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July 29th, 2021
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.
This is a very useful test is you’re thinking about building a .308 Win hunting rifle, or perhaps thinking of going shorter for your F-TR rifle to save weight.
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 FPS 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, 2021
Most of us own a .223 Rem rifle. Now, thanks to our friends at Rifleshooter.com we can assess exactly how velocity changes with barrel length for this popular cartridge.
Rifleshooter.com performed an interesting test, cutting the barrel of a .223 Rem rifle from 26″ 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 .223 Rem/5.56 ammo were chron’d at each barrel length. The Rifleshooter.com team that conducts these tests has a full-service gun shop, 782 Custom Gunworks — visit 782guns.com.
READ RifleShooter.com 5.56/.223 Barrel Cut-Down Test Article »
Test Barrel Lost 25.34 FPS Per Inch (.223 Rem Chambering)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. The average speed loss of the four types of .223/5.56 ammo, with a 9.5″ shortening of barrel length, was 240.75 fps total (from start to finish). That works out to an average loss of 25.34 fps per inch.
| 5.56/.223 Barrel Cut-Down Speed Test 26″ to 16.5″ |
Start FPS at 26″ |
End FPS at 16.5″ |
Total Loss |
Average Loss Per Inch |
| UMC .223 55gr |
3182* |
2968 |
214 |
22.5 FPS |
| Federal M193 55gr |
3431 |
3187 |
244 |
25.7 FPS |
| Win m855 62gr |
3280 |
2992 |
288 |
30.3 FPS |
| Blk Hills .223 68gr |
2849 |
2632 |
217 |
22.8 FPS |
*There may have been an error. The 25″ velocity was higher at 3221 fps.
Rifleshooter.com observed: “Cutting the barrel from 26″ to 16.5″ resulted in a velocity reduction of 214 ft/sec with the UMC 223 55-grain cartridge, 244 ft/sec with the Federal M-193 cartridge, 288 ft/sec with the Winchester M855 cartridge and 217 ft/sec with the Back Hills 223 68-grain match cartridge.”
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. 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 45.7° F.”
CLICK HERE to Read the Rifleshooter.com Test. This includes detailed charts with inch-by-inch velocity numbers.
See More Barrel Cut-Down Tests on Rifleshooter.com
Rifleshooter.com has performed barrel cut-down tests for many other calibers/chamberings including 6mm Creedmoor, .308 Winchester, and .338 Lapua Magnum. See these test results at Rifleshooter.com.
Much Different Results with 6mmBR and a Longer Barrel
The results from Rifleshooter.com’s .223/5.56 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 longer than Rifleshooter.com’s .223 Rem start length. Velocity loss may be more extreme with shorter barrel lengths. And, of course, different cartridge types and powder/bullet combinations will yield different results.
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February 17th, 2021
 You may have heard the phrase “blueprinting an action”, but do you know what that really means? Do you know what operations are done to an action during the blueprinting process? To help you understand, gunsmith Bill Marr of RifleShooter.com has created a helpful article showing a Rem 700 blueprinting job start to finish. This article spotlights how the procedures can be done with manual tools. Bill, who runs 782 Custom Gunworks Ltd., can also perform many of these operations with modern automated machinery. In fact, Bill has written a follow-up article on Truing a Rem 700 receiver with a Lathe.
Bill explains: “Blue-printing, or truing a rifle action, ensures the receiver face, threads, lugs, bolt lugs, and bolt face are square to the center line of the receiver.” In Bill’s informative article, Bill shows how he blueprints a Remington 700 short action receiver with .308 Win bolt face. He covers the following procedures step by step:
Action Disassembly
Ream Minor Diameter of Receiver Threads
Square the Receiver Lugs
Square the Face of the Receiver
Lap the Bolt Lugs
Square the Bolt Face
Bill employed a variety of tools from Brownells to complete the blueprinting job, including: Remington 700 Armorer’s Kit; Manson Receiver Accurizing Kit; Bolt Lapping Kit; Bolt Face Truing Tool; Manson Receiver Ring Facing Cutter; Multi-Vise with Jaw Pads; Silicone Carbide Abrasive; and Do-Drill Cutting Oil.
