeable in the field.

The big enemy to barrel life is heat. A barrel looses most of its accuracy due to erosion of the throat area of the barrel. Although wear on the crown from cleaning can cause problems too. The throat erosion is accelerated by heat. Any fast varmint-type cartridge can burn out a barrel in just a few hundred rounds if those rounds are shot one after another without letting the barrel cool between groups. A cartridge burning less powder will last longer or increasing the bore size for a given powder volume helps too. For example a .243 Winchester and a .308 Winchester both are based on the same case but the .308 will last longer because it has a larger bore.

And stainless steel barrels will last longer than chrome-moly barrels. This is due to the ability of stainless steel to resist heat erosion better than the chrome-moly steel.

Barrel Life Guidelines by Caliber and Cartridge Type
As a very rough rule of thumb I would say that with cartridges of .222 Remington size you could expect an accurate barrel life of 3000-4000 rounds. And varmint-type accuracy should be quite a bit longer than this.

For medium-size cartridges, such as the .308 Winchester, 7×57 and even the 25-06, 2000-3000 rounds of accurate life is reasonable.

Hot .224 caliber-type cartridges will not do as well, and 1000-2500 rounds is to be expected.

Bigger magnum hunting-type rounds will shoot from 1500-3000 accurate rounds. But the bigger 30-378 Weatherby types won’t do as well, being closer to the 1500-round figure.

These numbers are based on the use of stainless steel barrels. For chrome-moly barrels I would reduce these by roughly 20%.

The .17 and .50 calibers are rules unto themselves and I’m pressed to predict a figure.

The best life can be expected from the 22 long rifle (.22 LR) barrels with 5000-10,000 accurate rounds to be expected. We have in our shop one our drop-in Anschutz barrels that has 200,000 rounds through it and the shooter, a competitive small-bore shooter reported that it had just quit shooting.

Remember that predicting barrel life is a complicated, highly variable subject. You are the best judge of this with your particular barrel. Signs of accurate barrel life on the wane are increased copper fouling, lengthened throat depth, and decreased accuracy.

Lilja Rifle Barrels barrel life 3-groove AR15 Barrel heat

Benchrest Barrel Life — You May Be Surprised
I thought it might be interesting to point out a few exceptional Aggregates that I’ve fired with 6PPC benchrest rifles with barrels that had thousands of rounds through them. I know benchrest shooters that would never fire barrels with over 1500 shots fired in them in registered benchrest matches.

I fired my smallest 100-yard 5-shot Aggregate ever in 1992 at a registered benchrest match in Lewiston, Idaho. It was a .1558″ aggregate fired in the Heavy Varmint class. And that barrel had about 2100 rounds through it at the time.

Lilja Rifle Barrels barrel life 3-groove AR15 Barrel heat

Another good aggregate was fired at the 1997 NBRSA Nationals in Phoenix, Arizona during the 200-yard Light Varmint event. I placed second at this yardage with a 6PPC barrel that had over 2700 rounds through it at the time. I retired this barrel after that match because it had started to copper-foul quite a bit. But accuracy was still good.

Lilja Rifle Barrels barrel life 3-groove AR15 Barrel heat

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January 29th, 2020

The Dummy Round — Why You Need One for Chambering

Gre Tannel GreTan, Gre-Tan Rifles dummy round chambering gunsmith reamer chamber

How and Why to Create a Dummy Round
When you have a new custom rifle built, or a new barrel fitted to an existing rifle, it makes sense to create a dummy round. This should have your preferred brass and bullet types, with the bullet positioned at optimal seating depth. A proper dummy round helps the gunsmith set the freebore correctly for your cartridge, and also ensure the proper chamber dimensions.

Respected machinist, tool-maker, and gunsmith Greg Tannel of Gre-Tan Rifles explains: “I use the dummy round as a gauge to finish cut the neck diameter and throat length and diameter so you have [optimal] clearance on the loaded neck and the ogive of the bullet just touches the rifling.” He recommends setting bullet so the full diameter is just forward of the case’s neck-shoulder junction. “From there”, Greg says, “I can build you the chamber you want… with all the proper clearances”.

Greg Tannel has created a very helpful video showing how to create a dummy round. Greg explains how to measure and assemble the dummy and how it will be used during the barrel chambering process. Greg notes — the dummy round should have NO Primer and No powder. We strongly recommend that every rifle shooter watch this video. Even if you won’t need a new barrel any time soon, you can learn important things about freebore, leade, and chamber geometry.

