300 Blackout Subsonic accuracy a joke???

Discussion about rifles in 300 AAC BLACKOUT (7.62x35mm), hosted by the creator of the cartridge.

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Kill By Number
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300 Blackout Subsonic accuracy a joke???

Post by Kill By Number » Thu May 14, 2015 5:21 pm

You see everywhere people claiming 1" groups all day at 100 yards but I have not found a load that will come close. Searching online I've found no 10 shot group pics at 100 yards. Even with whole forums dedicated to 300 blk I found no solid data. I have no trouble getting it to group at 50 yards but it spreads way out past that. I've seen some good supersonic groups but I'd like to see AR based 300 blk subsonic testing. PLEASE POST HERE ONLY PICTURES OF 10 shot groups or five 5 shot groups with NO adjustments for fliers. I don't care what you heard, just show me on paper AT 100 YARDS please. Tell us what rifle and ammo and any other pertinant info.

Also, the title of this thread is just to get you to read it. I do believe there are accurate 300 blk subsonic setups out there, I would just like to see some on paper and know how they are setup and what ammo.

My setup is a LMT 10.5" 300 blackout in a MRP platform with AAC SDN-6 silencer. Ammo tried Hornady 300 whisper, Gemtech 300 blk, Handloads with 208 Amax bullet and various powders EXCEPT Accurate 1680 which I do not have but have heard good things about.
Thanks in advance.

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Two-Dogs
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Re: 300 Blackout Subsonic accuracy a joke???

Post by Two-Dogs » Thu May 14, 2015 5:54 pm

Twist rate?

TMD
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Re: 300 Blackout Subsonic accuracy a joke???

Post by TMD » Thu May 14, 2015 7:15 pm

Come to think of it, I don't think I've ever shot my subsonic loads past 50 yards. I may have to mount one of my other scopes on my sbr and see what it will do at 100. My old eyes and a 4x scope won't get along too well at those distances

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300Blk
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Re: 300 Blackout Subsonic accuracy a joke???

Post by 300Blk » Thu May 14, 2015 7:24 pm

There is no centerfire rifle ammo that has better MOA at 50 yards than 100.

takiniteasy88
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Re: 300 Blackout Subsonic accuracy a joke???

Post by takiniteasy88 » Thu May 14, 2015 8:38 pm

Do I get a prize if I shoot sub moa groups this weekend.

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Re: 300 Blackout Subsonic accuracy a joke???

Post by jwb47 » Thu May 14, 2015 8:56 pm

I havent been really impressed with the 208 grain amax out of 3 different blackouts I have found 225 grain hornady match much more accurate and consistant . with my two ar 300 blackouts I cannot shoot moa because they are not set up for target shooting . my remington 700 in 300 blackout will come close to moa at 100 yds with the 225 grain hornady and 220 grain out law state bullets but no I cant do it all day long and I seriously doubt 95%of the recreational shooters out there can do it consistantly either . remember even a blind hog can find an acorn sometimes .

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ThreeHundredTraveler
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Re: 300 Blackout Subsonic accuracy a joke???

Post by ThreeHundredTraveler » Thu May 14, 2015 10:02 pm

Just my two cents on it. I have now built 7 AR rifles, two 5.56, one 300Blk, two 22LR, one 308Win and one 45Raptor. I don't think any of them are going to be MOA rifles as built. Short barrels, light weight, very poor stocks for proper head placement, and crappy hand holds up front.

Those with longer barreled traditional rifles may do a lot better.

Fun as hell to shoot though. The best so far is the 300Blk shooting Ozark Ordnance 147 grain FMJ. More or less 2 MOA. I will be loading the donor casings soon and will see if I can do any better. The Model 88 in 308Win shot groups of 3/4 MOA at 100 yards. The loads that did that can no longer be constructed. Herters 170 grain round nose, with Herters 102 powder. I did not have to do a whole lot of trial and error as an old goat that taught me to reload helped with the recipe. Gave that gun to my son many years ago to use hunting deer.

I do not shoot subsonic, what I have found with the 308 and Raptor are that optimum velocity where it peaks with powder charge gives the best groups. Less powder slower bigger groups, more powder but not much more velocity bigger groups. I have run about a hundred rounds each through those and am still tweaking loads. Unfortunately the dearth of powder is not helping much with being able to find the "best" load.

So for the OP you may have to load hundreds of rounds in various ways until you find the sweet spot for your gun. With a 10.5 inch barrel you are going to have a devil of a time holding tight groups at 100 yards.

Kill By Number
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Re: 300 Blackout Subsonic accuracy a joke???

Post by Kill By Number » Thu May 14, 2015 10:40 pm

My twist rate is 1:7". Thanks for the info. I'd be happy with 2.5 moa if it was consistent. Anyone with group pictures? I will take some pics of my experiences next time.

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BadKarmaZeroSix
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Re: 300 Blackout Subsonic accuracy a joke???

Post by BadKarmaZeroSix » Fri May 15, 2015 12:49 am

Image
Not at home, so i can't tell you the exact load, but it was A1680 powder, rem7.5 primer, and 208 amax at 50 yds...5 shot group, from Rem 700SPS 16" non-suppressed off of bipod, zero wind, warmer day...i gotta get home for exact load...don't know exact measurement, but the brass should give you a good idea...
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DustyJacket
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Re: 300 Blackout Subsonic accuracy a joke???

Post by DustyJacket » Fri May 15, 2015 7:31 am

Here are some groups at 50 yards using a red-dot with a 4MOA dot, AR with Wilson Combat barrel, "on TRGET" 208GR SUBSONIC:

Image
Shoot softly, and carry a big clip.

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