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Finally fired mine yesterday. 6.5" V7 barrel shooting factory Hornady 110 gr Vmax. Only shot 5 rounds down the barrel, I don't have any sights on this sumbitch yet. Checked for function, everything was good. Chronographed 2 rounds. Velocity was 2034 and 2061. 2100 fps should not be that hard to attain with handloads hopefully. I'll check accuracy next. View Quote |
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If those are typical velocities for that short a barrel then I just changed my mind about 300BO. I assumed that shorty would be around 1800fps. View Quote View All Quotes View All Quotes Quoted:
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Finally fired mine yesterday. 6.5" V7 barrel shooting factory Hornady 110 gr Vmax. Only shot 5 rounds down the barrel, I don't have any sights on this sumbitch yet. Checked for function, everything was good. Chronographed 2 rounds. Velocity was 2034 and 2061. 2100 fps should not be that hard to attain with handloads hopefully. I'll check accuracy next. |
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No update of worth, had a big range day with camerman and all, cancelled due to heat. Left town for a few days, just got back, working on scheduling first range day before triggercon.
Also still waiting on Veritas/slr upper and Mc6-sd Fiocchi sent 250 subs though, so theres good news there |
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So I shot a Sig Rattler today and the compact size is damn nice. What advantages other than being piston driven does the Sig offer that a 5" AR platform doesn't? Other than obvious cost and cool factor and as we all know looking cool is the most important thing.
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So I shot a Sig Rattler today and the compact size is damn nice. What advantages other than being piston driven does the Sig offer that a 5" AR platform doesn't? Other than obvious cost and cool factor and as we all know looking cool is the most important thing. View Quote Ability to quickly/easily change handguard Ability to quickly/easily change stock 5.5” Rattler will be shorter than 5.5” AR, since there’s no buffer tube and a Law folder adds length. |
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Quoted: Ability to quickly/easily change to another barrel length/caliber (Rattler is just a “mini” MCX chassis) Ability to quickly/easily change handguard Ability to quickly/easily change stock 5.5” Rattler will be shorter than 5.5” AR, since there’s no buffer tube and a Law folder adds length. View Quote I did get an email from BA about their new 6". For the price I'm really considering it. |
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first range day complete. quick info dump, details will be in the article. very tired, no grammar editing tonight.
at 50 yards, 4x optic, standard weight carbine buffer, 3 ammo types, barnes 110 ttsx, federal copper 120 gr, fiocchi 220gr subs 1" at 50 is 1.9 MOA R2B shot 1.3" to 2.3" groups (the 2.3" had a called flyer, would have pushed it to 3.78". I shanked it totally). V7 shot .85" to 2.4" groups. the .85" had a called flyer, out to 1.83" if included. next best group was 1.25" r2b preferred the federal copper for 1.3" and 1.8" groups v7 likewise posted best groups with federal, .85" and 1.25" r2b didnt cycle subs without can v7 cycled subs but didnt lock last round subs were the worst groups for both guns, by a good margin. in the article I may tally totaly for supers and subs seperately. will try to get velocity data posted tomorrow. shot barnes rangeAR through chrono as well, not enough on hand for groups |
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velocity data 70 deg F:
barnes rangeAR 90gr v7 2154, 2164, 2195, 2111, 2207 r2b 2116, 2070, 2110, 2116 barnes ttsx 110gr v7 1975, 1961, 1972, 1978, 2001 r2b 1917, 1916, 1937, 1920, 1925 Federal copper 120gr v7 1779, 1799, 1798, 1792, 1802 r2b 1735, 1739, 1723, 1732, 1748 fiocchi 220gr v7 797, 798, 828, 806, 824 cycled unsuppressed, no lock back r2b 838, 828, 849, 822, 838, did not cycle unsuppressed |
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I think I am going to go down the ultra short 300 blkout rabbit hole. I have a 10.5" sbr in 300 blkout already. Thinking about doing a 5" upper or maybe another sbr build.
My question is with your early testing. Are you finding a sweet spot as far as buffers? I plan to shoot suppressed and probably all subsonic. Definitely an adjustable gas block. What buffer weight would be a good start on these ultra short barrels? |
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@vbpylot So far with the v7 6.5” and r2b 6”, as well as one other v7 6.5 I owned a while back, I have only used the standard buffer. I brought h2 and h3’s to the range but didn’t need them. Didn’t run more than a couple rounds suppressed, that will be later, wanted a good keyhole check first.
As for where to start: I just start with whatever I have on hand and go from there. Often enough, the first one I try works just fine |
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Standard makes sense. Alot of gas from a suppressor to begin with. Definitely watching your testing. Curious what your suppressed results are. Thanks for doing this and thanks for the response.
