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June 8th, 2022

Pre-Fit Solution — Don’t Waste Time with a Funky Factory Barrel

Savage Pre-Fit Criterion Barrel

Get WAY Better Groups with New Criterion Pre-Fit Custom Barrel

Savage Criterion Barrel

Savage Criterion BarrelIn our Shooters’ Forum, you’ll find a lengthy thread about accuracy problems with a Savage LRPV, chambered in 6mmBR. The gun would repeatedly split groups at 100 yards, and at 300 yards, the “flyers” would open up the groups to 1.5 MOA or larger. Interestingly, the factory test target (at right) showed a split group — not a good sign.

The gun’s owner, forum member LR_Shooter, tried a variety of tweaks: “I did this, done that… [changed] torque, tang floated, bedded action, recut chamber, and [adjusted firing pin]”. But nothing really helped. Frustrated, LR_Shooter asked his fellow Forum members for help. Much advice was proffered, including the novel idea of removing the middle action screw in the Savage 3-screw target action. Some of the advice proved helpful, but none of the suggested remedies produced a major improvement. This rifle, out of the box, tossed flyers and no amount of tweaking (or changes in shooting technique) really cured the basic problem. That is, until, the factory barrel got replaced…

New Criterion Pre-Fit Barrel Works Wonders
LR_Shooter acquired a Criterion pre-fit barrel from Jim Briggs at Northland Shooters Supply (NSS). These pre-fits are designed for easy installation with the standard Savage barrel nut. Wouldn’t you know it, with a new 30″ heavy-contour barrel on the LRPV, the gun started shooting way better. No more crazy fliers, no more split groups, no more excessive vertical. And the improvement came without any other major modifications. LR_Shooter reports: “I got a replacement barrel from Jim at NSS. It is a 30″ bull Criterion barrel. So far, without playing with torque screws and having my old setup… I’m very satisfied with the barrel I got. Now I have no problem getting [groups] under 0.25 MOA. Finally this thing can shoot!” The targets below, shot with the new Criterion barrel, speak for themselves. The left target was shot at 100 yards, while the target on the right was shot at 300 yards (very impressive).

Targets Shot with Savage LRPV Fitted with Criterion Barrel
Savage Criterion Barrel

Read Thread on Savage Accuracy Issues Fixed By Criterion Barrel

Moral of the Story — Sometimes A New Barrel Really Is the Right Solution
All of us have struggled at times with a rifle that won’t live up to expectations. This Editor personally struggled for over a year with a .260 Rem Savage with a factory tube. The gun tended to split groups and the POI walked as the barrel heated. I tried one powder/primer combination after another, working through a variety of seating depths over many months. I was persistent. Out of stubbornness, I just believed that sooner or later I’d find the magic load.

Well folks, sometimes there’s really nothing you can do about a sub-par barrel. It is what it is. To really improve a gun’s accuracy (particularly a gun with a factory tube), you may need to open your wallet and get a quality aftermarket barrel. Spending months trying one recipe after another may simply be an overwhelming waste of powder, bullets, and your precious time.

Albert Einstein supposedly said: “Insanity is defined as doing the same thing over and over again, and expecting different results.” Well that sort of describes my efforts with my .260 Rem. Once I had enough evidence that my barrel split groups no matter what load combo (and seating depth) I tried, it was time to pony up for a new barrel. When I did finally screw on a nice PacNor 3-groove SuperMatch, that Savage suddenly became a true tack-driver. As re-chambered in 6mmBR with the Pac-Nor, in calm conditions, my Savage will now consistently shoot in the twos with heavy bullets, and it can sometimes dip down into the ones with Berger 80gr flat-base bullets. The moral of the story here is simple — don’t waste weeks or months chasing your tail with a barrel that just won’t deliver (after a reasonable amount of testing). Save up for a custom barrel, get it chambered properly, and stop your cycle of frustration.

Permalink Gear Review, Gunsmithing, New Product No Comments »
May 15th, 2022

Sunday Gunday: 20 PPC Pistol — Great for Varmint Adventures

varmint 20 ppc rampro pistol John Seibel
varmint 20 ppc rampro pistol John Seibel

This week’s featured firearm belongs to John “SnakeEye” Seibel, founder of the VarmintsForFun website. In recent years, John has become a “true believer” in the little 20-Caliber cartridges. He says this light-recoiling 20 PPC, Rampro-actioned pistol is perfect for a quick shot on a critter, taken from the front seat of his truck. John tells us: “A long-range pistol is an ideal truck gun in my opinion. It stows in a small area and doesn’t take up the room a rifle does. Just keep ear protection near by at all times! I’ve taken varmints as far as 400+ yards with this 20 PPC pistol, so why would you need a rifle?”

Perspectives on Pistols for the Varmint Hunter

by John Seibel
I decided to try my hand at shooting varmints with a pistol one day when I grew tired of wrestling a rifle around in the truck for a quick shot. Many times when traveling around on the farm you’ll spy a groundhog or fox that usually isn’t more than 200 yards away. A single-shot pistol like the Thompson Contender could fit the bill. With its compact length, around 20 inches, a long-barrel pistol can lay on the truck’s passenger seat for easy access. I usually keep my two leather brick-style sandbags laying beside the console and seat. I have a box made from hard rubber that I lay across the top of the door. I then lay the two bags on top. This makes a nice platform to rest the pistol’s forearm. I like to use a forearm that is at least two inches wide. That lets the gun lay steady—almost like you are shooting from a bench rest. For the shooting hand, I prefer a pistol grip with finger grooves and a slight overhang or flare for the web of your hand.