Highlights from the Rifleshooter.com article:
1. Chasing the Threads
We use the bushings to guide the receiver tap. This chases the threads and ensures they are square.
2. Truing the Receiver Face
Using the receiver facing tool, the front of the receiver is trued. The tool is placed over the tap and turned by hand. We used Do Drill to lubricate it.
3. Lapping the Lugs
The bolt lapping tool screws into the front of the action and applies rearward pressure on the bolt face. A little bit of lapping compound is placed on the front of the receiver lugs. The bolt handle is then raised and lowered repeatedly. Note — it is critical that we do not get any lapping compound on any other surfaces.
4. Truing the Bolt Face
On this bolt, the central part of the bolt face was low. After the truing operation, this Rem 700 bolt face is now completely square to the action.
IMPORTANT: Rifleshooter.com states: “This article highlights our project and is presented for information purposes only. This provides an overview of the process and should not be attempted without the guidance and supervision of an experienced gunsmith“.
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November 14th, 2020
Rifleshooter.com built this tactical rifle (top image) with a Howa 1500 action, Shilen barrel, and MDT chassis. Below is a factory Howa 1500 Multi-Cam rifle.
Many of our readers are thinking of purchasing a Howa rifle or barreled action. These feature smooth-running actions with a good two-stage HACT trigger. But some folks have heard that it may be difficult to find stocks, or to fit an after-market barrel. That’s not true. There are many stock options available, and in this article, Bill of RifleShooter.com shows that it is easy to remove the factory-installed barrel with the right tools. We think a Howa makes a fine basis for a varmint rig or field rifle. Or you can build a tactical rifle as Bill did. You can start with the factory barrel and when you want/need more accuracy, then have a gunsmith install a custom barrel from Krieger, Shilen, or other quality brand.
What You Need to Know About Howa 1500-series Rifles
Tech Feature by RifleShooter.com
Consider this article the “Howa 1500 Overview”. AccurateShooter.com’s editor mentioned there’s been a lot of interest in Howa rifles and barreled actions imported by Legacy Sports International. In addition to being able to buy a complete rifle from a dealer, Brownells sells barreled actions in a wide variety of calibers and configurations. In this post we are going to take a look at the Howa 1500 series.
Howa Rifles — General Background
Howa is a Japanese heavy machinery company. One of its product lines are firearms, which, are imported into the United States of America by two different companies, Legacy Sports International and Weatherby. Legacy sells the 1500 under the manufacturers name while Weatherby re-brands the guns as the Weatherby Vanguard. In general, the finishes on the Weatherby rifles are more refined than the LSI-imported 1500s.
General Evaluation of Howa 1500 Rifles
I’ve found Howa 1500s to be solid, entry-level rifles that are capable of sub-MOA accuracy out of the box. I’ve actually purchased two Howa rifles I’ve tested because I like them so much. The gun below, a Howa Mini-Action in 7.62×39 Russian, is one of my favorite factory guns to shoot. I’m running a Tract Optics Toric on it, these are solid little rifle scopes that offer great performance for the money.
Check out this three-shot group I drilled at 100 yards with the rifle above and 125-grain Sierras. It took a lot of work and load development to get there, but when it did, it worked well.
 Howa 1500 HACT 2-Stage Trigger
Howa 1500s feature the very nice Howa HACT trigger. This is an adjustable, two-stage trigger, set for about 3 pounds (combined stages). Crisp and repeatable, this is an excellent trigger for a factory gun. There is no annoying Glock-style safety lever in the middle of the trigger blade. The 2-stage design and pull weight range works well for a hunting rifle or a rig for PRS competition. Rifleshooter.com says the Howa trigger is “one of the best factory triggers, along with Tikka. I’ve found the Howa trigger superior to a Remington 700 — the Howas doesn’t need to be replaced.”
Writing for the Western Outdoor News, WONews.com, Steve Comus has field-tested the new HACT Trigger. Steve writes: “I always liked two-stage triggers, because of the way I could take-up the slack and then actually know when the rifle was going to go off. The take-up on the [HACT] trigger was fast and easy. The crisp, positive release when pressure was put on during the second stage [reminded me] of some of the target rifles I shot through the years.”
