1:8 Lothar Walther blackout barrel

sniper79_98

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Nov 1, 2009
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Anyone running an 8 twist blackout barrel? Either a Spike’s or LW? I see Daniel Defense is turning them out as well. I’m wondering if anyone has shot 220 smk(s) through them. I’m concerned about gyroscopic/dynamic stability.(yes, the calculators show them as being stable) While every barrel is different, I’ve read that the idea behind the 8 twist is to give the bullet more of a chance to tumble as there’s little chance of them expanding. These are being shot through a suppressor and any first hand experience or knowledge is appreciated.

Thank y’all!
 

chrismartin

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Aug 29, 2013
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All of my 300BLK barrels are 1:8 twist (Two AR's (8" and 9" range) and one Remington 700 (16")) that I have had since the 300BLK stuff got popular (since AAC announced it, but I didn't run any Whisper barrels or anything)
They shoot 220's just fine, but I haven't shot any game with them. I can't recall ever shooting my 300BLK's without a silencer.
I haven't ever had any stability issues with 220SMK's. There are better bullets to use for hunting than the 220 SMK's, including specialty subsonic tuned expanding bullets.
Most 300BLK barrels as far as I know have moved to faster twist than the "original" 1:8 stuff. 1:7 is common now and Q uses 1:5 twist for the Honey Badger and Mini Fix.
 

sniper79_98

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Nov 1, 2009
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Absolutely. That goes along with everything I’ve read as far as what was originally used, the performance on game and the current faster twist/ shorter barrels. I read where it was originally developed with an 8 twist and moved to a 7. I was hoping for feedback like yours because I’m concerned once the temperature drops the loads I’ve got around 1,000 fps now may be slow enough to cause a strike in 32f temperatures. Out of curiosity, would you tell me your experience with cold temperatures and velocities as well as what range you had a comfortable zero? I’m thinking 50-75 yds?
 

chrismartin

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Aug 29, 2013
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I can't really help with the tempurature. I can't recall shooting my 300blk's in winter. Those are more fair weather guns for me. LOL.
For my AR's, I use a 50 yard zero. For the Rem 700, I used 100 yard (higher magnification scope).
The most accurate factory subsonic ammo I found was Silencer Co Harvester, but I don't think they make it any longer. It was very good out of my rifles.
Other than that I loaded my own, usually keeping around the original 220SMK and AA 1680 recipe (I can't find my notes right now).
 

Geno C.

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  • Oct 24, 2007
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    Mine is a 8 and stabilizes anything I’ve put through it and subsonic speed. Up to a 240.
     

    hangunnr

    Team Shutupnshoot
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    Are you concerned that the bullet will tumble immediately after leaving the barrel and prior to exiting the suppressor? That’s what I took from your second post anyway. Can’t see that ever being a concern.

    I’ve shot my 8 twist rifle with 200smk and 220smk subs down to zero degree to verify I had enough gas to operate the rifle suppressed. Accuracy never suffered at the lower temps and no signs of instability.
     

    sniper79_98

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    Nov 1, 2009
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    You are correct. I was concerned that when the bullet entered the suppressor that it would wobble enough to cause a strike. I’m using the 1680 as well. I understand how temperature sensitive some rifle powders are.
     

    Flightmurse

    Sergeant of the Hide
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    Jul 30, 2018
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    I’ve never had issues with a 1:8 twist with any ammo, to include heavy cast bullets. If you are using them on game be aware that subsonic smk’s will just drill holes.