As for optics, I tried long-eye-relief pistol scopes but they lacked the magnification you need for long-range target shooting or varminting. Those pistol scopes have really long eye-relief because they are designed to work with the pistol held at arm’s length. When shooting at the bench or from a truck that’s not what you want. By the time you find the target and get your eye in the exact location, the varmint has moved on or died of old age! After much fiddling around with pistol-type scopes, I finally decided to use rifle scopes on my long-range pistols. The minimum I use is a 4.5-14×40. Eye relief on a Leupold 4.5-14x40mm is about 3.5 inches at 4.5 power. Field of view is better with rifle scopes too and it’s easier to acquire your target. For this type of shooting a light-recoiling caliber is essential or you will have scope-eye bad! I currently have three long-range pistols and use them to shoot 17M4, 20 PPC, 22 BR, and .223 Rem. The featured gun may be the most accurate of my pistols, and your editor thinks it’s the most handsome of the three.

varmint 20 ppc rampro pistol John Seibel

The Rampro Pistol Project — Working with John Illum
A couple of years ago I called John Illum of Rampro about building the ultimate long-range pistol. It just so happens that John was a big time long-range pistol shooter. I told him that I wanted a gun that didn’t recoil badly and wouldn’t torque when fired. As I am a quadriplegic, with no grip in my hands, the gun had to handle well under recoil so I didn’t drop it. Recoil had to be straight back–no twisting.

Well Illum listened to me and came up with a gun that performs just the way I wanted. Illum suggested a rear grip stock of his own design. It has a 2.25″ wide forearm and a rear grip with a slight palm swell that fits your hand perfectly. Another nice feature is the finger grips. It has an extended overhang or “beavertail” that fits comfortably in the web of your hand. Of course it had to be walnut! I chose Rampro’s STP small action with a PPC bolt. His bolt uses a Sako-type extractor. The action is a single-shot. Being right-handed, I chose a right bolt, left port configuration. This works really well in a pistol. You can load with your left hand and see the round laying in the action–that’s what you want in a pistol without a safety.

Gun Specifications
John Illum’s Rampro actions are chrome-moly steel. Commonly you’d see them blued, but I had him put a brushed nickel finish on the action and rings. From a few feet away it looks like stainless. The trigger is Illum’s own design set at 8 ounces, and there’s no creep that I can detect. The action has Remington barrel threads and will accept Remington type triggers. One neat thing is that the action was milled with an integral recoil lug (much like the current Surgeon Action). And the bolt is milled all in one piece–no soldered-on handles. My only gripe with this bolt handle is that it could be a tad longer, but it still is manageable for a single-shot. You’ll also note how slick and streamlined the scope rings are. Illum made those as well. His rings mount to the action via two screws from the inside of the ring, a very elegant set-up for sure. (I currently have a 6.5-20x40mm Nikon scope on this gun. If I had to do this project over again the only thing I would change would be installing a 30mm scope because I like ‘em!).

The barrel is a PacNor Super-Match heavy taper with flutes milled by John Illum, who did all the gunsmithing on this pistol. Twist rate is 1 in 12 inches, with an 11° crown, polished to a mirror finish. The barrel was bead-blasted on the exterior to cut glare. I had Illum cut a 20 PPC minimum-spec chamber, with a .237″ neck. That way I don’t have to turn necks on the Lapua Brass (220 Russian necked down to .204). This is a varmint gun–there’s no need for turned necks. [Editor’s Note: Rampro is no longer in business. However, John tells us “I haven’t had any problems with the action so far. If I did, most competent gunsmiths could fix them easily.”]

Handgun Handling Tips
If you want to shoot a long-range pistol but have never have shot this kind of gun before, try to find a mentor — someone with a gun like this who can school you a bit in the correct technique. The first thing you notice is that you have no comb or cheek piece to help align your head and neck. And getting used to the optics takes some practice. Most people fit a pistol-type (long eye-relief) scope, but these can be awkward to use, and somewhat frustrating at first — the field of view is very restricted. Move your head very slightly and you can lose the sight picture completely. You can solve that problem by using a standard rifle scope, but that will put your head very close to the eye-piece — just three to four inches. With that arrangement, if you don’t hold the gun correctly … POW instant scope-eye!

Now once you get the hang of shooting a long-range pistol you will find it can be just as accurate as a rifle. But there is a trick to shooting them. Shooting a long-range pistol is a whole new world — you need to hold it just right. If you don’t let the gun roll back a little (i.e. if you grip too hard) you will get vertical stringing. I hold my hand against the back of the grip to guide the gun but let it almost free recoil. Looking at how compact the pistol is, you might think “Hey, this would make an ideal ‘walking-around’ varminter.” Well, that’s not really the case. For real precision shooting a solid benchrest type set-up is a must. You can attach a bipod to a long-range pistol, but you would need a flat surface. A fence-post top would work pretty well without a bipod if you carry a small light bag. Overall though, this type of pistol works best as a sandbag gun. For a walking-around gun, you’d be happier with a rifle I think.

Load Development and Accuracy
When I built this gun, Hornady had just released the 32gr V-Max (see footnote), a good match for my barrel’s 1:12″ twist. I choose the 20 PPC because of the very good Lapua brass (220 Russian parent case). I figured teaming Lapua brass with the little .204 bullet would offer excellent accuracy combined with very low recoil. My expectations were fulfilled. The brass proved to be excellent and the PacNor loved the little V-Max pills.

I tried quite a few different loads and most powders that I tried worked very well. These included: H322, Benchmark, AA 2460, and Reloader 7. Amazingly, with just 14″ of barrel, all of these powders delivered impressive velocities–ranging from 3914 to 4074 fps. I settled on 48 Harrell’s clicks of Accurate Arms (AA) 2460, which drives the 32gr V-Maxs to 3995 fps.

With AA 2460 the gun will shoot in the low 3s at 100 yards consistently — as long as I steer the gun right, which takes some practice. I think groups in the low 0.3″ range is excellent for a non-benchrest factory bullet. Despite having no buttstock to grab, recoil on my 20 PPC pistol is very minimal — it just rocks back into your hand. The main problem is to keep the scope from smacking you, since I used a rifle scope with short eye-relief. Muzzle flash and noise are tolerable but DO NOT shoot one of these without good ear protection. Your ears are very close to the muzzle.