Howa Actions — Three Options
Howa offers three action lengths: Mini, Short, and Long. You can see the bolts for the three action lengths in the image below. The Mini-Action has similar external dimensions to the Remington Model Seven, however, the Mini-Action’s bolt does not travel as far to the rear. This is a mixed bag. The upside is you have a quicker action (shorter bolt throw). The downside is you are limited to shorter rounds such as the .223 Remington, 7.62×39mm Russian, and 6.5 Grendel. But if you need a bigger cartridge, just choose the standard or long action Howa variant.
Howa 1500 vs. Remington 700 — Important Differences
Is the Howa 1500 a Remington 700 clone, or some kind of improved Remington 700? No, not really. While the top radius of the Howa 1500 does match the Model 700, and they can both use the same two-piece scope bases, there are a number of differences.
If you look at the Howa 1500 alongside the Remington 700 you’ll note the M700 is a round action, while the Howa is a flat-bottom action. In many ways the Howa’s bottom half reminds me of a push-feed Winchester. This means the chassis and stocks that support a Howa 1500 are not V-block based like you’ll find on a 700, instead they have a flat bottom. While the bolt of the Howa is similar in external appearance to the Model 700, it does offer some improvements, notably an M16-style extractor and a firing pin assembly that can be easily removed without tools.
Howa 1500 action screws are metric and are in a different location from the 700. The Howa 1500 has an integral recoil lug that accepts the front action screw, this means you have more of the front action screw engaging the action. WARNING: If you install it into a poorly-fitted stock or action you may bind it.
Can a Howa Action Be Used for a Custom Rifle Project?
Absolutely! You can either buy a barreled action from Brownells and throw it in a chassis system/stock of your choice or you can use a stripped action to build a custom rifle. If you are in the chassis market, MDT offers a wide variety of chassis in different price ranges. All have worked well for me.
How to Remove Howa Factory Barrel from Action
You may have heard internet grumblings about removing Howa barrels. Some keyboard commandos say they are extremely difficult to remove without a relief cut. Well Bill at Rifleshooter.com demonstrates that Howa barrels can be removed without trouble, provided you have the right tools. Watch this video:
Watch Howa Barrel Removal Video — Quick and Easy (Click Speaker Icon for Audio)
Q: Is it difficult to remove a barrel from a Howa 1500?
A: Not very. I’ve heard from some smiths that worked on Howas (years ago) that the factory barrels are difficult to remove. However of the half dozen or so Howa barrels that I’ve pulled, they’ve been very easy. I use a Brownells action wrench with the top piece for a Rem Model 700 and the flat bottom resting against the flat on the wrench.
Howa Actions Require Metric Barrel Threads
It’s easy to thread a barrel for a Howa Action. You just have to cut metric threads — most lathes out there can cut them. I cut the threads below on a manual lathe using change gears. [Editor: John Whidden cuts metric tenon threads with a CNC lathe. “It’s easy,” John tells us, “No issue whatsoever.”]
Using Howa Actions for Custom Rifles
I have built a few customs with Howa actions. Below is one of my favorite, a .308 Winchester. It consists of a Howa 1500 action, Shilen Select Match Remington Varmint contour barrel, and Modular Driven Technologies (MDT) ESS chassis. Great rifle and it hammers!
To learn more about Howa rifles and actions, visit Legacy Sports International. To buy a Howa barreled action, visit Brownells.com.
To learn more about modular chassis systems for Howa rifles, visit MDTTAC.com
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February 22nd, 2020
 Velocity vs. barrel length — How much speed will I sacrifice with a shorter barrel? Hunters and competition shooters often ask that. Today we DO have solid answers to that question for many cartridge types thanks to Rifleshooter.com.
Rifleshooter.com has conducted a series of barrel cut-down tests for many popular chamberings: .223 Rem, 6mm Creedmoor, .243 Win, 6.5 Creedmoor, .308 Win, .300 Win Mag, .338 Lapua Magnum and more. And recently Rifleshooter.com added the new .224 Valkyrie cartridge to the list, cutting a 28″ Shilen barrel down to 16.5″ in one-inch increments. Rifleshooter.com measured the .224 Valkyrie’s velocities at each barrel length with four different types of factory ammo.
