February 16th, 2017

6.5 Creedmoor vs. Other Mid-Sized .264-Caliber Cartridges

6.5 Creedmoor Rifleshooter.com velocity barrel cut cut-down test saw blade

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 options. 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.” But now that Lapua is producing top-quality 6.5 Creedmoor brass with small primer pockets, we could have a “second generation” 6.5 Creedmoor that rivals ANY mid-sized cartridge for efficiency AND accuracy. We will soon know how well the 6.5 Creedmoor cartridge performs with Lapua brass.

The first shipment of Lapua 6.5 Creedmoor brass has arrived in the USA. It features a small flash hole and small primer pocket. We have some for testing…

Lapua 6.5 Creedmoor Brass

New Lapua 6.5 Creedmoor Brass Field Tests Soon
Our friends at 65Guys.com will be testing the new Lapua 6.5 Creedmoor brass next week. The goal will be to determine if Lapua’s new Small Primer Pocket/Small Flash Hole brass allows higher velocities than American-made brass (Hornady specifically). In addition the 6.5 Guys want to see how well the new Lapua brass holds up after dozen (or more) firing cycles. They’ll hammer the new brass pretty hard to see how it fares with repeated stout loads. Stay tuned…

Sierra 6.5 Creedmoor Load Data Manual reloading .264

Here are three tables from the Sierra Bullets Reloading Manual (5th Edition). IMPORTANT — This is just a sample!! Sierra has load data for many other 6.5mm bullet types, including FB, Spitzer, SBT, HPBT, and Tipped MK from 85 grains to 142 grains. To view ALL 6.5 Creedmoor DATA, CLICK HERE.

Sierra Bullets 6.5 Creedmoor Load Data MatchKing Tactical
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.

Sierra Bullets 6.5 Creedmoor Load Data MatchKing Tactical
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.

Sierra Bullets 6.5 Creedmoor Load Data MatchKing Tactical
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.

Permalink Bullets, Brass, Ammo, Gear Review 19 Comments »
January 1st, 2017

6.5 Creedmoor — Velocity and Barrel Length — What to Expect

Rifleshooter.com 6.5 Creedmoor cut-down test

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.

CLICK HERE to SEE All Velocity Values at All Barrel Lengths

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.

Read Full Story with All Test Results at Rifleshooter.com

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.

Rifleshooter.com 6.5 Creedmoor cut-down test

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 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 6.5 mm 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.

6.5 Creedmoor Rifleshooter.com velocity barrel cut cut-down test saw blade

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.”

Permalink Bullets, Brass, Ammo, Gunsmithing, Tactical 2 Comments »
November 15th, 2016

First Test: Sierra .30-Cal 195gr Tipped Match King (TMK)

Sierra 195 grain Tipped Match King Rifleshooter.com

Our friend Bill at Rifleshooter.com got his hands on some of Sierra’s brand new .30-Cal match bullets, the 195-grain Tipped Match Kings (TMKs). These feature an impressive 0.610 G1 BC above 2000 fps. We predict these new bullets will be popular with F-TR shooters shooting the .308 Winchester cartridge.

To see how the new 195gr TMKs perform, Bill loaded up some .308 Win ammo with IMR 4064, ranging from 40.5 grains up to 42.5 grains. That gave him a velocity range of 2438 FPS at the lowest charge weight, up to 2552 FPS at 42.5 grains. This was with a relatively short, 22-inch barrel. Best five-shot accuracy (and second lowest SD) was at 41.0 grains even, producing a 0.498 MOA five-shot group at 2480 fps (6.1 SD). CLICK HERE for full accuracy results.

>> READ Sierra 195gr TMK Test Report on Rifleshooter.com.

I headed to the range on a brisk November day. Targets were 2″ orange dots at 100 yards. All shooting was done prone from a bipod with a rear bag. The Nightforce 3.5-15X scope was set at 15X. All ballistic information was recorded with a MagnetoSpeed barrel-mounted chronograph. Temperature was 54° F. Standard deviation for the loads ranged from 5.3 to 20.5 FPS. Average standard deviation was 12.5 FPS. Five-shot group sizes ranged from .521″ (.498 MOA, ) to 1.057″ (1.010 MOA). Average group size for all ten loads was .692″ (.661 MOA).