I also have a 20 PPC rifle built on a BAT action with a Richard’s #008 laminated stock cut down in size. That gun’s 1:9″-twist Lilja barrel lets me shoot the Berger 50gr LTB bullets. In the wind, these perform quite a bit better than the 32s. My two favorite loads for the 50 grainers are: a) 26.0gr VV N135, CCI 450 primers, 3615 fps; and b) 27.3gr Hodgdon Varget, CCI 450s, 3595 fps. The BAT 20 PPC also shoots really well with the 40gr V-Max, pushed by N135 and Fed 205M primers.

Pistol Action Legal Issues
One important thing to remember if you build a pistol is to make sure the receiver came from the factory as a pistol and was titled as a pistol. Rifle actions are illegal to use as a pistol. Yes, that’s a nonsensical law, but it’s still on the books. You can use factory pistol actions such as the XP 100.

If you want a new custom action such as a BAT (my favorite), you can order it as a pistol action and when you get it, register it as a pistol. Note, in some states there may be additional fees, waiting periods, or restrictions for pistol actions (as opposed to rifle actions). Check your local laws before ordering the action.

Future Trends in Varmint Hunting — Plenty of Twenties

I think these sub-caliber rounds, both 20s and the 17s, are the future of recreational varminting, at least out to medium distances. The Twenties offer low recoil, excellent accuracy, and components keep getting better and better. The bullet-makers are finally making high-quality bullets in appropriate weights. Compared to something like a 22-250, I’ve noticed that my 20 PPC rifle has a lot less noise, a plus when you want to be quiet around other people and varmints.

The flat trajectory is another big advantage in the field. With the 20 PPC, zeroed at 100 yards, I can pretty much hold dead center and get hits out to 300 yards or so without touching the scope to add elevation. [Editor: The same is true with the 20 Practical cartridge, basically a .223 Rem necked down to .20 Caliber. It has proven very accurate and easy to tune.]

The 20-Caliber cartridges we have now, in particular the 20 PPC and 20 BR, are very well-refined. You don’t have to do a lot of tuning or tinkering to have a very accurate, effective varmint-slayer. In fact, if I could dream up a signature “20 VFF” (Varmints For Fun) cartridge it would basically be the 20 PPC. In truth, nearly any of the popular 17- or 20-Caliber cartridges will perform well if you start with top-quality brass. The sub-calibers have less recoil and burn less powder, and there are very good components for most varmint and target-shooting applications. To me it seems that these small calibers work so well because of good components, low recoil, and efficient cartridge designs (particularly in the VarTarg and PPC cases).

varmint 20 ppc rampro pistol John Seibel

WARNING: For your own safety, ALWAYS reduce all starting charges by 10% and work up carefully! Ambient temperature changes, powder lot variations, and differences in barrel friction can result in significantly increased pressures.

20 PPC LOAD MAP
Bullet GR Maker Powder Charge Primer Case Velocity
fps
Barrel
Twist
Comments
32 Hornady
V-Max
H322 27.6 Rem 7½ Lapua 4000 Lilja 1:12 WarrenB Form Load
32 Hornady
V-Max
AA 2460 29.5 Rem 7½ Lapua 3995 PacNor 1:12 SnakeEye
Pistol Load
32 Hornady
V-Max
H4198 25.1 CCI BR4 Lapua 4222 PacNor 1:12 A. Boyechko Load
39 Sierra
BlitzKing
H322 26.0 Rem 7½ Lapua 3700 Lilja 1:12 WarrenB Load
39 Sierra
BlitzKing
VV N540 28.8 CCI BR4 SAKO 4064 PacNor 1:12 D.Moore, Low 2s
40 Hornady
V-Max
VV N135 27.8 Fed 205m Lapua 3950 Lilja 1:9 SnakeEye Load
50 Berger
LTB
VV N135 26.0 CCI 450 Lapua 3615 Lilja 1:9 SnakeEye Load
50 Berger
LTB
Varget 27.3 CCI 450 Lapua 3595 Lilja 1:9 SnakeEye Load

Footnote: When first manufactured, the small Hornady 20-Caliber V-Max bullet was actually 33 grains, not 32 grains as sold currently. I still have some of the 33-grainers. I’ve observed no functional difference between the 33s and the current 32-grainers.

Permalink - Articles, Bullets, Brass, Ammo, Hunting/Varminting, Tech Tip 1 Comment »
April 30th, 2022

Barrel Tech — Precision Barrel Bore-Honing Technology

Sunnen honing barrel hone CNC computer honer machine Pac-nor

Some custom barrel makers are now honing barrels (after drilling) to improve bore diameter uniformity, smooth the interior finish, and reduce barrel lapping times. For years, large-scale manufacturers of hammer-forged barrels have employed honing. Now the process is being used by smaller, “boutique” barrel-makers. This article explains how and why barrel honing is done. Take the time to watch the video. For anyone with an interest in barrel-making, this video from Sunnen Products Co. is an eye-opener.

Barrel Honing Process Demonstrated (Worth Watching!):

Barrel Bore honing cut-rifled rifling hammer forging accurateshooter.com

For custom barrel makers, honing is a time-saver and cost cutter. A few minutes on a honing machine can cut lapping times in half, leaving a cross-hatched surface finish in single or low double-digit Ra. Honing is the same process used to make diesel fuel injectors with bore roundness and straightness controlled to fractions of a micron (<0.000040"), with surface finish Ra ≤0.15 µm (6 µin).

A key manufacturing process used for hammer-forged barrels is now getting attention from the makers of custom button-rifled barrels. This process is precision bore-honing. Honing produces a high-quality bore surface fast, which is critical to hammer forging. (Why is honing so important with hammer forging? Surface finish is the one feature of the barrel that cannot be controlled in hammer forging. Surface imperfections in a barrel blank tend to be amplified as the blank is formed on the rifling mandrel. And if the bore is chromed afterwards, imperfections in the surface finish become even more obvious.)