For its .224 Valkyrie test, RifleShooter.com sourced a Shilen Match Barrel and fitted it to a Rem 700 short action employing a one-piece PT&G bolt with the required .440″ (SPC-sized) bolt-face. The barreled action rides in a MDT LSS-XL Gen 2 Chassis.
Bill, Rifleshooter.com’s Editor, explained his test procedure:
“I gathered four different types of factory Federal 224 Valkyrie ammunition, the 90gr Sierra MatchKing (SMK), 90gr Fusion soft point (SP) (referred to a Fusion MSR), 75gr Total Metal Jacket (TMJ) and 60gr Nosler Ballistic Tip Varmint (NBT). After a brief barrel break in and zero, I fired 5 rounds of each cartridge at each barrel length (except the 75 TMJ, I fired 4 rounds at each barrel length due to limited resources). I recorded the average muzzle velocity and standard deviation for each ammunition and barrel length combination and cut the barrel back 1 inch and repeated the process. I recorded barrel lengths from 28″ to 16.5″ (I try to save these barrels as finished 16″ tubes so they don’t go to waste).”
The Heavy Bullet 90gr Ammo Lost about 21 FPS per Inch
How did the test turn out? You’ll find all the results summarized in helpful tables with inch-by-inch velocity and SD numbers. For the two, 90gr ammo samples, results were similar. The 90gr SMK ammo started at 2782 fps (28″), finishing at 2541 fps (16.5″). That’s a loss of 241 fps, or 20.96 fps average per inch of length. The ammo loaded with 90gr Fusion SPs started at 2797 fps (28″) and ended at 2561 fps (16.5″), a drop of 236 fps. That’s 20.5 fps loss per inch. NOTE: Ambient temperature during the test was 45° F. You could expect the overall velocities to be a bit higher during hotter summer months.
See 90gr SMK Velocity/Length Test Chart | See 90gr Fusion SP Velocity/Length Test Chart
With a the smaller bullets, the effect was even more dramatic. As you’d expect they started out faster. The ammo with 60gr Nosler Ballistic Tips (NBT), a good choice for varminters, started at 3395 fps (28″), and declined to 3065 fps (16.5), a total velocity drop of 330 fps. Average velocity loss was 28.7 fps per inch of barrel length. Rifleshooter.com also tested Federal 75gr TMJ ammo.
About the .224 Valkyrie Cartridge
The new .224 Valkyrie was introduced late last year as a Hot Rod cartridge that will work in AR15s. Designed to rival the .22 Nosler while still running well in ARs, the new .224 Valkyrie offers excellent long-range performance when loaded with modern, high-BC bullets. We expect some bolt-action PRS shooters might adopt the .224 Valkyrie. Why? Reduced recoil. With the 90gr SMK, the .224 Valkyrie offers ballistics similar to the 6.5 Creedmoor but with significantly less felt recoil. Check out this chart from Federal showing comparative recoil levels:
.224 Valkyrie vs. .22-250 Remington
The Social Regressive explains: “There are two key reasons why the .224 Valkyrie is unique and desirable. First, it is specifically designed to fit the limitations of the AR-15 platform. It does so even when loaded with gigantic bullets, like the 90-grain SMK that Federal announced. The .22-250 Rem is too long and too fat to work in the AR-15 platform; it needs an AR-10 bolt and magazine.”
 Image from Social Regressive .224 Valkyrie Youtube Video.
The new .224 Valkyrie is basically a 6.8 SPC case necked down to .22-caliber. You can use your existing AR15 lower, but you will need a dedicated .224-Valkyrie upper, or at the minimum a new barrel, modified bolt with proper bolt face, and 6.8-compliant mags.
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October 31st, 2019
Most of us own a .223 Rem rifle. Now, thanks to our friends at Rifleshooter.com we can assess exactly how velocity changes with barrel length for this popular cartridge.
Rifleshooter.com performed an interesting test, cutting the barrel of a .223 Rem rifle from 26″ 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 .223 Rem/5.56 ammo were chron’d at each barrel length. The Rifleshooter.com team that conducts these tests has a full-service gun shop, 782 Custom Gunworks — visit 782guns.com.