Sierra 195 grain Tipped Match King Rifleshooter.com

New 195gr TMK offers Impressive Long-Range Ballistics

Sierra 195 grain Tipped Match King Rifleshooter.com

Bill was also interested in how the ballistics of the new 195gr TMKs compared to other .30-cal projectiles. Even with a moderate, 2539 fps velocity, the new 195gr TMK showed less wind drift than other Sierras, thanks to its high 0.610 G1 BC. It also had a flatter trajectory beyond 600 yards than the 175gr and 190gr Sierra MatchKings. (The faster-flying 175gr TMK had slightly less drop at all yardages.)

Bill explains: “For comparison purposes, I selected the 42.0 grain load, with a muzzle velocity of 2,539 feet/second and an SD of 6.9. This load is compared to loads for the 190 SMK, 175 SMK, 175 TMK, and 168 Federal Gold Medal ammunition in the test rifle. In other words, these aren’t maximum loads, but loads that I have developed and would feel comfortable shooting a match with in the rifle shown (you may note the 190 SMK is fairly slow, but this is what the rifle liked). Also note that this rifle has a relatively short 22″ barrel compared to those you might find on a purpose built f-class rifle.”

Bill provides a full write-up on the Rifleshooter.com website complete with target photos and load details. If you are interested in these new 195-grainers, you should read the full report.

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August 6th, 2016

How Velocity Changes with Barrel Length — .223 Rem Test Results

.223 Rem Cut-Down Test barrel UMC m855

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.

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. (See inch-by-inch data HERE.)

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.

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.

Permalink Gunsmithing, Reloading No Comments »
May 29th, 2016

Barrel Length and Velocity in a .223 Rem — Barrel Cut-Down Test

.223 Rem Cut-Down Test barrel UMC m855

We often receive questions from varmint hunters and AR shooters regarding barrel length. They want to know how much velocity they will loose if they run a shorter barrel in their .223-Rem rifle. Our friends at Rifleshooter.com did a test that provides some surprising answers to that question.

With barrels, one always wonders “Can a little more length provide a meaningful velocity gain?” To help answer that question, 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.

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. (See inch-by-inch data HERE.)

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.

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.

Permalink Gunsmithing, Tech Tip 4 Comments »
April 24th, 2016

.308 Win Barrel Chop Test: How Velocity Changes with Length

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

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.

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

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:

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

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.”

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

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.

Permalink - Articles, Gunsmithing, Tactical 2 Comments »
March 28th, 2016

6.5 Creedmoor — Barrel Cut-Down Velocity Tests

Rifleshooter.com 6.5 Creedmoor cut-down test

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.

CLICK HERE to SEE All Velocity Values at All Barrel Lengths

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.

Read Full Story with All Test Results at Rifleshooter.com

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.

Rifleshooter.com 6.5 Creedmoor cut-down test

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 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 6.5 mm 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.

6.5 Creedmoor Rifleshooter.com velocity barrel cut cut-down test saw blade

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.”

Permalink Gunsmithing, Tactical, Tech Tip 2 Comments »
July 11th, 2015

Tactical Transformer: .243 Win Becomes a 6-6.5×47 Lapua

6mm-6.5x47 6x47 Lapua Tactical Accuracy International

Article by Bill, Editor of Rifleshooter.com
A few years ago I built a custom switch-barrel Remington 700 on an AICS Chassis chambered in .243 Winchester and .308 Winchester. I found the .243 Win finicky during load development and started looking at other options for the 6mm Bartlein 1:8″-twist HV barrel.

6mm-6.5x47 6x47 Lapua Tactical Accuracy InternationalInitially drawn to the 6mmBR and 6mm Dasher, I realized these cartridges wouldn’t feed from an AICS magazine system without extensive modification. I took a look at the 6mm Creedmoor, 6XC, and 6mm-6.5×47 Lapua (aka 6×47 Lapua), all of which feed well from a detachable magazine. At right you can see the 6×47 Lapua in an AICS magazine. It has the “Goldilocks factor” — not too long, not too short.