Honing dramatically improves bore diameter size uniformity and accuracy, surface finish and roundness throughout the length of the barrel. It can certainly be used in place of a pre-rifling lap. The chief difference between a lapped and honed bore is the direction of the finish lines in the bore. Honing leaves fine spiraling crosshatch lines, while a lap leaves lines going longitudinally in the bore. After rifling the manufacturer can remove the crosshatch finish with a quick lap if desired. Honing is fast, accurate, and can be automated. Its surface quality and geometry can duplicate lapping, except for the longitudinal lines of the lapped finish.

In 2015 Frank Green of Bartlein Barrels told us: “We worked with Sunnen and we did all the initial testing on the prototype machine for them. The machine works great! We ordered and received … a new manufactured machine with the changes we wanted on it and [subsequently] ordered a second one.”

Pac-Nor PacNor Barreling honing hone Sunnen lapping barrel
The Sunnen hone secures the barrel blank in a 3-jaw chuck, with honing oil pumped into one end while the tool works from the opposite end. Sunnen’s specialized Long Bore Tool uses metal-bond diamond or CBN superabrasives to quickly remove reamer marks, waviness, tight spots and other imperfections left by upstream processes.

Sunnen states that: “Honing is an ideal replacement for hand-lapping barrel blanks before rifling. It quickly removes reamer scratches and surface waviness without labor-intensive hand lapping. By producing a consistent bore diameter (±0.0001″ or less), parallelism, roundness and surface finish end to end, honing yields more consistent performance from rifling buttons and cutters, resulting in a constant groove depth. The ideal bore geometry reduces distortion of the bullet shape.”

Barrel Bore honing cut-rifled rifling hammer forging accurateshooter.com

Computer-Controlled Bore-Honing
Honing can be done with great precision through the use of advanced, computer-controlled honing machines. Sunnen Products Company offers an advanced machine for .17 to .50-caliber barrels (see control panel below). The spindles on this machine can correct bore size imperfections so small only an air gauge can measure them. The consistency this allows improves bore uniformity, which, in turn, produces more accurate barrels for the precision market.

Barrel Bore honing cut-rifled rifling hammer forging accurateshooter.com

Barrel Bore honing cut-rifled rifling hammer forging accurateshooter.com

Sunnen Products Company is the world’s largest vertically-integrated manufacturer of honing systems, tooling, abrasives, coolants, and gauging for precision bore-sizing and finishing. Sunnen’s customers include manufacturers of diesel and gas engines, aerospace components, hydraulic components, oil field equipment, and gun/cannon barrels. Sunnen employs more than 600 people worldwide.

Permalink - Videos, Gear Review, Gunsmithing, Tech Tip 1 Comment »
April 11th, 2022

Online Barrel Weight Calculator for Various 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.

Permalink Gunsmithing, Tactical, Tech Tip No Comments »
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.

Permalink Gear Review, Gunsmithing, Tech Tip No Comments »
October 24th, 2019

Massive Fire Destroys Pac-Nor Barreling Plant in Oregon


A fire consuming the Pac-Nor Barreling Oregon factory was the lead story for the Curry Coastal Pilot.

The Pac-Nor Barreling production center in Oregon burned to the ground yesterday morning, October 23rd. The 7000-square-foot barrel-making facility located near Brookings, Oregon, was destroyed in a massive fire that apparently started with an electrical fault. There were nine workers in the facility at the time the fire broke out. All exited the building safely.

Millions of dollars of production machinery and barrels were lost in the fire. The Pac-Nor facility is insured, but Pac-Nor owner Chris Dichter said he was not sure if the plant would be re-built: “Thirty-five years of my life went up in this fire. I am 66 years-old and I don’t know if I have the time left. It took my lifetime to find all the machinery in this plant.”

UPDATE 10/26/19: Our Forum members contacted Pac-Nor and learned that the Dichters plan to rebuild the facility: “I got an e-mail from Kathy Dichter and she said six months to a year to rebuild, hopefully. She also said you could follow their progress on Facebook. That’s great news for the shooting community.”

The building and machinery inside were worth between four and six million dollars, Dichter estimated. There is insurance, but it is not clear whether Pac-Nor will resume production in the future.

How did the fire start? Chris Dichter said there were sparks when an electical conduit for a lathe was removed from a wall socket. Then when power was shut off from the main breaker, there was a blast of flame from the wall, almost like an explosion. Dichter declared: “I’d never seen anything go like that. It blew up with smoke and fire. It sounded like a tree fell on the plant.”

READ Full Pac-Nor Fire Report in Curry Coastal Pilot »

We recommend you read this story — it provides the most information on how the fire started. Pac-Nor owner Chris Dichter is quoted extensively.

Pac-Nor Fire Update with 11 Photos (Curry Coastal Pilot) »

This story has the most complete collection of Pac-Nor fire photos.

Del Norte Triplicate Report with Pac-Nor Fire Photos »

Early report with six Pac-Nor Fire photos.

Pac-Nor Barreling Inc., founded in 1985, was a major producer of precision rifle barrels in North America. Pac-Nor offered a huge variety of barrel lengths and contours, and had a vast selection of reamers for chamberings from .17 to .50 caliber. Pac-Nor was also well-known for its popular pre-chambered, “pre-fit” barrels. These provided affordable accuracy upgrades for factory rifles. This Editor has a Pac-Nor 3-groove 6mmBR pre-fit barrel that proved superbly accurate. That barrel, and the Savage rifle to which it was fitted, helped inspire this website, which started as 6mmBR.com.