This has been a very popular video, with 244,000 views. Here are actual YouTube comments:

That is the best explanation I’ve ever seen. Thank you sir. — P. Pablo

Nice video. You do a very good job of making this easy for new reloaders to understand. I sure wish things like this were available when I started reloading and having custom rifles built. Once again, great job, and your work speaks for itself. — Brandon K.

Beautiful job explaining chambering clearances. — D. Giorgi

Another Cool Tool — The Stub Gauge

When you have your gunsmith chamber your barrel, you can also have him create a Stub Gauge, i.e. a cast-off barrel section chambered like your actual barrel. The stub gauge lets you measure the original length to lands and freebore when your barrel was new. This gives you a baseline to accurately assess how far your throat erodes with use. Of course, as the throat wears, to get true length-to-lands dimension, you need take your measurement using your actual barrel. The barrel stub gauge helps you set the initial bullet seating depth. Seating depth is then adjusted accordingly, based on observed throat erosion, or your preferred seating depth.

Stub Gauge Gunsmithing chamber gage model barrel

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July 2nd, 2019

Figure Out Exact Barrel Weight with Pac-Nor Calculator

Online Pac-Nor Barrel Calculator

Can you guess what your next barrel will weigh? In many competition disciplines, “making weight” is a serious concern when putting together a new match rifle. A Light Varmint short-range Benchrest rifle cannot exceed 10.5 pounds including scope. An F-TR rifle is limited to 18 pounds, 2 oz. (8.25 kg) with bipod.

One of the heaviest items on most rifles is the barrel. If your barrel comes in much heavier than expected, it can boost the overall weight of the gun significantly. Then you may have to resort to cutting the barrel, or worse yet, re-barreling, to make weight for your class. In some cases, you can remove material from the stock to save weight, but if that’s not practical, the barrel will need to go on a diet. (As a last resort, you can try fitting a lighter scope.)

Is there a reliable way to predict, in advance, how much a finished barrel will weigh? The answer is “yes”. PAC-NOR Barreling of Brookings, Oregon has created a handy, web-based Barrel Weight Calculator. Just log on to Pac-Nor’s website and the calculator is free to use. Pac-Nor’s Barrel Weight Calculator is pretty sophisticated, with separate data fields for Shank Diameter, Barrel Length, Bore Diameter — even length and number of flutes. Punch in your numbers, and the Barrel Weight Calculator then automatically generates the weight for 16 different “standard” contours.

Calculator Handles Custom Contours
What about custom contours? Well the Pac-Nor Barrel Weight Calculator can handle those as well. The program allows input of eight different dimensional measurements taken along the barrel’s finished length, from breech to muzzle. You can use this “custom contour” feature when calculating the weight of another manufacturer’s barrel that doesn’t match any of Pac-Nor’s “standard” contours.

Caution: Same-Name Contours from Different Makers May Not be Exactly the Same
One final thing to remember when using the Barrel Weight Calculator is that not all “standard” contours are exactly the same, as produced by different barrel-makers. A Medium Palma contour from Pac-Nor may be slightly different dimensionally from a Krieger Medium Palma barrel. When using the Pac-Nor Barrel Weight Calculator to “spec out” the weight of a barrel from a different manufacturer, we recommend you get the exact dimensions from your barrel-maker. If these are different that Pac-Nor’s default dimensions, use the “custom contour” calculator fields to enter the true specs for your brand of barrel.

Smart Advice — Give Yourself Some Leeway
While Pac-Nor’s Barrel Weight Calculator is very precise (because barrel steel is quite uniform by volume), you will see some small variances in finished weight based on the final chambering process. The length of the threaded section (tenon) will vary from one action type to another. In addition, the size and shape of the chamber can make a difference in barrel weight, even with two barrels of the same nominal caliber. Even the type of crown can make a slight difference in overall weight. This means that the barrel your smith puts on your gun may end up slightly heavier or lighter than the Pac-Nor calculation. That’s not a fault of the program — it’s simply because the program isn’t set up to account for chamber volume or tenon length.

What does this mean? In practical terms — you should give yourself some “wiggle room” in your planned rifle build. Unless you’re able to shave weight from your stock, do NOT spec your gun at one or two ounces under max based on the Pac-Nor calculator output. That said, the Pac-Nor Barrel Weight Calculator is still a very helpful, important tool. When laying out the specs for a rifle in any weight-restricted class, you should always “run the numbers” through a weight calculator such as the one provided by Pac-Nor. This can avoid costly and frustrating problems down the road.

