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 11th, 2019

Velocity Test with Four Different Barrels — Surprising Results

barrel speed testing

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 some years ago, 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 Velocity Variance
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).

IMPORTANT: 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, 6mmBR, .243 Win, 6.5×47 Lapua, 6.5 Creedmoor, 6.5×55, .308 Win, 30-06, or .338 LM 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. [Editor’s NOTE: The original test was conducted in 2008. The velocity of current-production Lapua factory ammo might be higher or lower, so your results may vary.]

When you complete a new 6mmBR rifle, it’s definitely smart 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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November 26th, 2017

Half-MOA Handgun — 6mm BR Savage Striker Pistol

Savage Striker pistol 6mmBR 6BR

Here’s something you’ve probably never seen before — a single-shot, bolt-action pistol chambered for the 6mm BR Norma cartridge. Featured as one of our Guns of the Week a while back, this Green Machine is a Savage Striker upgraded by Chuck G. from Arizona, a self-described “Savage Maniac”.

Chuck transformed this Savage Striker single-shot from a ho-hum .308 into a reliable half-MOA precision 6BR that can run with accurized rifles all the way out to impressively long ranges. Here we provide highlights from our original article. Click the link below to read our full Savage Striker article, which is three times longer than this story, and has more photos, plus videos and a detailed load development section.

READ Full Savage Striker 6mm BR Gun of the Week Story »

The Striker Project — Pursuit of Precision, by Chuck G.
I didn’t even know Savage Strikers existed until I saw one for sale on Gunbroker.com. I snagged it with a $400 bid. My idea was to build an accurate, long-range pistol on a pauper’s budget. As purchased, the Striker had a .308 barrel with an unknown round count, the standard center-grip, black synthetic stock, an odd two-piece custom brake, and an old Burris 4X pistol scope in a Conetrol 2-piece ring set. The trigger was very heavy, 6-8 lbs I’d estimate, with a lot of take-up and over-travel.

Initial Disappointments — Too Much Recoil, Poor Accuracy
My initial attempts to get the Striker to shoot well at even 100 yards were disappointing. I was never able to get better than a 3″, 5-shot group at 100. Not what I was looking for. Being used to benchrest triggers, the pull on this one was hard for me to manage. The gun would roll around on any type of front rest I had, and from a cement bench on a bipod it would jump about 18 inches up and sideways with every round. Not being used to this type of gun, I found the recoil and muzzle blast to be unsettling. It was hard not to flinch. I started off using my 1K .308 rifle load, 175 SMKs over 44 grains of Varget. That probably would have knocked the hell out of a deer, but it wasn’t much fun to shoot from the bench.

Savage Striker Pistol 6mm BR 6BR

New Caliber, New Barrel — Way Better Accuracy!
I decided to rebuild the Striker in a caliber that would be more fun to shoot. 6mmBR was an obvious choice for all the usual reasons–good brass, wide choice of match bullets, easy to load, low recoil, very accurate, and relatively cheap to shoot. As part of a SavageShooters.com group buy, I ordered a 15″, SS match grade, 3-groove, heavy varmint contour, 10-twist barrel from Pac-Nor. To set the freebore, I provided Pac-Nor with a dummy case with an 88gr LD Berger bullet seated to use as a guide. Total delivered price was $340 chambered and threaded for a muzzle brake from JP Rifles.

Savage Striker 6mmBR 6BR PacNor

When I bought it, the Striker, with factory .308 barrel, shot 3″ groups at 100. Now, with a Pac-Nor 6BR Match barrel, 3″ fore-arm plate, upgraded trigger, 24X scope, and match bullets, the gun consistently groups 1/2″ or better at 100 yards. What a transformation!”

Striker Project — Mission Accomplished
With further load development and bench practice, the gun is showing even more accuracy potential. Using a 24X target scope, the Striker has delivered 5-shot groups in the 3s and 4s during recent range visits. All in all, I’m very satisfied with the project. I ended up with an accurate, fun-to-shoot gun for under $1,000 including scope, paint, and bedding materials.

Savage Striker 6BR 6mm BR Norma

Stock Modifications
While waiting for the barrel I started working on the stock. As virtually no aftermarket stocks were readily available for the center-grip Striker, I decided to rebuild the standard black synthetic stock. The grip fit my hand poorly so I worked it over with a Dremel tool and sandpaper, built up the grip with Bondo, filled in some holes and bedded the action using Devcon Plastic Steel. This was my very first attempt at these tasks so progress was slow. Once I had re-shaped the stock, I sprayed five coats of “John Deere” green topped by several coats of auto clear. It came out surprisingly well considering I had never painted a stock before. I had originally planned to build up the fore-end to 3″ wide using Bondo but later decided to just use a Sinclair Benchrest Adapter that I had on hand.

Savage Striker 6BR 6mmBR

Chuck notes: “I’m really pleased with the C & J one-piece Rest. It’s solid, heavy, and well-designed. There is no real need for a windage top; small adjustments are easily made by slightly shifting the pistol butt. Elevation adjustments are positive and once the pistol is set up on this rest NOTHING moves.”

READ Full Savage Striker Gun of the Week Story »

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June 9th, 2012

6BR Shines at 500 Yards with PacNor Barrel

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. Wes tells us: “Since I restocked my 6BR more than a year ago, I have not had a chance to shoot it much since I have been playing the 100-200 game. Well, last week 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!

6BR PacNor

6BR PacNor

This Editor knows something about the potential of a PacNor barrel. I have a 3-groove stainless PacNor SuperMatch on my trusty Savage-actioned 6BR. This barrel shoots quarter-MOA or better 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 PacNors run 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. In its last outing 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 basic version 1.10 of OnTarget is FREE, while there’s a modest $11.99 registration fee for version 2.10. 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.

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