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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 18th, 2019

PacNor Barrels Can Shoot — 1.240″ Group at 500 Yards Is Proof

6BR 6mmBR Preacher PacNor

You don’t hear much about PacNor barrels in long-range competition, but FORUM member Wes J (aka P1ZombieKiller), proved that they can shoot “lights-out” in a rig assembled by a talented gunsmith. A few seasons back, Wes decided to upgrade a 6mmBR for mid-range benchrest and varmint matches. Wes tells us: “Since I restocked my 6BR … I have not had a chance to shoot it much since I have been playing the 100-200 game. I decided to take it out and do some playing at 500 yards. I have to give some serious props to my buddy (and fellow FORUM member) ‘PREACHER’ who did the chambering and barrel work for me. He can certainly make a gun shoot good. The barrel is a PacNor 1:8″ twist. My load was 105gr Berger VLDs pushed by 29.6 grains of Varget.” The five-round, 500-yard group shot by Wes J with his 6BR, measured just 1.240″, as measured by OnTarget software. Now that’s one accurate rig!

Five by Five — 5-Shot Group at 500 Yards, 1.240″, 0.237 MOA
6BR 6mmBR Preacher PacNor

This Editor knows something about the potential of a PacNor barrel. I have a 3-groove stainless PacNor SuperMatch on a Savage-actioned 6BR. This barrel shoots honest quarter-MOA in calm conditions, and it cleans up super-easy. The interior finish is so good, I’ve never had to brush the bore or use abrasives, and after 750 rounds it shoots as well as ever. I attribute the easy cleaning to the fact the lands in a PacNor 3-groove are wide and flat, so they are gentle on bullet jackets. I think accuracy is helped by the fact that my PacNor runs on the tight side (0.236 land dimension) with a good amount of choke. That works well with the 105gr Lapua Scenars and 103gr Spencers I like to shoot. You can read more about my rifle, nick-named the “Poor Man’s Hammer”, in this Feature Article from our archives. On one particularly calm day, in the hands of my friend (and ace trigger-puller) Joe Friedrich, the Poor Mans’ Hammer put 3 shots in under 0.200″ (measured center to center) at TWO Hundred yards. If you get a good one, PacNor three-grooves can definitely shoot.

OnTarget SoftwareTarget Measurement with OnTarget Software
We used OnTarget software to measure the 5-shot group in the target above. This easy-to-use software is very repeatable, once you get a feel for plotting the shots. The latest On Target v2.25 Precision Calculator is FREE for a 15-day evaluation period. If you like it (and you will, trust us) there’s a modest $11.99 registration fee to activate the program. In addition to group size (in inches), OnTarget plots distance to aiming point, and the software automatically calculates the group’s vertical height, horizontal dispersion, average to center (ATC), and group size in MOA.

You can run a measurement on a scanned target or a photo of a target. You’ll need some known reference to set the scale correctly. The target above had a one-inch grid so it was easy to set the scale. Once you’ve set the scale and selected bullet diameter and target distance, you simply position the small circles over each bullet hole and the OnTarget software calculates everything automatically, displaying the data in a data box superimposed over the target image. To learn more about OnTarget Software, read AccurateShooter.com’s OnTarget Product Review. This article covers all the basics as well as some advanced “power user” tips. NOTE: Since the review was written, On Target has updated the software, and the free version now has a time limit.

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April 9th, 2019

Don’t Waste Time (and Ammo) on a Poor Factory Barrel

Savage Criterion BarrelIn our Shooters’ Forum, you’ll find a lengthy thread about accuracy problems with a Savage LRPV, chambered in 6mmBR. The gun would repeatedly split groups at 100 yards, and at 300 yards, the “flyers” would open up the groups to 1.5 MOA or larger. Interestingly, the factory test target (at right) showed a split group — not a good sign.

The gun’s owner, forum member LR_Shooter, tried a variety of tweaks: “I did this, done that… [changed] torque, tang floated, bedded action, recut chamber, and [adjusted firing pin]”. But nothing really helped. Frustrated, LR_Shooter asked his fellow Forum members for help. Much advice was proffered, including the novel idea of removing the middle action screw in the Savage 3-screw target action. Some of the advice proved helpful, but none of the suggested remedies produced a major improvement. This rifle, out of the box, tossed flyers and no amount of tweaking (or changes in shooting technique) really cured the basic problem. That is, until, the factory barrel got replaced…

Savage Criterion Barrel

New Criterion Pre-Fit Barrel Works Wonders
LR_Shooter acquired a Criterion pre-fit barrel from Jim Briggs at Northland Shooters Supply (NSS). These pre-fits are designed for easy installation with the standard Savage barrel nut. Wouldn’t you know it, with a new 30″ heavy-contour barrel on the LRPV, the gun started shooting way better. No more crazy fliers, no more split groups, no more excessive vertical. And the improvement came without any other major modifications.

LR_Shooter reports: “I got a replacement barrel from Jim at NSS. It is a 30″ bull Criterion barrel. So far, without playing with torque screws and having my old setup… I’m very satisfied with the barrel I got. Now I have no problem getting [groups] under 0.25 MOA. Finally this thing can shoot!”

Targets Shot with Savage LRPV Fitted with Criterion Barrel
Savage Criterion Barrel

The targets above, shot with the new Criterion barrel, speak for themselves. The left target was shot at 100 yards, while the target on the right was shot at 300 yards (very impressive).

Moral of the Story — Sometimes A New Barrel Really Is the Right Solution
All of us have struggled at times with a rifle that won’t live up to expectations. This Editor personally struggled for over a year with a .260 Rem Savage with a factory tube. The gun tended to split groups and the POI walked as the barrel heated. I tried one powder/primer combination after another, working through a variety of seating depths over many months. I was persistent. Out of stubbornness, I just believed that sooner or later I’d find the magic load.

Well folks, sometimes there’s really nothing you can do about a sub-par barrel. It is what it is. To really improve a gun’s accuracy (particularly a gun with a factory tube), you may need to open your wallet and get a quality aftermarket barrel. Spending months trying one recipe after another may simply be an overwhelming waste of powder, bullets, and your precious time.

