August 5th, 2016
Understanding Twist: Bullet Stabilization
by Sierra Bullets Ballistic Technician Paul Box for Sierra Bullets Blog.
Based on the questions we get on a daily basis on our 800 (Customer Support) line, twist is one of the most misunderstood subjects in the gun field. So let’s look deeper into this mystery and get a better understanding of what twist really means.
When you see the term 1:14″ (1-14) or 1:9″ twist, just exactly what does this mean? A rifle having a 1:14″ twist means the bullet will rotate one complete revolution every fourteen inches of the barrel. Naturally a 1:9″ turns one time every nine inches that it travels down the barrel. Now, here’s something that some people have trouble with. I’ve had calls from shooters thinking that a 1:14″ twist was faster than a 1:9″ because the number was higher with the 1:14″. The easiest way to remember this is the higher the number, the slower the twist rate is.
Now, the biggest misconception is that if a shooter has a .223 with a 1:8″ twist, his rifle won’t stabilize a 55gr bullet or anything lighter. So let’s look at what is required. The longer a bullet is for its diameter, the faster the twist has to be to stabilize it. In the case of the .223 with a 1:8″ twist, this was designed to stabilize 80gr bullets in this diameter. In truth the opposite is true. A 1:8″ will spin a 55gr faster than what is required in order to stabilize that length of bullet. If you have a bullet with good concentricity in its jacket, over-spinning it will not [normally] hurt its accuracy potential. [Editor’s Note: In addition, the faster twist rate will not, normally, decrease velocity significantly. That’s been confirmed by testing done by Bryan Litz’s Applied Ballistics Labs. There may be some minor speed loss.]
Many barrel-makers mark the twist rate and bore dimensions on their barrel blanks.
Think of it like tires on your truck. If you have a new set of tires put on your truck, and they balance them proper at the tire shop, you can drive down a street in town at 35 MPH and they spin perfect. You can get out on the highway and drive 65 MPH and they still spin perfect. A bullet acts the same way.
Once I loaded some 35gr HP bullets in a 22-250 Ackley with a 1:8″ twist. After putting three shots down range, the average velocity was 4584 FPS with an RPM level of 412,560. The group measured .750″ at 100 yards. This is a clear example that it is hard to over-stabilize a good bullet.
Twist-rate illustration by Erik Dahlberg courtesy FireArmsID.com. Krieger barrel photo courtesy GS Arizona.
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July 14th, 2016
Here’s a new barrel option for Savage shooters. Proof Research, a leader in composite barrel production, now offers “Pre-Fit” barrels for Savages. These barrels come chambered and threaded for Savage actions. Pre-Fits are easy to install — just spin them on, set the headspace with gauges, and tension the barrel nut. (Proof Research does recommend enlisting a gunsmith to help with the process.)
With a finished weight under three pounds, these new Pre-Fit barrels are much lighter than conventional all-steel barrels. Proof Research claims that they are “less than half the weight of comparably-sized steel barrels.” But you will pay dearly for that weight savings. As sold by Stocky’s Stocks, these Proof Research Pre-Fits cost $846.99, more than twice what all-steel Pre-Fit barrels from Criterion or Pac-Nor cost. Criterion Barrels currently charges $370.00 for a 26″ Savage or Rem/Age Pre-Fit.
Proof Research claims that its carbon-wrapped barrels shed heat faster than an all-steel barrel. Jason Lincoln, Proof Research’s VP of Engineering, claims that his company’s composite barrels can cool 50% faster than steel barrels, offering reduced point-of-impact shift during extended strings of fire. Is this marketing hype? We have yet to see a definitive test that validates the claims of enhanced cooling…
Proof Research Savage Pre-Fit Options Available
Initially the Pre-Fit barrels will be offered in a “Sendero” profile, very similar to an M24 contour. Available barrel lengths (up to 28″) vary by caliber/chambering (in some cases 24″ is all you can get). The following chamberings and twist rates are currently offered by Stocky’s Stocks:
.223 Rem, 1:8″ Twist
.22-250 Rem, 1:8″ Twist
.243 Win, 1:8″ Twist
6.5 Creedmoor, 1:8″ Twist
6.5×284, 1:8″ Twist
280 Ackley, 1:9″ Twist
7mm Rem Mag, 1:9″ Twist
.308 Win Match, 1:10″ Twist
.300 Win Mag, 1:9.4″ Twist
Proof Research Carbon Technology
Product Tip from EdLongrange. We welcome reader submissions.
