Cutting edge firearms manufacturers are always trying to push the limits: using new exotic materials, developing new cartridges or finding new niches to push an existing offering into are just a few of the ways this boundary testing manifests itself. While .300 Blackout is still a relatively new caliber, that hasn’t stopped manufacturers from chopping the barrels shorter and shorter to the utmost edges of usability. So far, I haven’t found a comprehensive collection of data on these barrels as some are very new. So I’ve set out to do my own data gathering for the benefit of an informed marketplace. These articles aren’t to tell you which is “best”, as each has a different price point and different features, rather to help you decide which is best for your purposes. For the purpose of this article, “ultra-short” is defined (by me) as being under 7″.
(AUTHORS NOTE: After receiving emails in the days and weeks after this went live, ammo manufacturers and a barrel manufacturer agreed that the barrels need a break-in period before optimal accuracy results can be tested. All accuracy results should be considered preliminary. Once ALL barrels have been received and given initial testing, a follow-up article will cover final accuracy testing.)
The first two items I received were the V Seven Weapon Systems 6.5″ barrel and the Right To Bear 6″ barrel. Hereafter they will be referred to as the V7 and R2B. Let’s talk tech specs before looking at chronographed velocity data and group sizes.
V7 6.5″ with gas block and gas tube. Data from V7’s site:
- Stainless steel 416R, Rockwell 30-32
- 1:7 twist rate
- 5/8 X 24 Threads
- Barrel extension features true .30 cal improved, extended feed ramps & Melonite black finish
- Weighs 15 oz w/ included 17-4 stainless pin-on gas block & proprietary Inconel straight gas tube in Ionbond.
- Gas system: proprietary length and height (.5″ shorter than pistol, slightly taller)
- Gas port size: .105 (but again, note that the system length is shorter)
- Gas block journal: .750″
- Price: $299 (fluting available at additional cost).
Right To Bear, 6″ barrel. Data from R2B’s site:
- 4150 Chrome Moly Vanadium with QPQ corrosion resistant finish
- 1:7 Twist rate, 5R
- 5/8 x 24 Threads
- Weight – 14oz
- Gas System Length – Pistol
- Gas Port Size- .105″
- Gas Block Journal – .750″
- Price: $119.99
These two barrels were both assembled onto uppers by me. The R2B barrel was encircled by a discontinued YHM handguard and an MP5SD handguard. The V7 barrel came with a 5.7″ handguard, also from V7, with a Sig Mp5K-style foregrip.
Both uppers were used on the same SBR lower, with Geiselle Single Stage Precision (SSP) trigger, standard weight buffer and MFT Minimalist stock. I used a Leupold 1-4x HogPlex scope on both uppers as well. Given that one barrel was shorter than the handguard I had available, both were shot with SAS’s blast diverter and will likewise share my SAS Reaper Ti suppressor when applicable. All firing was done from a Caldwell Stinger shooting rest at 50 yards for groups and through a Caldwell Ballistic Precision chronograph at the recommended 10-foot distance.
Four ammo types were chronographed, while groups were only done with three types due to limited quantity on hand with one type. Those four makes of ammo used were the Barnes RangeAR 90gr round (chrono only), Barnes Tac-TX 110gr, Federal all-Copper 120gr and the Fiocchi 220gr subsonic round provided by Fiocchi specifically for this article. Various mags used, no jams or feed issues, all supers locked back the bolt on the last round.
Lacking sweet chart making skills, here’s the chronograph AND group size results by ammo type:
Barnes RangeAR 90gr
- V7: Average 2166 FPS, Standard Deviation (SD) 37- no groups shot
- R2B: Average 2104 FPS, SD 19- no groups shot
Barnes Tac-TX 110gr
- V7: Average 1977 FPS, SD 14- 1.7″ & 1.86″ (3.24 MOA & 3.55 MOA)
- R2B: Average 1923 FPS, SD8 – 1.83″ & 2.3″ (3.49 MOA & 4.3 MOA)
Federal Copper 120gr
- V7: Average 1794 FPS, SD 8- 1.25″ & .85/1.83″ (one called flyer) (2.3 MOA & 1.6/3.49 MOA)
- R2B: Average 1735 FPS, SD 8- 1.35″ & 1.83″ (2.57 MOA & 3.49 MOA)
Fiocchi 220gr Subsonic
- V7: Average 810 FPS, SD 14- 2.2″ & 2.4″ (4.2 MOA & 4.58 MOA)
- R2B: Average 835 FPS, SD 9- 1.55″ & 2.27″/3.58″ (one called flyer) (2.96 MOA & 4.33/6.8 MOA with flyer)
- Note: V7 cycled subsonic rounds unsuppressed, didn’t lock back. R2B was manual cycle while unsuppressed.
Average group sizes (one flyer each barrel not included here)
- V7 Supersonic-2.67 MOA, Subsonic 4.39 MOA
- R2B Supersonic- 3.46 MOA, Subsonic 3.64 MOA
So let’s make a few observations with the data. First, you may notice each barrel had one flyer, though with different ammo. I included the data, you can make your own decision as to whether you want to include those shots in your decision making.
Second thing I noticed was that the R2B barrel had demonstrably better standard deviations. Both barrels were brand new, not broken in… both were shot with the same lot numbers of ammo from the same boxes. Perhaps the V7 barrel had a burr? I’m not certain, but it didn’t translate to the third observation:
Third item I noticed was included in the average group size section: The V7 barrel was more consistently accurate across supersonic ammo types, while the Right To Bear barrel was more consistent with the only type of subsonic round I was able to get a hold of.
Both barrels averaged out a little worse than I thought. Only one group made it into the 1-2 MOA range, which was the V7 barrel using the Federal all-copper round. Not coincidentally, this was the most accurate round from the R2B barrel as well. I think I could have shot a bit better had I used an optic that had a finer reticle, the HogPlex is an excellent hunting reticle but obscured more of the orange dots than I liked. Too late to go back now though, I don’t have enough rounds to continue with the next 2-3 barrels coming in an “apples-to-apples” fashion while re-doing this stage.
So there’s your data so far. I have manufacturer confirmation that the Veritas 5″ .300 blackout micro Ar barrel assembly is coming with a handguard from SLR Rifleworks and a Modern Outfitters MC6-SD 6″ pistol coming. I’m also working to see if I can acquire the KAK 6.25″, 4.75″ and Special Ops Tactical 5.9″ or 6.75″ barrel to include.
(Update one month later: During the next test date, more ammo types were available. Some additional chrono data for these two barrels are available in Part 2)