READ RifleShooter.com 5.56/.223 Barrel Cut-Down Test Article.
Test Barrel Lost 25.34 FPS Per Inch (.223 Rem Chambering)
How much velocity do you think was lost, on average, for each 1″ reduction in barrel length? The answer may surprise you. The average speed loss of the four types of .223/5.56 ammo, with a 9.5″ shortening of barrel length, was 240.75 fps total (from start to finish). That works out to an average loss of 25.34 fps per inch.
| 5.56/.223 Barrel Cut-Down Speed Test 26″ to 16.5″ |
Start FPS at 26″ |
End FPS at 16.5″ |
Total Loss |
Average Loss Per Inch |
| UMC .223 55gr |
3182* |
2968 |
214 |
22.5 FPS |
| Federal M193 55gr |
3431 |
3187 |
244 |
25.7 FPS |
| Win m855 62gr |
3280 |
2992 |
288 |
30.3 FPS |
| Blk Hills .223 68gr |
2849 |
2632 |
217 |
22.8 FPS |
*There may have been an error. The 25″ velocity was higher at 3221 fps.
Rifleshooter.com observed: “Cutting the barrel from 26″ to 16.5″ resulted in a velocity reduction of 214 ft/sec with the UMC 223 55-grain cartridge, 244 ft/sec with the Federal M-193 cartridge, 288 ft/sec with the Winchester M855 cartridge and 217 ft/sec with the Back Hills 223 68-grain match cartridge.”
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. 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 45.7° F.”
CLICK HERE to Read the Rifleshooter.com Test. This includes detailed charts with inch-by-inch velocity numbers.
See More Barrel Cut-Down Tests on Rifleshooter.com
Rifleshooter.com has performed barrel cut-down tests for many other calibers/chamberings including 6mm Creedmoor, .308 Winchester, and .338 Lapua Magnum. See these test results at Rifleshooter.com.
Much Different Results with 6mmBR and a Longer Barrel
The results from Rifleshooter.com’s .223/5.56 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 longer than Rifleshooter.com’s .223 Rem start length. Velocity loss may be more extreme with shorter barrel lengths. And, of course, different cartridge types and powder/bullet combinations will yield different results.
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August 27th, 2019
With Randy Wise’s recent record-setting ELR performance with a .338 Lapua Magnum Savage rifle, we thought our readers might be interested in a .338 LM velocity test conducted by our friend Bill Marr, Editor of Rifleshooter.com.
A couple seasons back, Bill did a fascinating barrel cut-down test on a .338 Lapua Magnum rifle. Bill, a skilled gunsmith who runs 782 Custom Gunworks, cut down the barrel from 30″ to 17″ in one-inch increments. During the cut-down process, Marr measured velocities at each barrel length, shooting four rounds after each cut. As you’d expect, there was a huge change in velocity from long to short. Speeds were measured at the muzzle with a Magnetospeed barrel-mounted chronograph.
If you’re looking for max velocity with the .338 LM, go long. With 250-grain Sierra MK bullets, the peak velocity Bill measured was 2942 FPS at the full, 30-inch length. This decreased pretty steadily down to 2547 GPS at the shortest 17″ length. That’s an average decrease of 30.4 FPS per inch from 30″ to 17″.
Bill also tested 300-grain Sierra MatchKings. This is interesting because Randy Wise ran 300-grain bullets (Berger Hybrids) in a 26″ factory barrel for his ELR record. Peak velocity was 2833 FPS at 30″, 2799 FPS at 26″, and 2492 FPS at the shortest 17″ length. Interestingly, velocity at 29″ was higher than at 30″ for the 300-grainers. Bill notes: “The 300 SMK load showed a slight increase from 30 to 29″. I’ve recorded this in other tests and it seems to be more common with a heavier load. I suspect it is primarily due to the small sample sizes being used along with the relative proximity of muzzle velocities in adjacent lengths.”
At each new (shorter) barrel length, velocity was measured with a MagnetoSpeed chronograph using two different loads, 250gr SMKs with H4831sc and 300gr SMKs with Retumbo. Four shots were fired at each length with each load, a total of 112 rounds.