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June 11th, 2016
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.
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.
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.
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.
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June 4th, 2016
The BarrelCool is an innovative, 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 $34.99, 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, visit BarrelCool.com. There you’ll find video demos of BarrelCool units in both bolt-action and AR-type rifles.
BarrelCool Range Reports from Forum Members
“Early adopters” of BarrelCool have been impressed so far. Forum 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 Friday. 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.
BarrelCool inventor Bryan Sumoba explains the advantage of Barrelcool: “The challenge with the previous barrel-cooling methods is one would have to be present to run the device, it required additional steps such as running patches down the bore, or it gets in the way of a required empty-chamber flag. BarrelCool now allows the shooter to cool the barrel down simply and easily while having the empty-chamber flag in the firearm.”
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 (more in some cases depending on the barrel contour/length and ambient temperatures). Our customers also report significant reductions in the time it takes to cool down a hot barrel. At a recent 3×1000 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. In most cases, the barrel would still be very warm/hot by the time the next relay started. We placed BarrelCool in his firearm and within 30 minutes, the barrel was back to near-ambient temperature. Other observers mentioned that the air coming out of the muzzle with BarrelCool in the firearm felt like a mini blow dryer.”
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.
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May 5th, 2016
The last half-inch or so of your barrel is absolutely critical. Any damage (or abnormal wear) near the crown will cause a significant drop-off in accuracy. Here are ways you can check the end of your barrel, using a common Q-Tip.
Use Q-Tip for Barrel Inspection
To find out if you have a burr or damage to your crown, you can use an ordinary Q-tip cotton swab. Check the edges of the crown by pulling the Q-tip gently out past the edge of the crown. If you have a burr, it will “grab” the cotton and leave strands behind.
Larry Willis has another way to use a Q-Tip: “Here’s a neat trick that will surprise you with how well it works.” Just insert a Q-Tip into your barrel (like the picture below), and it will reflect enough light so that you can get a real good look at the last half inch of rifling and the crown of your barrel. In most cases you’ll find that this works much better than a flashlight. Larry tells us: “I’ve used this method about a jillion times. Q-Tips are handy to keep in your cleaning supplies anyway. This is a good way to judge approximately how well you are cleaning your barrel when you’re at the range. It’s also the best way to examine your barrel when you’re in the field.”
Larry Willis is the inventor of Innovative Technologies’ Belted Magnum Collet Resizing Die. Larry explains how this die works, and offers other reloading tips on LarryWillis.com.
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April 24th, 2016
With barrels, one wonders “Can a little more length provide a meaningful velocity gain?” To answer that question, Rifleshooter.com performed an interesting test, cutting a .308 Win barrel from 28″ all the way down to 16.5″. The cuts were made in one-inch intervals with a rotary saw. At each cut length, velocity was measured with a Magnetospeed chronograph. To make the test even more interesting, four different types of .308 Win factory ammunition were chronographed at each barrel length.
READ RifleShooter.com .308 Win Barrel Cut-Down Test Article.
Test Barrel Lost 22.7 FPS Per Inch (.308 Win Chambering)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. With a barrel reduction from 28″ to 16.5″, the average speed loss of the four types of .308 ammo was 261 fps total. That works out to an average loss of 22.7 fps per inch. This chart shows velocity changes for all four ammo varieties:
Summary of Findings: The average velocity loss per inch, for all four ammo types combined, was 22.7 FPS. By ammo type, the average loss per inch was: 24.6 (Win 147 FMJ), 22.8 (IMI 150 FMJ), 20.9 (Fed GMM 168gr), and 22.5 (Win 180PP).