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KAC recommends changing some of the buffer weights to aluminum , with there 6.25" barrel to cycle subs without a suppressor. Mine is a little under gassed and short strokes with Nosler 110 Varmagedon so I am going to lighten the buffer some. It ran fine with Fiochii 150gr FMJ supers.
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KAC recommends changing some of the buffer weights to aluminum , with there 6.25" barrel to cycle subs without a suppressor. Mine is a little under gassed and short strokes with Nosler 110 Varmagedon so I am going to lighten the buffer some. It ran fine with Fiochii 150gr FMJ supers. View Quote |
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kac has a 6.25" barrel? View Quote https://www.kakindustry.com/ar-15-parts/upper-parts/barrels/300-blk/6-25-inch/kak-300-blackout-625-inch-pistol-stainless-barrel-5r7 |
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Article Part 1 is live
https://loadoutroom.com/50929/ultra-short-300-blackout-barrels-round-up-part-1/ |
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Pic request....
I’ve been eyeballing the Vseven 5.7” rail, but there doesn’t seem to be too many out in the wild. Can you post a few more pics of it on the gun? Bonus points for pics with suppressor mounted. |
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Pic request.... I’ve been eyeballing the Vseven 5.7” rail, but there doesn’t seem to be too many out in the wild. Can you post a few more pics of it on the gun? Bonus points for pics with suppressor mounted. View Quote |
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I'll go snap a couple more today If I get a few minutes in the shop
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KAK 6.25" and 4.75" both coming in. Need more ammo! work stash and personal stash both getting low
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they posted this on their instagram the other day, some guy testing one for them
https://www.youtube.com/watch?v=l35sPOQAYGg |
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Seriously interested in that 4.75" from KAK. I've got a deep stash of 110gr Barnes blacktips and are dying to see what velocities you will get from the ultra shortie
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What size gas port are they using in the 6 inch size barrels, specifically that KAK 6.5 inch barrel?
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Seriously interested in that 4.75" from KAK. I've got a deep stash of 110gr Barnes blacktips and are dying to see what velocities you will get from the ultra shortie 4.75 with barnes 110, around 1850 fps 6.25 with barnes 110, around 1950 fps |
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I get 2000 FPS with 19.0 of Lil Gun behind the 110 Tac-Tx out of a 8.5”... what loads are you shooting?
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Two barrels from KAK are in, doing some dremel ninja work with extra ALG handguards I had around. Ammo from Ammo inc is in, some Federal subs incoming and a couple boxes of Discreet Ballistics. https://i.imgur.com/vRXm5M7h.jpg https://i.imgur.com/S95esxSh.jpg https://i.imgur.com/Dmw01fth.jpg https://i.imgur.com/BVGinZ4h.jpg View Quote |
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.105 for the KAK 6.25 AND the 4.75", but the 4.75"'s gas post is closer in by 1.5" View Quote View All Quotes View All Quotes |
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Thanks again. I really appreciate it. I'm trying to decide whether to do another .30 HRT but in a 6.5 inch or do a .300 BO in 6.5 inch. No subs are in the plans and it will be a purely kicks and giggles build. Since I already have a couple of .30 HRTs, it would be interesting to try a short one and it would not cost me a new set of dies, but the BO is better suited to long and heavy bullets while the HRT is a lot better suited to short and fast bullets. Decisions, decisions, decisions...
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Article part 2 done, will be submitted for editing and publishing soon.
For those of you with more experience than me in the area of shooting groups, I have a question: If a barrel is shooting reasonably well (2-4 MOA, somewhat fast groups), then fires out a 14 MOA group.. whats the likely cause? Wasn't shooter error in this case. 4.75" KAK .300 blackout barrel, 1x7 twist, 120 gr Federal All Copper rounds, 50 yards, 4x ACOG |
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That’s quite a change. First word to come to mind is loose. Loose scope, loose mount, loose barrel nut, loose gas block, loose muzzle device, muzzle device strike... Check everything. Next would be clean. Has the barrel been cleaned down to base metal using copper remover?
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That’s quite a change. First word to come to mind is loose. Loose scope, loose mount, loose barrel nut, loose gas block, loose muzzle device, muzzle device strike... Check everything. Next would be clean. Has the barrel been cleaned down to base metal using copper remover? View Quote |
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Were these all with the same load? If they were all with the same load, getting good groups, then a bad group, then good groups again, I’d suspect the ammo in that case. Loose parts and heavily fouled barrels don’t just correct themselves mid shooting session. If that lone bad group was a separate load, then it could simply be a combo the barrel doesn’t like.
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Second article up.
Have a tracking number for Vertias Tactical/SLR upper with 5" barrel Modern Outfitters MC6-SD seems to have fallen off their "to-do" list None others pending https://loadoutroom.com/51926/ultra-short-300-blackout-barrels-round-up-part-2/ |
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