Load #1: 250gr Sierra MK, Lapua brass, CCI #250 primer, H4831SC, OAL 3.720″.
Load #2: 300gr Sierra MK, Lapua brass, Win WLRM primer, Retumbo, OAL 3.720″.
.338 LM Barrel Cut-Down Test Results Summary
.338 Lapua Magnum with 250gr Sierra MatchKings
After shortening the barrel from 30″ to 17″, total velocity reduction for the 250-grainers was 395 FPS, an average loss of 30.4 FPS per 1″ cut. The amount of velocity loss per inch rose as the barrel got shorter, with the biggest speed reduction, a loss of 55 FPS, coming with the cut from 18″ to 17″.
Start Velocity: 2942 FPS | End Velocity: 2547 FPS | Average Loss Per Inch: 30.4 FPS
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August 17th, 2019
You may have heard the phrase “blueprinting an action”, but do you know what that really means? Do you know what operations are done to an action during the blueprinting process? To help you understand, gunsmith Bill Marr of RifleShooter.com has created a helpful article showing a Rem 700 blueprinting job start to finish. This article spotlights how the procedures can be done with manual tools. Bill, who runs 782 Custom Gunworks Ltd., can also perform many of these operations with modern automated machinery. In fact, Bill has written a follow-up article on Truing a Rem 700 receiver with a Lathe.
Bill explains: “Blue-printing, or truing a rifle action, ensures the receiver face, threads, lugs, bolt lugs, and bolt face are square to the center line of the receiver.” In Bill’s informative article, Bill shows how he blueprints a Remington 700 short action receiver with .308 Win bolt face. He covers the following procedures step by step:
Action Disassembly
Ream Minor Diameter of Receiver Threads
Square the Receiver Lugs
Square the Face of the Receiver
Lap the Bolt Lugs
Square the Bolt Face
Bill employed a variety of tools from Brownells to complete the blueprinting job, including: Remington 700 Armorer’s Kit; Manson Receiver Accurizing Kit; Bolt Lapping Kit; Bolt Face Truing Tool; Manson Receiver Ring Facing Cutter; Multi-Vise with Jaw Pads; Silicone Carbide Abrasive; and Do-Drill Cutting Oil.
Highlights from the Rifleshooter.com article:
1. Chasing the Threads
We use the bushings to guide the receiver tap. This chases the threads and ensures they are square.
2. Truing the Receiver Face
Using the receiver facing tool, the front of the receiver is trued. The tool is placed over the tap and turned by hand. We used Do Drill to lubricate it.
3. Lapping the Lugs
The bolt lapping tool screws into the front of the action and applies rearward pressure on the bolt face. A little bit of lapping compound is placed on the front of the receiver lugs. The bolt handle is then raised and lowered repeatedly. Note — it is critical that we do not get any lapping compound on any other surfaces.
4. Truing the Bolt Face
On this bolt, the central part of the bolt face was low. After the truing operation, this Rem 700 bolt face is now completely square to the action.
IMPORTANT: Rifleshooter.com states: “This article highlights our project and is presented for information purposes only. This provides an overview of the process and should not be attempted without the guidance and supervision of an experienced gunsmith“.
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May 7th, 2019
Our friend Bill Marr of Rifleshooter.com has done it again — conducted a fascinating 6mm Creedmoor barrel cut-down test that reveals how velocity changes with barrel length. This time Bill started with a 24″ Proof Research stainless steel barrel on a Howa action. Bill says this was a well-used barrel, with over 1800 rounds through it. So, the velocities might be a bit different than a new barrel of similar length. Bill cut the barrel down in one-inch increments. Here are some results from the test:
24″ Velocity: 2893 FPS | 20″ Velocity: 2755 FPS | 16.1″ Velocity: 2598 FPS
 For this latest test, Rifleshooter cut the barrel in one-inch increments from 24″ to 16.1″ (just over legal minimum). Velocities were measured with a MagnetoSpeed V3 chronograph mounted on arm attached to the stock. This allowed the chrono to be adjusted inwards as the barrel was cut shorter, inch by inch.