Interestingly, these numbers jive pretty well with estimates found in reloading manuals. The testers observed: “The Berger Reloading manual says for the 308 Winchester, ‘muzzle velocity will increase (or decrease) by approximately 20 fps per inch from a standard 24″ barrel’.”
How the Test Was Done
The testers described their procedure as follows: “Ballistic data was gathered using a Magnetospeed barrel mounted ballistic chronograph. At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. Average velocity and standard deviation were logged for each round. Since we would be gathering data on 52 different barrel length and ammunition combinations and would not be crowning the barrel after each cut, we decided to eliminate gathering data on group sizes. Once data was gathered for each cartridge at a given barrel length, the rifle was cleared and the bolt was removed. The barrel was cut off using a cold saw. The test protocol was repeated for the next length. Temperature was 47° F.”
CLICK HERE to Read the Rifleshooter.com Test. This includes detailed charts with inch-by-inch velocity numbers, multiple line charts, and complete data sets for each type of ammo. Rifleshooter.com also offers ballistics graphs showing trajectories with different barrel lengths. All in all, this was a very thorough test by the folks at RifleShooter.com.
Much Different Results with 6mmBR and a Longer Barrel
The results from Rifleshooter.com’s .308 barrel cut-down test are quite different than the results we recorded some years ago with a barrel chambered for the 6mmBR cartridge. When we cut our 6mmBR barrel down from 33″ to 28″, we only lost about 8 FPS per inch. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was 5″ longer than Rifleshooter.com’s .308 Win start length. Velocity loss can be more extreme with shorter barrel lengths (and bigger cartridges). Powder burn rates can also make a difference.
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April 19th, 2016
Are you trying to decide what components to use for your next F-Class build, or are you looking to upgrade your current rig? Wonder what the “big dogs” in the sport have selected as their hardware? Here’s what United States F-Open team members are using. The most popular chambering is the .284 Winchester, followed by the 7mm Walker (a 40° .284 Winchester Improved). Kelbly and BAT actions are the most popular, and nearly all team members are using cut-rifled barrels. A wide variety of stocks are used, with PR&T holding a slight edge over second-place McMillan.
Click Image Below for Larger Version:
Story Tip from Dominion of Canada Rifle Association.
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March 29th, 2016
Criterion Barrels Inc. (CBI) has a policy of rewarding excellence. As a way of supporting top shooters, Criterion will provide a new, free barrel to any shooter who sets or ties a national record when using a Criterion product. To explain, you get a new Criterion barrel for free if you set (or tie) a national shooting record using a Criterion barrel on your rifle.
Criterion Barrels hopes to increase awareness of its free barrel for record sectors program. Over the last few years a number of F-Class and vintage military competitors have benefited from this program, receiving a complimentary barrel of their choice after setting a new national record in their shooting discipline. Past record breaking shooters have included David Mark Honeycutt (with a 300-yard F-Class score of 600-50X), Samantha Huhtala (four records set in 600-yard F-TR competition), and Victor Betzold (M1 Carbine with a score of 375-6X).
Criterion may, in the future, create a rewards program for winners of national, regional, and local rifle matches. Potential earned rewards by match winners could include equipment sponsorships, barrel discounts, and free apparel items.
Set a Record with a Criterion Barrel? Then Give Criterion a Call…
If you or someone you know has set a pending national record with a Criterion barrel, have the shooter contact Criterion Barrels. Send email to contact[at]criterionbarrels.com or call (262) 628-8749.
Once the shooter’s information is verified and the record is confirmed by the governing body of their appropriate shooting discipline, the order will be processed and shipped to the new record-holder.