Credit Edlongrange for finding the Pac-Nor Calculator
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June 25th, 2019

Monitor Summer Barrel Heat with Handy Temp Strips

Barrel Heat Temp Temperature gauge strip McMaster Carr

You never want your barrels to get too hot, which can happen more quickly in summertime. Accuracy suffers when barrels over-heat, and excessive heat is not good for barrel life. So how do you monitor your barrel’s temperature? You can check if the barrel is “warm to the touch” — but that method is not particularly precise. There is a better way — using temperature-sensitive strips. McMaster.com (an industrial supply house) offers stick-on temp strips with values from 86° F to 140° F. A pack of ten (10) of these strips (item 59535K13) costs $12.16 — so figure it’ll cost you about $1.20 per barrel for strips. That’s cheap insurance for your precious barrels. For best barrel life, try to stay under 120 degrees F.

Barrel Heat Temp Temperature gauge strip McMaster Carr

Forum member Nomad47 says: “I have temperature strips (bought at McMaster-Carr) on all my barrels. I try not to shoot when the barrel gets to 122 degrees or higher[.]” Here are photos of the McMaster-Carr temp strips on Nomad47’s customized Savage.

Barrel Heat Temp Temperature gauge strip McMaster Carr

Bad things can happen if your barrel gets too hot. First, with some barrels, the point of impact (POI) will shift or “walk” as the barrel heats up excessively. Second, even if the POI doesn’t change, the groups can open up dramatically when the barrel gets too hot. Third, if the barrel is very hot, the chamber will transfer heat to your loaded cartridge, which can lead to pressure issues. Finally, there’s considerable evidence that hot barrels wear out faster. This is a very real concern, particularly for varmint shooters who may shoot hundreds of rounds in a day. For this reason, many varminters switch among various guns, never letting a particular barrel get too hot.

Neconos.com offers Bar-L Temp Strips that visually display heat readings from 86 to 140 degrees. Think of these strips as compact, unbreakable thermometers. With adhesive backing, they can also be used to monitor barrel heating. Put a strip on the side of the barrel and the barrel’s temp will be indicated by a stripe that changes from black to green. There is also a “general purpose” strip that reads to 196 degrees (bottom row). The Benchrest strip (86F to 140F) is in the middle. Bar-L temp strips cost $9.00, or $25.00 for a 3-pack.

Permalink Gear Review, Tech Tip 4 Comments »
December 12th, 2018

Tuning Barrels for Enhanced Precision and Accuracy

Anschutz Tuner

When a shot is fired through it, a barrel will exhibit harmonics. Tuning these harmonics (the “waves” that propagate through the barrel) can alter point of impact and, if you’re lucky, reduce group size. Barrel tuners have been used successfully in rimfire benchrest for many years (see photo above). While there are competing theories as to how and why barrel tuners work on rimfire rifles, there is no question that the accuracy of some rimfire barrels can be improved with the addition of a tuner. By changing the position of weights at the end of the barrel, we’ve seen shooters shrink their average group size as well as adjust the “sweet spot” for different lots of rimfire ammo. On the other hand, tuners can be the source of great frustration; some installations may yield little or no benefit. A shooter may have to experiment with a variety of different tuner designs (and weights) to find the optimal configuration.

Gene Bukys Barrel Tuner 333smittyCenterfire Tuners–Still a Work in Progress
In centerfire benchrest competition, the vast majority of competitors do not use tuners, though a few short-range shooters such as Gene Bukys and Jackie Schmidt have enjoyed considerable success. Gene has won major championships with tuned rifles. In 2011 Gene won both the Super Shoot and World Benchrest Championship (WBC), and Gene recently set a new NBRSA Sporter Class Grand Agg Record.

Centerfire benchrest guns typically employ shorter barrels with a much fatter contour (larger diameter) than rimfire rifles. Because centerfire rounds produce much higher pressures and velocities that a 22LR, a centerfire barrel also exhibits much different vibration characteristics than a typical rimfire barrel. Nonetheless, there are pioneers working with centerfire tuners who believe that tuning may be the “next leap forward” in centerfire accuracy.

