reloading 300 blackout for subsonic and supersonic

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

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nikuraba29
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Re: reloading 300 blackout for subsonic and supersonic

Post by nikuraba29 »

natchez has 1680 in stock. I just ordered two pounds and some primers and the prices after the HaMat fee are still better then most local places if they even have it.

S/F

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imyomama
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Re: reloading 300 blackout for subsonic and supersonic

Post by imyomama »

tctlrld wrote:
imyomama wrote:
tctlrld wrote:I don't see why a faster powder wouldn't cycle a carbine action. Most faster burning powder would result in a slightly higher pressure. I suppose it could have to do with duration and dwell time. All supersonic 5.56 (and 300 BLK loads?) are high 90s burn rate in a 16".

Quickload shows that 8gr of Li'l Gun pushing a 240gr SMK through a 9" would result in 1010fps, ~78% powder fill and ~97% burnt powder, at ~27000 PSI chamber pressure. Seems like something like that would make more sense. But I don't have the upper or components to try right now.

On a somewhat different note. Does anyone have the measurements for the 220gr SMK? OAL, small diameter of taper and length of taper measurements.
hum.. I loaded 8.5 gr of lil gun 2 weeks ago and they all went supersonic on my 9" with smk 220's .. and didn't cycle the action..

so that blows that theory!
my 220's are seated at 2.160 oal ... FYI..
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imyomama
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Re: reloading 300 blackout for subsonic and supersonic

Post by imyomama »

tctlrld wrote:I don't see why a faster powder wouldn't cycle a carbine action. Most faster burning powder would result in a slightly higher pressure. I suppose it could have to do with duration and dwell time. All supersonic 5.56 (and 300 BLK loads?) are high 90s burn rate in a 16".

Quickload shows that 8gr of Li'l Gun pushing a 240gr SMK through a 9" would result in 1010fps, ~78% powder fill and ~97% burnt powder, at ~27000 PSI chamber pressure. Seems like something like that would make more sense. But I don't have the upper or components to try right now.

On a somewhat different note. Does anyone have the measurements for the 220gr SMK? OAL, small diameter of taper and length of taper measurements.
i'm not sure if pressure is an indicator whether or not the gun will cycle versus the amount of gas generated...

obviously my 4198's are low pressure but cycled my action vs the lilgun which didn't ...
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"Are you gonna pull those pistols or whistle Dixie?" --- Clint Eastwood --- The Outlaw Josey Wales
imyomama
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Re: reloading 300 blackout for subsonic and supersonic

Post by imyomama »

well.. the verdict is in... the rifle works!
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Re: reloading 300 blackout for subsonic and supersonic

Post by 300Blk »

You shot Wilbur?
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LYNRDSKYNRD
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Re: reloading 300 blackout for subsonic and supersonic

Post by LYNRDSKYNRD »

"That'll do pig.....that'll do" :mrgreen:
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Hoop
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Re: reloading 300 blackout for subsonic and supersonic

Post by Hoop »

Winchester is a great powder for the 300-221.

I will dig my data out and report back. Seems it was 242 or 246 that was great for the research I did years back.
H110 was a close second.
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Re: reloading 300 blackout for subsonic and supersonic

Post by Old Wanderer »

I just purchased a 10" Noveski upper (300Blackout), and am waiting on my stamps for my 762 SD.

I played with some numbers in the computer, and wondered if anybody has tried some Blue Dot?? The program says in a 10" barrel and some 200 Gr. Matchking bullets if I load 6.5 Gr and should see 1040 fps and 100% burn. Should be easy on the can.

Anybody tried Blue Dot?
imyomama
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Re: reloading 300 blackout for subsonic and supersonic

Post by imyomama »

the question is would it generate enough pressure and gas to cycle the action ... few people have tried similar powders and got good velocities , but cycling an ar is a different animal all together .. please try some and let us know !!!
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Re: reloading 300 blackout for subsonic and supersonic

Post by 300Blk »

Subsonic powders that seem ok for 210+ grain bullets are:

A1680
Re-7 - may not fit depending on your OAL and bullet.
H-4198 (if your measure can handle it. My Harrells does not drop it well).

I don't think lighter bullets are a great idea for the AR.
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