Like many others in the precision rifle crowd, we were extremely excited to see Bartlein Barrels release their new Carbon Fiber Wrap (CFW) barrel blanks to market. Bartlein is an established heavyweight in the premium barrel market, holding numerous world records for accuracy across a wide range of shooting disciplines. They support competitive shooters in an incredible way; I cannot remember the last major PRS or NRL match I attended that did not have a Bartlein Barrel certificate on the prize table. They are currently the most requested blank manufacturer by our customers, and for good reason. They are well known to just flat out shoot. Our purpose in testing was to determine if the new carbon wrapped option would live up to the reputation established by the company’s excellent steel barrels.
The first thing we noticed on our test barrel blank was the amount of steel left on both the breech and muzzle end, compared to some of the other carbon barrel makers. Bartlein approaches barrel making from the perspective that accuracy and consistency are of utmost importance; weight savings are secondary. To that end, the breech end of their barrels features more steel to support the thread tenon in the action, and the chamber and throat during extended firing. The muzzle end also has a longer steel section, giving more support to muzzle threads for suppressor use. We are also told by Bartlein that the steel liner geometry under the carbon wrap is optimized for maximum support on both ends, with the knowledge that suppressor use is common and must be accounted for in the design of the barrel blank. This makes their carbon barrel blanks slightly heavier than that of competitors’ products, but the design features bear serious consideration if you plan to run your rifle hard.
Straightness and uniformity of the barrel was perfect. Bartlein marks all of their finished barrels with the final bore and groove dimensions on the breech end, and they exactly matched our results when gauging. The bore finish of our blank was impeccable, with no defects found on either lands or grooves. Once in the lathe and indicated true to bore, outside diameter concentricity to bore was within .002″. This has been a hallmark of Bartlein blanks for as long as we’ve used them, and it was great to see the same workmanship in the new design as well.
Bartlein is offering their carbon fiber blanks in four finish lengths (20″, 22″, 24″, and 26″), and three contours. Available contours are their #4 Bull Sporter, #13 Remington Varmint/Sendero, and the #14 M24/M40. The outside dimensions of all three contours are the same for the carbon barrels as for the steel which is helpful in figuring the exact amount of weight savings for each type, and especially helpful to builders and stock makers who already have established inletting programs for those contours. The company is maintaining a good selection of CFW blanks built and ready to ship, and you can find a list of available blanks here:
We chambered our test barrel with a Manson 7mm SAW II reamer, as this caliber was a perfect choice to test the barrel’s performance and compare data to test data from the many other builds chambered for the same cartridge. Our test barrel has a finished length of 24″, and a twist rate of 1 turn in 8.5 inches. We chose the #13 Remington Varmint/Sendero contour, and feel that this will be an extremely popular size with our customers.
Barrel Break in and Test Data
Barrel break in was completed with a Dead Air Armament Nomad-30 suppressor attached.
Break in load:
171 Barnes Match Burner HPBT
WTO 5x Brass, annealed
2682/15.4 over first 10 shots through barrel. Break in roughly 1 MOA, with exception of one called flyer.
Barrel was cleaned after shot number 10, shots 11-15 fired were loaded as follows:
166 Hornady A-Tip, 2.225”BTO/2.950” OAL, 44.5gr H4350, CCI450, 5x Brass, produced 2708FPS/8.5SD, .225” bughole group
162ELD-M, 2.945”OAL/2.255”BTO, 44.5 H4350, CCI450, 5x Brass
Shot in approaching thunderstorm, wind high and switching from all directions
Group 1: .769”
Group 2: .869” 5 shot
Cold Bore Shift Test, shots 24-29
Same load data as above, 1 shot fired from completely cold barrel and suppressor, followed immediately with 2nd shot. Repeated 3 times. Worst 2nd round deviation was .426” from cold bore shot. The others were not measurable, as the shots were touching and subsequent shots had made exact measurements impossible.
Muzzle device testing
Same load data as above. Wind 13-15 and gusty.
2711/2.2, .8” group.
2718/10.8, .5” group. Less than .5MOA POI shift, at 8:00 position from bare muzzle.
2704/4.5, .7” group. POI is 1.7” high from bare muzzle.
Heat stress test
Rifle configured with Tank-ST brake for heat test. Same test load as used for muzzle device testing. Three consecutive 3 shot groups were fired, allowing the barrel to cool 2 minutes in between shots to determine accuracy baseline. Wind during groups was 13-18MPH gusty full value.
Group 1: .790”
Group 2: .383”
Group 3: .862”
Average group size: .678”
2704/5.2 across all shots fired
Rapid fire test, 10 rounds fired as fast as target could be reacquired. Ambient temp was 81 degrees.
First three shots went in .370”. Total group size was .966”
2712/9.0SD over all shots fired
The Bartlein CFW blanks are exactly as promised, producing accuracy that is every bit equivalent to their well know steel barrels but with less weight. Of note is the observed POI shift from bare muzzle to suppressor, which was negligible. The barrel reacted as expected to the heat stress testing, remaining true to the original point of impact throughout the shot string. Accuracy did degrade with speed shooting, but remained sub-MOA and produced the most accurate heat stress group of the three carbon fiber blanks tested. Cold Bore shift was statistically non-existent in this barrel, which is of extreme importance especially for a long range hunting rifle.
If you are considering what barrel blank to use for your next build, the Bartlein CFW’s deserve serious consideration. When used as part of a properly built rifle they can be counted on to shoot lights out, every time.