Shown below is a switch-barrel benchrest rifle built by Forum member Eddie W. of Texas. It features a dual-port Hall “M” action with a ShadeTree Engineering Tuner crafted by Butch Lambert. The gun is designed to take both a 6PPC barrel for group shooting and a 30BR barrel for score shooting. The gun was barreled by Wayne Shaw, and Eddie did the stock work himself. Eddie reports: “It is a very accurate rifle.”

Lambert Tuner

Will we see more tuners on centerfire rifles? Only time will tell. Some folks believe that, since one can easily adjust the loads shot by centerfire guns (by tinkering with the powder charge and seating depth), tuners have limited utility. On the other hand, tuner advocates such as Gene Beggs believe tuners can help keep your group sizes small even as conditions (temperature, humidity) change. Gene believes that, with an appropriate tuner, you can spend less time fiddling with the load specs (changing your powder charge) and instead “dial in” your sweet spot using the tuner.

Lambert Tuner

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April 4th, 2018

Rimfire Barrel Cleaning — ELEY’s Recommended Methods


Here’s a record-setting rimfire benchrest rifle owned by our friend Joe Friedrich.

Eley rimfire barrel cleaning with felt oilThe experts at ELEY Limited, top rimfire ammo-maker, have posted a helpful guide to cleaning rimfire barrels. We reprint highlights of the article below, but we suggest you read the full article on the Eley website: How to Clean Your Rifle the ELEY Way.

Editor’s Comment: This is not the only way to clean a rimfire barrel. There are other procedures. This is the method recommended by ELEY based on decades of experience with the top smallbore shooters in the world, including many Olympic Gold Medalists. Some shooters have been very successful cleaning less frequently, or using different types of solvents. The ELEY method is a good starting point.

Rimfire Barrel Cleaning

1. Clean the extension tube with a 12 gauge brush and felt or tissue moistened with solvent.

ELEY-how-to-clean-your-rifle-cleaning-step-1

2. Smoothly insert a cleaning rod guide into the receiver.

ELEY-how-to-clean-your-rifle-cleaning-step-2-cleaning-rod-guide

3. Apply a dry felt to the cleaning rod adapter and push it through the barrel to the muzzle in one slow steady movement. As the felt is dry it may feel stiff.

ELEY-how-to-clean-your-rifle-cleaning-step-3-apply-dry-felt ELEY-how-to-clean-your-rifle-cleaning-step-3-apply-dry-felt-through-the-barrel

4. Remove the soiled felt and pull back the cleaning rod.

ELEY-how-to-clean-your-rifle-cleaning-step-4-remove-felt

(more…)

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February 16th, 2018

A Slice of (Barrel) Life — Inside Look at Barrel Erosion

So what does a “worn-out” barrel really look like? Tom Myers answered that question when he removed a 6.5-284 barrel and cut it down the middle to reveal throat wear. As you can see, there is a gap of about 5mm before the lands begin and you can see how the lands have thinned at the ends. (Note: even in a new barrel, there would be a section of freebore, so not all the 5mm gap represents wear.) There is actually just about 2mm of lands worn away. Tom notes: “Since I started out, I’ve chased the lands, moving out the seating depth .086″ (2.18 mm). I always seat to touch. My final touch dimension was 2.440″ with a Stoney Point .26 cal collet.”

Except for the 2mm of wear, the rifling otherwise looks decent, suggesting that setting back and rechambering this barrel could extend its useful life. Tom reports: “This was something I just thought I’d share if anyone was interested. I recently had to re-barrel my favorite prone rifle after its scores at 1,000 started to slip. I only ever shot Sierra 142gr MatchKings with VV N165 out of this barrel. It is a Hart and of course is button-rifled. I documented every round through the gun and got 2,300 over four years. Since I have the facilities, I used wire EDM (Electro Discharge Machining) to section the shot-out barrel in half. It was in amazingly good shape upon close inspection.”

Tom could have had this barrel set back, but he observed, “Lately I have had to increase powder charge to maintain 2,950 fps muzzle velocity. So to set it back would have only increased that problem. [And] I had a brand new 30″ Krieger all ready to screw on. I figured it was unlikely I’d get another full season on the old barrel, so I took it off.”