Albert Einstein supposedly said: “Insanity is defined as doing the same thing over and over again, and expecting different results.” Well that sort of describes my efforts with my .260 Rem. Once I had enough evidence that my barrel split groups no matter what load combo (and seating depth) I tried, it was time to pony up for a new barrel. When I did finally screw on a nice PacNor 3-groove Supermatch, that Savage suddenly became a true tack-driver. As re-chambered in 6mmBR with the Pac-Nor, in calm conditions, my Savage will now consistently shoot in the twos with heavy bullets, and it can sometimes dip down into the ones with Berger 80gr flat-base bullets. The moral of the story here is simple — don’t waste weeks or months chasing your tail with a barrel that just won’t deliver (after a reasonable amount of testing). Save up for a custom barrel, get it chambered properly, and stop your cycle of frustration.

Contact Information for Northland Shooters Supply:
Northland Shooters Supply
10720 Rose Drive
Bismarck, ND 58503

Email: james@northlandshooterssupply.com
Website: Northlandshooterssupply.com
Telephone: (763) 682-4296; Fax: (763) 682-6098

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May 9th, 2017

High-Tech Honing — Major Advance in Barrel Making

Sunnen honing barrel hone CNC computer honer machine Pac-nor

Some custom barrel makers are now honing barrels (after drilling) to improve bore diameter uniformity, smooth the interior finish, and reduce barrel lapping times. For years, large-scale manufacturers of hammer-forged barrels have employed honing. Now the process is being used by smaller, “boutique” barrel-makers. This article explains how and why barrel honing is done. Take the time to watch the video. For anyone with an interest in barrel-making, this video is an eye-opener…

Barrel Honing Process Demonstrated (Worth Watching!):

Barrel Bore honing cut-rifled rifling hammer forging accurateshooter.com

For custom barrel makers, honing is a time-saver and cost cutter. A few minutes on a honing machine can cut lapping times in half, leaving a cross-hatched surface finish in single or low double-digit Ra. Honing is the same process used to make diesel fuel injectors with bore roundness and straightness controlled to fractions of a micron (<0.000040″), with surface finish Ra ≤0.15 µm (6 µin).

A key manufacturing process used for hammer-forged barrels is now getting attention from the makers of custom button-rifled barrels. This process is precision bore-honing. Honing produces a high-quality bore surface fast, which is critical to hammer forging. (Why is honing so important with hammer forging? Surface finish is the one feature of the barrel that cannot be controlled in hammer forging. Surface imperfections in a barrel blank tend to be amplified as the blank is formed on the rifling mandrel. And if the bore is chromed afterwards, imperfections in the surface finish become even more obvious.)

Honing dramatically improves bore diameter size uniformity and accuracy, surface finish and roundness throughout the length of the barrel. It can certainly be used in place of a pre-rifling lap. The chief difference between a lapped and honed bore is the direction of the finish lines in the bore. Honing leaves fine spiraling crosshatch lines, while a lap leaves lines going longitudinally in the bore. After rifling the manufacturer can remove the crosshatch finish with a quick lap if desired. Honing is fast, accurate, and can be automated. Its surface quality and geometry can duplicate lapping, except for the longitudinal lines of the lapped finish.

Frank Green of Bartlein Barrels told us: “We worked with Sunnen and we did all the initial testing on the prototype machine for them. The machine works great! We ordered and received last year a new manufactured machine with the changes we wanted on it and we just ordered a second one a month or so ago. Should be here next month.”

(more…)

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June 26th, 2016

Pre-Fit FIX — Savage Accuracy Improves with Criterion Barrel

Savage Criterion BarrelIn our Shooters’ Forum, you’ll find a lengthy thread about accuracy problems with a Savage LRPV, chambered in 6mmBR. The gun would repeatedly split groups at 100 yards, and at 300 yards, the “flyers” would open up the groups to 1.5 MOA or larger. Interestingly, the factory test target (at right) showed a split group — not a good sign.

The gun’s owner, forum member LR_Shooter, tried a variety of tweaks: “I did this, done that… [changed] torque, tang floated, bedded action, recut chamber, and [adjusted firing pin]”. But nothing really helped. Frustrated, LR_Shooter asked his fellow Forum members for help. Much advice was proffered, including the novel idea of removing the middle action screw in the Savage 3-screw target action. Some of the advice proved helpful, but none of the suggested remedies produced a major improvement. This rifle, out of the box, tossed flyers and no amount of tweaking (or changes in shooting technique) really cured the basic problem. That is, until, the factory barrel got replaced…

Savage Criterion Barrel

New Criterion Pre-Fit Barrel Works Wonders
LR_Shooter acquired a Criterion pre-fit barrel from Jim Briggs at Northland Shooters Supply (NSS). These pre-fits are designed for easy installation with the standard Savage barrel nut. Wouldn’t you know it, with a new 30″ heavy-contour barrel on the LRPV, the gun started shooting way better. No more crazy fliers, no more split groups, no more excessive vertical. And the improvement came without any other major modifications. LR_Shooter reports: “I got a replacement barrel from Jim at NSS. It is a 30″ bull Criterion barrel. So far, without playing with torque screws and having my old setup… I’m very satisfied with the barrel I got. Now I have no problem getting [groups] under 0.25 MOA. Finally this thing can shoot!” The targets below, shot with the new Criterion barrel, speak for themselves. The left target was shot at 100 yards, while the target on the right was shot at 300 yards (very impressive).

Targets Shot with Savage LRPV Fitted with Criterion Barrel
Savage Criterion Barrel

Read Thread on Savage Accuracy Issues Fixed By Criterion Barrel

Moral of the Story — Sometimes A New Barrel Really Is the Right Solution
All of us have struggled at times with a rifle that won’t live up to expectations. This Editor personally struggled for over a year with a .260 Rem Savage with a factory tube. The gun tended to split groups and the POI walked as the barrel heated. I tried one powder/primer combination after another, working through a variety of seating depths over many months. I was persistent. Out of stubbornness, I just believed that sooner or later I’d find the magic load.