The ability to simply convert 6.5×47 Lapua brass to 6×47 brass by running the parent 6.5mm brass through a full-length Forster sizing die in a single step was what made me choose the 6×47 Lapua over the 6mm Creedmoor and 6XC (both excellent cartridges in their own right). I also own a 6.5×47 Lapua rifle, so I had a supply of 6.5×47 brass ready to neck-down. Being able to create 6×47 brass easily (one pass and done) was very appealing.

Left to right, below: 6mmBR, 6-6.5×47 Lapua, 6.5×47 Lapua, and .243 Winchester.
Rifleshooter.com6mm-6.5x47 6x47 Lapua Tactical Accuracy International

I cut the chamber end off my .243 Win barrel, threaded and chambered my rifle for the 6×47 Lapua cartridge. I have written a lengthy article on this cutting and re-chambering process. Home gunsmiths interested in this process can READ MORE HERE.

When the re-chambering was complete, I headed to the range and worked up a set of eight loads using Berger 108 BTHPs, H4350, Lapua brass, and CCI 450 primers.

Rifleshooter.com 6mm-6.5x47 6x47 Lapua Tactical Accuracy International

Load development was a little trickier than with the 6.5×47 Lapua parent cartridge. The accuracy nodes were smaller. However, once I dialed in a load with Hodgdon H4350 and the 108-grain Berger BTHP, the rest was history. The 6×47 rig is now one of the most consistent rifles I own, holding just above 0.3 MOA for 5-round groups. Below is a 100-yard test target with 108-grain Berger BT in the 6×47 Lapua. Five-shot group sizes are (L to R): .369″, .289″, and .405″. The average size was .354″ or .338 MOA. [Editor: We think that is excellent accuracy for a tactical-type rifle shot from bipod.]

6mm-6.5x47 6x47 Lapua Tactical Accuracy International

Learn More about this 6×47 Lapua Project
I’ve written more about this 6×47 rifle on my Rifleshooter.com website. To learn more about my experience with the 6×47 Lapua, click this link: 6-6.5X47 Lapua Review.


About the author: 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.

Permalink - Articles, Gunsmithing, Tactical 1 Comment »
July 9th, 2015

6mmBR “REMAGE” Conversion by Rifleshooter.com

Remage Savage Remington Rebarrel Rifleshooter.com 6BR 6mmbr
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”).

Remage Savage Remington Rebarrel Rifleshooter.com 6BR 6mmbr

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. The barrel nut is tightened against the action, headspace verified with the Go Gauge, and you are off to the range. It takes all of the machine work out of the barreling process. Note: the barrel nut has a slightly larger diameter and 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.

remage 6mm BR 108 berger best group 360

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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July 5th, 2015

RifleShooter.com Reviews New .30-Cal 175gr Tipped MatchKings

AccurateShooter Rifleshooter.com Tipped Matchkings Sierra Bullets

We know our readers are curious about the new Tipped MatchKings (TMKs) introduced by Sierra Bullets this year. Our friend Bill at Rifleshooter.com got hold of some of the .30-Cal 175-grain TMKs and tested them in his .308 Win rifle. He found the bullets were very consistent in weight. As for bearing surface, the SD was fairly low (.002″), but measurements varied from 0.400″ to 0.407″. Seven-thousandths extreme spread is more than we like to see, as it may affect accuracy. Therefore we recommend you sort by bearing surface length before loading these in match rounds.

READ Full Sierra 175gr TMK Bullet REVIEW in Rifleshooter.com »

AccurateShooter Rifleshooter.com Tipped Matchkings Sierra Bullets

(more…)

Permalink Bullets, Brass, Ammo, Gear Review 5 Comments »
June 4th, 2015

.308 Win Barrel Cut-Down Test: Velocity vs. Barrel Length

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

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.

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

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:

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

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.”

rifleshooter.com barrel .308 win cut-down test saw ammo GMM velocity magnetospeed

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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