Permalink Gunsmithing, Tech Tip 6 Comments »
January 26th, 2018

Toast in Six Seconds — The Brutal Truth of Short Barrel Life

Stopwatch barrel life

This thought-provoking article is one of the 15 most popular Daily Bulletin features over the last 12 months. We are republishing this story today for readers who may have missed it the first time around…

Here’s a little known fact that may startle most readers, even experienced gunsmiths: your barrel wears out in a matter of seconds. The useful life of a typical match barrel, in terms of actual bullet-in-barrel time, is only a few seconds. How can that be, you ask? Well you need to look at the actual time that bullets spend traveling through the bore during the barrel’s useful life. (Hint: it’s not very long).

Bullet-Time-in-Barrel Calculations
If a bullet flies at 3000 fps, it will pass through a 24″ (two-foot) barrel in 1/1500th of a second. If you have a useful barrel life of 3000 rounds, that would translate to just two seconds of actual bullet-in-barrel operating time.

Ah, but it’s not that simple. Your bullet starts at zero velocity and then accelerates as it passes through the bore, so the projectile’s average velocity is not the same as the 3000 fps muzzle velocity. So how long does a centerfire bullet (with 3000 fps MV) typically stay in the bore? The answer is about .002 seconds. This number was calculated by Varmint Al, who is a really smart engineer dude who worked at the Lawrence Livermore Laboratory, a government think tank that develops neutron bombs, fusion reactors and other simple stuff.

On his Barrel Tuner page, Varmint Al figured out that the amount of time a bullet spends in a barrel during firing is under .002 seconds. Al writes: “The approximate time that it takes a 3300 fps muzzle velocity bullet to exit the barrel, assuming a constant acceleration, is 0.0011 seconds. Actual exit times would be longer since the bullet is not under constant acceleration.”

We’ll use the .002 number for our calculations here, knowing that the exact number depends on barrel length and muzzle velocity. But .002 is a good average that errs, if anything, on the side of more barrel operating life rather than less.

So, if a bullet spends .002 seconds in the barrel during each shot, and you get 3000 rounds of accurate barrel life, how much actual firing time does the barrel deliver before it loses accuracy? That’s simple math: 3000 x .002 seconds = 6 seconds.

Stopwatch barrel lifeGone in Six Seconds. Want to Cry Now?
Six seconds. That’s how long your barrel actually functions (in terms of bullet-in-barrel shot time) before it “goes south”. Yes, we know some barrels last longer than 3000 rounds. On the other hand, plenty of .243 Win and 6.5-284 barrels lose accuracy in 1500 rounds or less. If your barrel loses accuracy at the 1500-round mark, then it only worked for three seconds! Of course, if you are shooting a “long-lived” .308 Win that goes 5000 rounds before losing accuracy, then you get a whopping TEN seconds of barrel life. Anyway you look at it, a rifle barrel has very little longevity, when you consider actual firing time.

People already lament the high cost of replacing barrels. Now that you know how short-lived barrels really are, you can complain even louder. Of course our analysis does give you even more of an excuse to buy a nice new Bartlein, Krieger, Shilen etc. barrel for that fine rifle of yours.

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June 2nd, 2017

Bore Cleaning 101: Speed Up the Job with a Wash Bottle

Wash Bottle

rifle bore cleaner bottle

Small patches are not very efficient at distributing bore cleaning liquids inside your bore. The problem with a tight-fitting patch is that the solvent gets squeezed off in the first few inches. You can switch to a smaller jag, or a bore mop, but there is an even better way to get an ample amount of solvent in your bore. Just spray directly into the bore with a wash bottle, an inexpensive plastic bottle with an L-shaped dispensing neck, tapered at the end.

When using the wash bottle, you can either just plug the breech and spray from the muzzle end (where most copper fouling is), or, alternately, put the wash bottle neck directly in the chamber and spray forward. When spraying from the chamber forward, you may need to use a rubber O-Ring to seal off the action… depending on the bore size and the particular wash bottle’s neck spout diameter. We prefer to plug the breech ans squirt from the muzzle.

Bottle Solvent Application Great for Smaller Bores
Using wet patches or wet brushes is an inefficient way to really saturate the tight bores of 17s, 20s, and 22s. Even with a cotton bore mop, most of the solvent will be squeezed out before it gets to the end of the bore, where most copper fouling occurs. For these smaller 17, 20, and 22-caliber bores, you can just take the wash bottle and stick the tapered nozzle right in the chamber. The tapered end will press fit in the throat, sealing off the chamber. With the barrel slightly nose-down, give the bottle a couple good squirts until the solvent mists out the muzzle. In just a few seconds, this will put more solvent in the bore than a half-dozen wet patches.