For the 6mm Creedmoor cartridge, Bill loaded Hornady 108gr ELD Match bullets over 41.5 grains of Hodgdon H4350 with CCI 200 primers in new Starline brass.
The results were interesting to say the least. Bill reports: “Muzzle velocities ranged from 2,893 ft/sec at 24″ to 2,598 ft/sec at 16″ for a decrease in muzzle velocity of 295 ft/sec. Muzzle velocity changes per inch of barrel length ranged from 6 ft/sec per inch between 20 and 19 inches to 63 ft/sec per inch between 19 and 18 inches. Average velocity change per inch of barrel length was 37.9 ft/sec.”
Bill concludes: “An average drop of 37.9 ft/sec/inch of barrel is fairly significant and is what would be expected with a fast moving 6mm cartridge like the 6mm Creedmoor. While I’m used to seeing 6mm Creedmoors with slightly longer barrel lengths than 24″, when coupled with a sound suppressor the additional length can make moving the rifle quickly more difficult.
I’d suggest staying with longer barrel lengths wherever possible with this cartridge. At shorter lengths, it does give up more performance than its big brother the 6.5 Creedmoor.”
More 6mm Creedmoor Velocity Data from 2017 Cut-Down Test
If you’re curious about 6mm Creedmoor velocities at longer barrel lengths, back in 2017 Rifleshooter completed a 6mm Creedmoor barrel cut-down test from 31 inches all the way down to 17 inches. The test included four bullet types from 95 grains to 110 grains. With the 110gr Sierra MK, velocity at 31″ was an impressive 3110 fps. Surprisingly the velocity didn’t decrease that much for the first few inches. Even at 26″ (a five-inch reduction), measured velocity with the 110s was 3073 fps, a loss of 7.4 fps per inch on average. With a barrel shortened all the way to 20″ however, velocity had dropped down to 2949 fps, a significant (161 fps) loss. CLICK HERE for complete results from that 31″-17″ Barrel Cut-Down Test.
CLICK HERE for 31″ to 17″ 6mm Creedmoor Barrel Test Report »
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January 21st, 2019
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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September 9th, 2018
Barrel nut system allows “Pre-Fit” barrel installation on a Remington action. CLICK photo to zoom.
REMAGE Project Report by Bill, Rifleshooter.com Editor
Installing a new barrel on your Remington 700 (especially without a lathe) may seem like a daunting task, but thanks to companies like McGowen Precision Barrels, there are easier alternatives. By adopting a Savage-style barrel nut on a 1 1/16″ thread for a Remington 700 receiver, pre-chambered (aka “pre-fit”) barrels can be easily swapped with just a few hand tools. This system is sometimes called a REMAGE conversion (for “REMington savAGE”). With simple tools a “Pre-fit” 6mmBR-chambered barrel was installed on the author’s Remington action — no machining or lathe-work required.
Using a few tools from Brownells: Remington 700 Action Wrench, Barrel Vise, Go and No-Go Gauges, Recoil Lug Alignment Tool, and a Savage Barrel Nut Wrench, I was able to swap the .308 Winchester barrel off of my Remington 700 short action and install the new McGowen pre-fit, pre-chambered barrel, converting it to a tack-driving 6BR (aka 6mmBR Norma).
The existing barrel is simply removed from the action (normally the hardest part) and the new barrel is screwed on with the Go Gauge in place. After headspace is verified with the Go Gauge, the barrel nut is tightened against the action and you are off to the range. It takes all of the machine work out of the barreling process.
Note: Because barrel nut has a slightly larger diameter, some stocks may require minor inletting. Also, if you are shooting fired brass from another rifle with the same chambering, you should FL-size the brass before loading it for your new pre-fit barrel. And always check the set-up with a dummy round loaded to normal cartridge length BEFORE you head to the range. With Pre-Fits, the freebore should be adequate for your cartridge, but always check and adjust your seating depth as needed.
My McGowen Remage barrel looks and shoots great. I’ve written two longer articles that provide greater detail about this project. To learn more about how the barrel was installed, read: Rebarrel a Remington 700 without a lathe: McGowen’s Remage barrel conversion. To see how the rifle performed at the range, read: McGowen Remage Barrel Review: Spoiler Alert- It Shoots!.