About Criterion Barrels, Inc.:
Criterion Barrels, Inc. was founded in 1999 as a division of Krieger Barrels, Inc. in response to demands of rifle builders and firearms manufacturers for quality match grade barrels at a lower cost. Our company is now completely independent from Krieger Barrels, featuring a separate facility, personnel, and ownership.
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March 25th, 2016
Here’s a record-setting rimfire benchrest rifle owned by our friend Joe Friedrich.
The 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.
2. Smoothly insert a cleaning rod guide into the receiver.
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.
4. Remove the soiled felt and pull back the cleaning rod.
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March 17th, 2016
The Lyman Borecam is an electro-optical borescope with a digital display. You can record “stills” on a SD card. This is one of the hottest products on the market right now — so hot that it has been sold out for weeks. But Grafs.com just got a shipment of Borecams (item LY04055), and the price is more than competitive. Right now Grafs has the Borecam in stock for $259.99 with free shipping (after a single $7.95 handling fee). That price is $40.00 less than some other online vendors are charging.
This is a good product. Guys who purchased the Lyman Borecam are very happy. If you don’t have one yet, now may be the time to “pull the trigger”. After this article goes live, we expect Grafs.com to sell out quickly. Graf’s inventory may be gone by end-of-day today.
Our British friend Vince Bottomley did an extensive review, giving the Lyman Borecam high praise. Vince says serious shooters should definitely acquire one of these tools: “In my opinion, this product is one of the very best to come along in recent years and I predict that the demand for these [Lyman Borecams] will be very heavy. I would advise you to place an order as quickly as possible if you want one.” Vince adds: “If I were to replace my [Hawkeye optical borescope] today with another Hawkeye, it would cost me well over £700 [$1015 USD]. Stick on a video adapter and we are looking at four figures. That’s what makes the new Lyman digital borescope so attractive — at around [$260.00 USD] including a monitor — it’s an absolute steal!”
The system really works. Many of our Forum members have the system and they say it functions very well and is “very easy to set up and use”. Here’s what an Optics Planet Borecam buyer wrote: “I have used Hawkeye borescopes and know their quality. The Lyman worked as advertised and is a great tool for checking for leading, cleanliness of bore, and bore wear. The compact size, ability to take pictures, and store them are a big plus.”
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February 18th, 2016
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 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.
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January 24th, 2016
Editor: This article appears on the Criterion Barrels website. It provides good, conservative advice about barrel cleaning. Understand that cleaning methods may need to be adapted to fit the amount and type of fouling (and the particular barrel). In general, we do try to minimize brushing, and we follow the procedures Criterion recommends respecting the crown/muzzle. We have also had very good success using wet patches followed by Wipe-Out bore foam. Along with the practices outlined by Criterion below, you may want to try Wipe-Out foam. Just be sure to use a fitted cleaning rod bore guide, to keep foam out of the action recesses and trigger assembly.
What is the Best Way to Clean a Rifle Barrel?
We are asked this question quite frequently alongside requests for recommended break-in procedures. Improper barrel cleaning methods can damage or destroy a barrel, leading to diminished accuracy or even cause a catastrophic failure. When it comes to barrel maintenance, there are a number of useful techniques that we have not listed. Some techniques may work better with different barrel types. This series of recommendations is designed to incorporate a number of methods that the Criterion Barrels staff has used successfully both in the shop and on their personal rifles. Please feel free to to list your own recommendations in the below comments section.
We recommend the use of the following components during rifle cleaning:
• Cloth patches (sized for the appropriate caliber)
• Brass jag sized properly for your bore
• One-piece coated cleaning rod
• General bore cleaner/solvent (Example: Hoppes #9)
• Copper solvent of your choosing (Example: Sweets/KG 12)
• Fitted cleaning rod bore guide
• Plastic AP brush or toothbrush
• Plastic dental picks
• CLP or rust preventative type cleaner
There are a number of schools of thought relating to the frequency in which a barrel should be cleaned. At minimum we recommend cleaning a barrel after each shooting session to remove condensation, copper, and carbon build-up. Condensation is the greatest immediate threat, as it can cause the barrel to rust while the rifle sits in storage. Copper and carbon build-up may negatively impact future barrel performance, increasing the possibility of a failure in feed or function. Fouling should be removed whenever possible.