A solvent-filled wash bottle is also handy for wetting your brushes. It’s much easier to saturate a bore brush (without spilling solvent on your stock), by using the wash bottle. You can get wash bottles from USPlastic.com, Amazon.com, or lab supply stores.

Permalink Reloading, Tech Tip 2 Comments »
February 26th, 2017

A Few Seconds at Best — The Short Operating Life of Barrels

Stopwatch barrel life

Here’s a little known fact that may startle most readers, even experienced gunsmiths: your barrel wears out in a matter of seconds. The useful life of a typical match barrel, in terms of actual bullet-in-barrel time, is only a few seconds. How can that be, you ask? Well you need to look at the actual time that bullets spend traveling through the bore during the barrel’s useful life. (Hint: it’s not very long).

Bullet-Time-in-Barrel Calculations
If a bullet flies at 3000 fps, it will pass through a 24″ (two-foot) barrel in 1/1500th of a second. If you have a useful barrel life of 3000 rounds, that would translate to just two seconds of actual bullet-in-barrel operating time.

Ah, but it’s not that simple. Your bullet starts at zero velocity and then accelerates as it passes through the bore, so the projectile’s average velocity is not the same as the 3000 fps muzzle velocity. So how long does a centerfire bullet (with 3000 fps MV) typically stay in the bore? The answer is about .002 seconds. This number was calculated by Varmint Al, who is a really smart engineer dude who worked at the Lawrence Livermore Laboratory, a government think tank that develops neutron bombs, fusion reactors and other simple stuff.

On his Barrel Tuner page, Varmint Al figured out that the amount of time a bullet spends in a barrel during firing is under .002 seconds. Al writes: “The approximate time that it takes a 3300 fps muzzle velocity bullet to exit the barrel, assuming a constant acceleration, is 0.0011 seconds. Actual exit times would be longer since the bullet is not under constant acceleration.”

We’ll use the .002 number for our calculations here, knowing that the exact number depends on barrel length and muzzle velocity. But .002 is a good average that errs, if anything, on the side of more barrel operating life rather than less.

So, if a bullet spends .002 seconds in the barrel during each shot, and you get 3000 rounds of accurate barrel life, how much actual firing time does the barrel deliver before it loses accuracy? That’s simple math: 3000 x .002 seconds = 6 seconds.

Stopwatch barrel lifeGone in Six Seconds. Want to Cry Now?
Six seconds. That’s how long your barrel actually functions (in terms of bullet-in-barrel shot time) before it “goes south”. Yes, we know some barrels last longer than 3000 rounds. On the other hand, plenty of .243 Win and 6.5-284 barrels lose accuracy in 1500 rounds or less. If your barrel loses accuracy at the 1500-round mark, then it only worked for three seconds! Of course, if you are shooting a “long-lived” .308 Win that goes 5000 rounds before losing accuracy, then you get a whopping TEN seconds of barrel life. Anyway you look at it, a rifle barrel has very little longevity, when you consider actual firing time.

People already lament the high cost of replacing barrels. Now that you know how short-lived barrels really are, you can complain even louder. Of course our analysis does give you even more of an excuse to buy a nice new Bartlein, Krieger, Shilen etc. barrel for that fine rifle of yours.

Permalink Gunsmithing, Tech Tip 2 Comments »
January 14th, 2017

TECH TIP: How To Cast Chambers Using Cerrosafe

Cerrosafe Chamber casting bismuth

There are many reasons you might want to make a chamber cast. You may have acquired an older rifle and need to verify the chamber dimensions. Or, if you have a new reamer, you may want to check the exact “cut” dimensions against the blueprint specs. A chamber casting is also valuable if you run across a firearm that you believe has a custom barrel on it and you want to find out the dimensions of the chamber. Lastly, you may want to prepare a chamber casting to be used in the making of custom dies. (Most reloading die makers know how to work from Cerrosafe chamber casts.)

Cerrosafe Chamber CastingCerrosafe is a metal alloy that has some unique properties which make it ideal for chamber casting. First, it has a relatively low melting point of 158 to 190° Fahrenheit. This makes it easy for the handloader to melt the Cerrosafe in his home shop. Second, it shrinks slightly during cooling which allows it to be extracted from the chamber easily. It then re-expands to the chamber’s original size after about one hour at room temperature. After cooling for about 200 hours, the chamber cast will expand to about .0025″ larger than the actual chamber size.