Well folks, sometimes there’s really nothing you can do about a sub-par barrel. It is what it is. To really improve a gun’s accuracy (particularly a gun with a factory tube), you may need to open your wallet and get a quality aftermarket barrel. Spending months trying one recipe after another may simply be an overwhelming waste of powder, bullets, and your precious time.

Albert Einstein supposedly said: “Insanity is defined as doing the same thing over and over again, and expecting different results.” Well that sort of describes my efforts with my .260 Rem. Once I had enough evidence that my barrel split groups no matter what load combo (and seating depth) I tried, it was time to pony up for a new barrel. When I did finally screw on a nice PacNor 3-groove Supermatch, that Savage suddenly became a true tack-driver. As re-chambered in 6mmBR with the Pac-Nor, in calm conditions, my Savage will now consistently shoot in the twos with heavy bullets, and it can sometimes dip down into the ones with Berger 80gr flat-base bullets. The moral of the story here is simple — don’t waste weeks or months chasing your tail with a barrel that just won’t deliver (after a reasonable amount of testing). Save up for a custom barrel, get it chambered properly, and stop your cycle of frustration.

Contact Information for Northland Shooters Supply:
E-mail: briggs.j-b@q.com (that is Q.com not G.com)
Phone: (763) 682-4296
Fax: (763) 682-6098
Mailing address:
P.O. Box 333
Buffalo, MN 55313

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May 8th, 2016

Sunnen Barrel Honing System Used by Pac-Nor Barreling

Pac-Nor PacNor Barreling honing hone Sunnen lapping barrel
Pac-Nor Production Manager Casey Dichter says the Sunnen hone produces a consistency in bore diameter that is much superior to hand-lapping. The Sunnen machine has all but eliminated the standard pre-rifling lap. “You can really tell the difference between a bore that was honed before rifling and one that was [only] lapped”, notes Dichter.

Gun Barrel Honing System Hits Target for Pac-Nor Barreling
Manufacturing precision rifle barrels has always been something of an art that involves hand lapping of the bore surface twice, before and after the rifling profile is cut or swaged in by a rifling button. In fact, a bright, hand-lapped bore is considered one of the hallmarks of a precision rifle barrel, despite the inherent variations from manual work done by people who get bored and tired from the monotonous chore. Pac-Nor Barreling, Inc. set its sights on this issue more than a year ago and hit the X-ring with the newly developed Sunnen HTE honing machine. The machine has all but eliminated Pac-Nor’s pre-rifling lap, which is the more difficult and time-consuming of the two laps. Pac-Nor is also producing as many custom barrels as ever, but with a slightly smaller staff. “Our objectives with the hone were to build a better product with less labor, and the honing machine has exceeded my expectations,” said Pac-Nor Production Manager Casey Dichter. “The hone produces a consistency in bore diameter that is head and shoulders above lapping, within two to three millionths of an inch end-to-end when it’s really dialed in,” he said. “This, in turn, improves the consistency of the rifling process by minimizing variation in the depth of the grooves. We still finish lap after rifling, but it’s easier because we just polish off the fine crosshatch finish that may be left after honing and rifling.”

Pac-Nor PacNor Barreling honing hone Sunnen lapping barrel
The Sunnen hone secures the barrel blank in a 3-jaw chuck, with honing oil pumped into one end while the tool works from the opposite end. Sunnen’s specialized Long Bore Tool uses metal-bond diamond or CBN superabrasives to quickly remove reamer marks, waviness, tight spots and other imperfections left by upstream processes.

Honing is an ideal replacement for hand lapping barrel blanks before rifling. It quickly removes reamer scratches and surface waviness without labor-intensive hand lapping. A typical 600-grit abrasive can produce a 6-10 microinch Ra (0.15 to 0.25 µm) finish in a reamed barrel blank. By producing a consistent bore diameter (±0.0001″ or less), parallelism, roundness and surface finish end to end, honing yields more consistent performance from rifling buttons and cutters, resulting in a constant groove depth. The ideal bore geometry reduces distortion of the bullet shape.

Pac-Nor’s barrel-making process starts with cutting and facing premium bar stock, followed by gun drilling, done by four Pratt & Whitney twin-spindle machines and an Eldorado CNC twin spindle. After reaming, the barrels are gauged for size. Depending on the condition of the reamer, 0.0004″ to 0.0007″ of material is left in the bore. This must be manually lapped out or honed out to final size for rifling. “Everyone who works here has done hand-lapping,” said Dichter. “It’s an unpleasant job, particularly if the reamer is starting to get dull. Lapping may take 10 to 45 minutes, depending on the caliber of the barrel. We tried to shorten this, but when chatter marks get ‘ironed’ into the surface by the rifling button, the finish lap is even longer and more difficult, so there is no advantage. With lapping, too, there is potential for variation, simply because it’s a manual process. Lapping can also be a production limiter and in our region we have a very small labor force to draw on when we want to grow.”

Pac-Nor PacNor Barreling honing hone Sunnen lapping barrel
Pac-Nor cuts and faces premium bar stock, then gun drills on one of five twin-spindle machines, followed by reaming of the blanks. This rack of barrel blanks awaits completion.

The company had explored honing in the nineties, but re-visited the idea when Sunnen introduced its HTE honing machine in 2014. The HTE is a horizontal machine that can hone small-bore rifle barrels, with a diameter range of 0.150″ to 0.790” (4-20 mm), and lengths up to 60″ (1,524 mm). Designed specifically for long small bores, the machine features an extremely sensitive drive and tool feed system that provide maximum protection against tool overload/breakage. Tool specific force limits and run settings are stored in the touch-screen PC control, allowing the system to sense tight sections in the bore and correct them automatically.