The below tips will help limit the wear of different parts of your barrel during routine maintenance, helping extend the life of the barrel and improving its performance.
The crown is the portion of the barrel where the bullet loses contact with the lands and grooves and proceeds to exit the firearm. The area most critical to accuracy potential is the angle where the bullet last touches the bore of the barrel.
Avoid damage to this area by using a plastic toothbrush and CLP type cleaner to scrub the crown from the exterior of the barrel. Even the most minimal variation in wear to the crown will negatively impact barrel performance, so be careful to avoid nicking or wearing away this part of the barrel.
Reducing Cleaning Rod Wear to the Crown
When running a patch through the barrel, place the muzzle about a ¼” from a hard surface that runs flat at a perpendicular angle to the cleaning rod’s direction of travel, like a wall or the edge of a work bench (pictured). When the jag impacts the hard surface, retract the cleaning rod and remove the patch.
By withdrawing the jag prior to its exit from the barrel, you are limiting the possibility of the brass dragging upon the crown if the rod is at all bent or misaligned. The soft cloth patch will continue to serve as the point of contact between the jag and the barrel, minimizing potential wear.
If possible, insert the rod through the chamber, pushing it forward toward the muzzle. Some rifles, such as the M1 Garand or M14, will require you to insert the cleaning rod through the muzzle. In these situations the use of a cleaning rod guide is recommended to limit the friction placed upon the crown.
Avoid using cleaning rod segments for scraping carbon from the recessed muzzle of an AR-15 barrel. We used this trick in the Marine Corps to impress the armorers and NCO’s with the cleanliness of our muzzles, but it likely played a significant role in reducing the service life of the rifle barrel in question.
Use a Q-Tip soaked in solvent to remove any copper or carbon residue from the recessed muzzle of an AR-15 barrel. A little bit of remaining carbon on the face of the muzzle will not negatively affect bullet travel so long as the crown edge remains consistent around the circumference of the bore.
The Lands and Grooves
This portion of the barrel may experience reduced efficiency due to copper fouling and cleaning rod damage. If copper fouling takes place during the initial break-in of the rifle, make sure to check our barrel break-in article.
For regular maintenance we suggest using a single piece coated cleaning rod rather than the traditional segmented rod or bore snake. While segmented rods and bore snakes may be convenient for field use, the corners between the segments may bow out and catch on the lands, scraping along the length of the rifling. Residual grit and particles from expended cartridges may also get caught between segments, resulting in an abrasive surface working its way down the length of the barrel. Most bore snakes will remove significant amounts of carbon fouling, but may fall short in the removal residual carbon buildup and copper fouling during deep cleaning. Good rods can be sourced from multiple manufacturers, but we have found good results using both Pro-Shot and Dewey brand products.
General cleaning requires the use of patches rather than nylon or brass bore brushes. Brass brushes may be required when aggressive cleaning is required, but can lead to unnecessary wear on the barrel if used frequently. This is not due to the nature of the soft brushes themselves, but from the abrasive particles of grit that become embedded in the material that is being run repeatedly through the bore. We recommend the use of bore guides when cleaning from both the muzzle and breech. These bore guides will help serve to protect the crown and throat from cleaning rod damage.
If significant resistance develops while running the cleaning rod through the bore, no attempt should be made to force it in further. Back the rod out and inspect the barrel to determine the cause of the resistance. The jag may be pushing between a bore obstruction and the rifling, digging a divot into the barrel before pushing the obstruction back through the muzzle. One way to minimize the risk of a stuck rod is by utilizing a slightly smaller patch during the initial push.