One of our Forum members has done many Cerrosafe castings and he offers this smart advice:

1. Remove the barrel from the action to make the pour much easier. If you don’t remove the barrel, it can be hard to pour through the action (even with a funnel) and can make a mess if you’re not careful.
2. Pre-heat the barrel for 5-10 minutes in the oven on the very lowest setting (170° F in my oven). (DON’T overdo it!). Allow to cool for a couple minutes so you can pick it up and it is under 120° F. Pre-heating the barrel helps the Cerrosafe stay liquid as you pour the casting. This helps ensure a good, complete fit to the chamber.

Brownells has an article about Cerrosafe chamber casting that explains how to use this unique material:

How to Use Cerrosafe for Chamber Casting
The basic ingredient of Cerrosafe is bismuth. Bismuth is a heavy, coarse, crystalline metal which expands when it solidifies, up to 3.3% of its volume. When bismuth is alloyed with other metals, such as lead, tin, cadmium and indium, this expansion is modified according to the relative percentages of bismuth and other components present. As a general rule, bismuth alloys of approximately 50% bismuth exhibit little change of volume during solidification. Alloys containing more than this tend to expand during solidification and those containing less tend to shrink during solidification.

What all this means for the gunsmith is that you can make chamber castings using only Cerrosafe and a few, simple hand tools. To make a chamber casting, first clean and degrease the chamber. Use a tight-fitting, cotton patch that’s wrapped around a bore mop or brush to plug the bore just ahead of the throat. I usually leave the cleaning rod attached to the plug until it’s time to remove the plug. Melt the entire bar of Cerrosafe in a heatproof container that you can easily pour the hot Cerrosafe out of. You can use a propane torch or heat over a hot plate or the burner of a stove. Cerrosafe melts easily at 158°-195° F. While the casting metal is still liquid, stir very well, skim off the dross, and pour your chamber. The real trick with Cerrosafe is not to overheat it. If you heat the solid slowly, and keep it within the required temperature range, you shouldn’t get any dross.

Note the time the casting was poured. The casting will take only a very short time to solidify, usually within a minute. Wait 30 minutes and then remove the plug from the bore. Turn the muzzle upward and the casting will fall from the chamber. At 30 minutes after initial solidification, Cerrosafe shrinks slightly, so removal is very easy. Allow the new casting to cool thoroughly then measure the casting exactly one hour from the time it was cast. The casting will give you an exact measurement of the chamber. Cerrosafe casting metal can be used over and over. Remelt the entire amount back together and pour the Cerrosafe into a small mold of the appropriate size. Always melt the entire Cerrosafe ingot to make a chamber casting. For best results, never cut off, or use, just a part of the ingot.

Permalink Gunsmithing, Tech Tip 5 Comments »
September 18th, 2016

CGI Magic — 3D Animation of Pistol Rounds Being Fired

GECO Ruag Ammotec RWS ammo 3D animation video

Here’s a very cool 3D Animation showing pistol rounds being fired. Computer-generated graphics provide a look inside the cartridge at the moment of ignition as the primer fires and the flame front moves through the ignited powder. It’s really kind of mesmerizing. If you’ve every wondered just what happens inside your cartridges the moment that firing pin strikes, then watch this video…

Watch Video to See Handgun Ammo Being Chambered and Fired:

GECO Ruag Ammotec RWS ammo 3D animation videoThis animated video from German ammo-maker GECO (part of the Swiss RUAG group of companies) reveals the inside of a pistol cartridge, showing jacket, lead core, case, powder and primer. Employing advanced 3D rendering and computer graphics, the video shows an X-ray view of ammo being loaded in a handgun, feeding from a magazine.

Then it really gets interesting. At 1:32 – 1:50 you’ll see the firing pin strike the primer cup, the primer’s hot jet streaming through the flash-hole, and the powder igniting. Finally you can see the bullet as it moves down the barrel and spins its way to a target. This is a very nicely-produced video. If you’ve ever wondered what happens inside a cartridge when you pull the trigger, this video shows all. They say “a picture’s worth a thousand words”… well a 3D video is even better.

GECO Ruag Ammotec RWS ammo 3D animation video

GECO Ruag Ammotec RWS ammo 3D animation video

GECO Ruag Ammotec RWS ammo 3D animation video

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