Sunnen also developed a new Long-Bore Tool (LBT) designed to take on industry’s most difficult honing challenges in small bores of .17 caliber rifle barrels. The tool quickly remove reamer marks, waviness, tight spots and other imperfections left by upstream processes. The LBT utilizes metal-bond diamond or CBN super-abrasives for high productivity, long life and fast cycle times. Precision-machined of through-hardened tool steel, the LBT can produce bore accuracies of 0.000027″ (0.0006 mm) for diameter, roundness, and taper – from first part to last.

“We are currently honing about 80 percent of what we make and will do more as we acquire the tools in different calibers,” said Dichter. “Although there is a trade-off in cycle time and abrasive cost for additional honing, we are still able to run our reamers two to three times longer than when we lapped alone. With a hand lap, the time and effort increase when the reamer is getting dull.”

After honing, each barrel is inspected again before rifling with a pull-button. Pac-Nor makes its own Accu-Twist carbide rifling buttons and can provide different rifling styles, including polygonal, per the customer’s choice. A button is attached to a rod and the rod is pulled through the barrel. The company’s hydraulic rifling machine utilizes a CNC-machined twist bar with a helix angle that matches the twist rate requested by the customer. The final twist rate is confirmed afterward using a Barrel-Scan electro-optical twist measurement system.

The barrel is then stress-relieved in a tempering furnace, followed by contouring of the outer shape and final, finish lapping of the bore. “During the finish lap, you can really tell the difference between a bore that was honed before rifling and one that was lapped,” said Dichter. “You can easily sense any remaining tight or loose spots in the bore. The diameter uniformity and roundness of the honed bore are superb. The lap also feels different in a honed bore.”

Pac-Nor PacNor Barreling honing hone Sunnen lapping barrel

In competitive shooting where winning scores may be separated by thousandths of an inch, a few millionths of an inch improvement in the uniformity of a Pac-Nor barrel may make a big difference for a skilled shooter. For more information, visit www.sunnen.com or contact:

Sunnen Products Company
Mr. Bob Davis
Global Communications Mgr.
Sunnen Products Company
Tel: 314-781-2100
bdavis [at] sunnen.com

About Pac-Nor Barreling Inc.
Pac-Nor Barreling is a true custom manufacturer catering to bolt-action rifle shooters. The company’s principle markets are law enforcement, military, competitive shooters and hunters. Started in 1984 by avid shooter and company President Chris Dichter, Pac-Nor is now in its second generation under his son, Casey. In addition to barrel manufacturing, the shop will install the barrel on a customer’s action, or add features such as muzzle brakes or fluting on bolts and barrels etc.

The shop runs two shifts per day. A day shift of ten people produces 30-40 custom barrels of different calibers in 416R stainless or chrome-moly steel. A night shift of three people produces one type of barrel — about 50 AR-15 barrels per day for a rifle OEM.

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October 17th, 2015

Online Barrel Weight Calculator from Pac-Nor

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.

(more…)

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September 20th, 2014

Life Lesson: Every Barrel is Unique. Same Load Registers 4 Different Velocities in 4 Different Barrels

Put the same load in a variety of barrels (with the same length and chamberings) and you’ll see a wide variance in muzzle velocity. In fact, it’s not unusual to see up to 100 fps difference from one barrel to the next. We demonstrated this with a comparison test of Lapua factory ammo.

Chron Testing Lapua Factory Ammo
At our Southern California test range, we chronographed Lapua 105gr 6mmBR factory ammo in three different 8-twist barrels of similar length. The results were fascinating. Lapua specs this ammo at 2790 fps, based on Lapua’s testing with its own 26″ test barrel. We observed a speed variance of 67 fps based on tests with three aftermarket barrels.

barrel speed testing

Brand ‘S’ and Brand ‘PN’ were pre-fit barrels shot on Savage actions. Brand ‘K’ was fitted to a custom action. All test barrels were throated for the 100-108 grain bullets, though there may have been some slight variances in barrel freebore. With a COAL of 2.330″, the rounds were “jumping” to the rifling in all barrels. Among the four barrels, Brand ‘PN’ was the fastest at 2824 fps average — 67 fps faster than the slowest barrel. Roughly 10 fps can be attributed to the slightly longer length (27″ vs. 26″), but otherwise this particular barrel was simply faster than the rest. (Click Here for results of 6mmBR Barrel Length Velocity Test).

Results Are Barrel-Specific, Not Brand-Specific
These tests demonstrate that the exact same load can perform very differently in different barrels. We aren’t publishing the barrel-makers’ names, because it would be wrong to assume that ‘Brand X’ is always going to be faster than ‘Brand Y’ based on test results from a single barrel. In fact, velocities can vary up to 100 fps with two identical-spec barrels from the SAME manufacturer. That’s right, you can have two 8-twist, 26″ barrels, with the same land-groove configuration and contour, from the same manufacturer, and one can be much faster than another.

Don’t Demand More Than Your Barrel Can Deliver
We often hear guys lament, “I don’t get it… how can you guys get 2900 fps with your 6BRs and I can only get 2840?” The answer may simply be that the barrel is slower than average. If you have a slow barrel, you can try using more powder, but there is a good chance it may never run as fast as an inherently fast barrel. You shouldn’t knock yourself out (and over-stress your brass) trying to duplicate the velocities someone else may be getting. You need to work within the limits of your barrel.

Factory Ammo Provides a Benchmark
If you have a .223 Rem, 6BR, .243 Win, 6.5×47 Lapua, 6.5×55, .308 Win, 30-06, or 300 WM Rifle, we recommend you buy a box of Lapua factory-loaded ammo. This stuff will shoot great (typically around half-MOA), and it can give you a baseline to determine how your barrel stacks up speedwise. When you complete a new 6BR rifle, it’s wise to get a box of the factory ammo and chronograph it. That will immediately give you a good idea whether you have a slow, average, or fast barrel. Then you can set your velocity goals accordingly. For example, if the factory 6BR ammo runs about 2780-2790 fps in your gun, it has an average barrel. If it runs 2820+ in a 26″ barrel (or 2835 fps in a 28″), you’ve got a fast tube.

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