The process of cleaning the length of the rifling is relatively straightforward:
1. Check to make sure the rifle is safely unloaded.
2. Carry out any necessary disassembly procedures prior to cleaning.
3. Remove bolt (if possible) and insert fitted cleaning rod bore guide in action.
4. Soak a patch in bore solvent (similar to Hoppes #9).
5. Center and affix the patch on the brass jag, inserting it into the chamber end of the barrel. A misaligned patch may cause the jag to damage the lands of the rifling, so make sure the patch is centered on the jag.
6. Run the patch the full length of the barrel, retracting it upon reaching the end of the muzzle.
7. Let the solvent sit for a minute.
8. Continue to run patches through the bore until carbon residue is minimized.
9. Run a dry patch through the bore to ensure carbon residue has been removed.
10. Soak a patch in copper solvent (Sweet’s or KG-12).
11. Run the patch through the bore, leaving it to sit for 3-5 minutes (do not let solvent sit for more than 15 minutes.*)
12. Repeat this process until no blue residue remains on the patches.
13. Run a patch of Hoppes #9 and a dry patch through the bore to neutralize the copper solvent.
14. Inspect the barrel prior to reassembling the rifle, verifying that no bore obstructions remain.
*Please note that some ammonia-based copper solvents may prove to be corrosive if left sitting in the barrel for an extended period of time. It is essential that these solvents be removed within 15 minutes to avoid ruining the bore.
Proper cleaning of the chamber is a critical component of a general cleaning procedure. Carbon rings can build up near the neck and throat of the chamber wall, leading to feeding malfunctions and pressure spikes inside the chamber.
The chamber can be the trickiest part of the barrel to effectively clean, due to its fluctuation in size and the awkward ergonomics often required to remove carbon residue. Numerous chamber specific devices have been created to address this problem, and while some should be avoided (steel chamber brushes), others can be used to great effect (cleaning stars and plastic dental picks). The simplest approach to cleaning a chamber is to apply solvent to a couple patches, and use the cleaning rod to spin the wadded up patches inside the confines of the chamber. This should aid in removing any excess carbon. A Q-Tip can be used to reach portions of the chamber unreached by patches.
The Barrel Exterior
While the condition of the crown, rifling, and chamber are essential to firearm performance, the finish of the exterior should also be cleaned after handling. Condensation, humidity, direct water contact, and salt residue from skin contact can cause rust or corrosion. An application of anti-corrosion products is recommended when placing a firearm into deep storage for an extended period of time. [Editor: AccurateShooter.com recommends Corrosion-X or Eezox, but other products work well too.]
Finding Cleaning Components
While most cleaning components can be found at your local gun shop, some specialty items may need to be sourced through online retailers such as Brownell’s. Criterion utilizes both Dewey and Pro-Shot brand cleaning components during our day-to-day operations.
Do you have any rifle cleaning tips or tricks not mentioned in the above article? We’d love to hear about them. You can post your comments below.
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January 19th, 2016
Lyman’s digital BoreCam is one of the hottest rifle/gunsmithing accessories on the market right now. The product sells out quickly whenever a vendor gets a few in stock. Make no mistake, this is a good product that works well, and, at around $300.00, is it affordable for most shooters. The BoreCam provides vital information about your bore and chamber, and has the ability to save images to an SD card.
Our British friend Vince Bottomley recently obtained a Lyman BoreCam and put it through its paces. Vince came away very impressed. He says it is an easy-to-use and very capable bore inspection tool at a fraction of the cost of a high-end optical borescope (such as the Hawkeye). Vince says serious shooters should definitely acquire one of these tools: “In my opinion, this product is one of the very best to come along in recent years and I predict that the demand for these [Lyman BoreCams] will be very heavy. I would advise you to place an order as quickly as possible if you want one.”
