10.5 inch bbl questions
I'm planing on a 10.5 inch bbl 5.56 upper. A couple of questions:
1. Is that too short to put a high quality (Surefire 6.8mm) suppressor on?
2. What twist rate would you recommend? I usually like 1/7 twist rates for 16 inch barrels, to stabalize 70+ grain bullets. But are those too slow out of a 10.5 inch barrel to use anyway? If you're using 55 or 62 grain bullets to get decent velocity, then is 1/9 a better twist?
Thanks,
For a 10.5" barrel, a 1/7 twist would be better than a 1/9. The 1/9's are better with 20+ inch barrels,imo.(if you are wanting to shoot anything in the 68gr+ catagory). My 10.5" is 1/7 and does well with anything from 55gr to 70gr(haven't tested anything heavier yet)
With a suppressor ..you are in slightly different territory and may be looking to go with heavier bullets anyway, so a 1/7 is better suited. Just my thoughts, I could be off base, so take it for what it's worth.
Not too short
1/7 or 1/8 are ideal
Originally Posted By Friendly_Crusader:
Not too short
1/7 or 1/8 are ideal
this.
Damn, I should have asked this question before having my dealer order a 1/9. I went solely on the 55gr ammo I always shoot.
I wouldn't worry about it.
When the time comes, you should always test fire a group or two on paper to make sure your not key holeing on that new upper.
If everything looks OK, attach the can, and have some fun!
The reason you should check it out on paper is, what if you got a bad barrel or something? I'd hate to damage my silencer.....
I just dropped paperwork for an SBR lower and currently sourcing parts for the 10.5" that will sit on it. I plan on running my YHM phantom QD can with it and everywhere I read (including my C3 dealer) says to use a brake instead of a flash hider if you want to not ruin your can prematurely. We will definetly speed up the wear process of our cans, but YHM guarantees thier cans to out live the host firearm, my .30cal can is rated up to .300 win mag, rated full auto, and anything greater than 10.3" bbl length. Sounds good to me. The purpose of the brake instead of the FH is to add additional pre-baffles before hitting the first blast baffle of the suppressor. A $70 muzzle device is a hell of a lot easier to replace than a $800 suppressor, $200 tax stamp, and 5 months.
A 7 twist 10.5 will get the bullet 1 full revolution before exiting since the chamber isn't counted in twist rate. Your best MFGs use 7 twist barrels: LMT, BCM, Noveske, Daniel Defense, Colt...they know what they're doing when it comes to making good barrels.
A 9 twist won't get that bullet to one full revolution but still may stabilize lighter grain ammunition––-55 to 62gr would be the ideal.
Originally Posted By LMTRocks:
A 7 twist 10.5 will get the bullet 1 full revolution before exiting since the chamber isn't counted in twist rate. Your best MFGs use 7 twist barrels: LMT, BCM, Noveske, Daniel Defense, Colt...they know what they're doing when it comes to making good barrels.
A 9 twist won't get that bullet to one full revolution but still may stabilize lighter grain ammunition––-55 to 62gr would be the ideal.
I buy wolf buy the case and its always 55gr, I should be ok then. The reason I went with a 1/9 was because I also have a .22LR conversion I use with it and I didn't think it would stabilize with the 7 twist.