Bill has been a serious shooter for over 20 years. A former Marine Corps Sergeant, he’s competed and placed in High Power Rifle, ISPC, USPSA, IDPA, 3-Gun, F-Class, and precision rifle disciplines. In addition to being an NRA-certified firearms instructor and range officer, Bill has hunted big game in North America, South America, and Africa. Bill writes extensively about gunsmithing, precision rifles, and the shooting sports on his blog, Rifleshooter.com.
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August 12th, 2018
Rifleshooter.com does some great original research — providing “hard data” you can’t find anywhere else. Here are the eye-opening results of Rifleshooter.com’s 6.5 Creedmoor barrel cut-down test. You may be surprised at the results. Read on…
What do you get when you cut a 6.5 Creedmoor-chambered barrel down to just over 16 inches? A lot more velocity than you might think. Our friends at Rifleshooter.com recently did a barrel cut-down test with 6.5 Creedmoor test rifle, shortening the barrel from 27 to 16.1 inches in one-inch increments. Surprisingly, with a 142gr Sierra MK, the total velocity loss (as measured with a Magnetospeed) was just 158 FPS, an average of 14.4 FPS per inch of barrel length. With the lighter 120gr A-Max bullet, the total velocity loss was 233 FPS, or 21.8 FPS average loss per inch of barrel.
To perform this velocity test, our friend Bill, Rifleshooter.com’s editor, built up a 6.5 Creedmoor rifle using a Remington Model 7 action, 1:8″ twist Green Mountain CM barrel, and MDT LSS Chassis, all obtained from Brownells.com.
Test Procedure
Five (5) rounds of each type of cartridge were fired at each barrel length and the velocity data was recorded with a MagnetoSpeed V3 barrel-mounted chronograph. The rifle was then cleared and the barrel was cut back one inch at a time from 27″ to just over 16″. NOTE: During this winter test, the air temperature was a very chilly 23° F. One would expect higher velocities across the board had the outside temperature been higher.
The photo below shows how the barrel was cut down, inch-by-inch, using a rotary saw. The barrel was pre-scored at inch intervals. As the main purpose of the test was to measure velocity (not accuracy) the testers did not attempt to create perfect crowns.
6.5 Creedmoor vs. Other Mid-Sized 6.5mm Cartridges
The 6.5 Creedmoor is a very popular cartridge with the tactical and PRS crowd. This mid-size cartridge offers good ballistics, with less recoil than a .308 Winchester. There’s an excellent selection of 6.5mm bullets, and many good powder choices for this cartridge. When compared to the very accurate 6.5×47 Lapua cartridge, the 6.5 Creedmoor offers similar performance with less expensive brass. For a tactical shooter who must sometimes leave brass on the ground, brass cost is a factor to consider. Here’s a selection of various 6.5mm mid-sized cartridges. Left to right are: 6.5 Grendel, 6.5×47 Lapua, 6.5 Creedmoor with 120gr A-Max, 6.5 Creedmoor with 142gr Sierra MK, and .260 Remington.
When asked to compare the 6.5 Creedmoor to the 6.5×47 Lapua, Rifleshooter.com’s editor stated: “If you don’t hand load, or are new to precision rifle shooting, get a 6.5 Creedmoor. If you shoot a lot, reload, have more disposable income, and like more esoteric cartridges, get a 6.5×47 Lapua. I am a big fan of the 6.5×47 Lapua. In my personal experience, the 6.5×47 Lapua seems to be slightly more accurate than the 6.5 Creedmoor. I attribute this to the quality of Lapua brass.” Now that Lapua offers 6.5 Creedmoor brass with small primer pockets, the 6.5 Creedmoor is even more attractive.
The creator of Rifleshooter.com also operates a Custom Rifle Building enterprise and gun shop in Long Island, New York: 782 Custom Guns Ltd.. He tells us: “We offer an unparalleled level of gunsmith machine shop services in the Long Island region. From precision rifles (USMC M40A3/A5/A6 XM3 clones) to customized Remington 870 and Mossberg 590 shotguns, and customized 1911s, chances are if you can dream it, we can build it!”
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