READ Full Review by Vince Bottomley for Target Shooter Magazine
Here are highlights from Vince’s review of the Lyman BoreCam: “If I were to replace my [Hawkeye optical borescope] today with another Hawkeye, it would cost me well over £700 – stick on a video adapter and we are looking at four figures. That’s what makes the new Lyman digital borescope so attractive – at around £250 including a monitor – it’s an absolute steal!
But £250 – with a video attachment and photo-capture facility – can this really be a useable borescope? Trust me it is! But what use is a borescope. Why do you need one? Well, whatever you shoot, the condition of your rifle’s bore is critical. And I’m not just talking about a bore that’s ‘shot-out’ – maybe you just aren’t cleaning it thoroughly. Or maybe some defect within the chamber or rifling is preventing your rifle delivering the kind of performance you expect. Even at £700, a borescope can be cost-effective – if it saves you the cost of just one new barrel.”
Vince explained how the BoreCam can quickly diagnose problems in a barrel: “A customer started to have difficulty chambering rounds in his 308 Target Rifle…. The borescope quickly revealed the problem – a hard ring of copper and carbon had built-up immediately in front of the chamber. When you use a bore-guide (and you always should do) it can sometimes ‘protect’ this first bit of the bore from the cleaning-brush. Although the rest of the bore was spotless, this tiny section was not. Once we knew where the problem was, it was simple matter to carefully clean it up.”
“A borescope will tell you if your cleaning regime is effective, or inspect for throat-erosion and the general condition of the rifling. In addition, it’s very useful to the gunsmith for inspecting newly-cut chambers – making sure they are free from scoring and other machining defects.” Vince also recommends using the BoreCam to inspect barrel crowns: “Tiny burrs can often be present on newly-cut crowns and even the minutest of damage to a crown… can play havoc with accuracy. For the serious shooter, you could say that a borescope is the equivalent of a doctor’s stethoscope.”
CLICK HERE to Read Full Review (with detailed Specs and more photos).
The Ugly Truth Revealed
Here are some inside-the-barrel photos Vince took with the Lyman BoreCam. Vince notes: “This barrel came out of the scrap-bin, but someone had actually been shooting this rifle before he finally gave up and came in for a new barrel. Shooting a barrel in this condition is really throwing good money down range! Buy a borescope and stop shooting long before your barrel gets into this state!”
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December 24th, 2015
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.
Centerfire 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.”
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.
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December 12th, 2015
Here’s an interesting $75 product that can help you “tune” the cycling force of your AR-platform rifle. Wilson Combat offers an Adjustable Lo-Profile AR Gas Block for direct gas impingement AR-type rifles. Wilson Combat’s adjustable gas block replaces a standard AR gas block and allows you to tune your AR’s gas system for smoother cycling and enhanced reliability. Wilson Combat explains: “Adjusting your rifle’s gas port will lower or increase your bolt’s cyclic rate. This tailors your rifle’s performance to your unique needs.” When varmint hunting with an AR, we like a less-energetic ejection so the brass lands close to the gun (and doesn’t tag fellow shooters).
A simple adjustment of the hex screw at the front of the block modulates the gas volume allowing you to tune your rifle’s function to your favorite loads. This is very handy when shooting non-standard AR calibers, unusual hand-loads, or suppressed rifles. Adjustable Gas Block systems are sold as complete kits starting at $74.95. Wilson Combat offers two diameters (.750″, .937″) and three lengths (Carbine Length, Mid-Length, & Rifle Length), so you can select the right dimensions for your rifle configuration and barrel diameter. The blocks are Chromoly steel with a Melonited finish.
- Adjustable Gas Block (Melonite Finish)
- Adjustment Set Screw (Installed)
- Straight Gas Tube (Installed, Gas Tube Pin Installed)
- 12″-Long Allen Wrench to Adjust Inside Handguard
- $74.95 MSRP
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November 30th, 2015
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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October 17th, 2015
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.
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