I'm getting decent 4 shot groups right around 1" at 100 yards with 69gr Sierra match kings with OAL of 2.250. Do you think I would see a improvement going to say 2.255 or 2.260 (Mag length)? If it matters my barrel is a 16" ballistic advantage 223 wylde stainless steel Hanson barrel 1/8 twist. Life goal for me would be under a 1". Any tips would be great appreciated. Thanks folks.
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In my somewhat limited expierance with the 69gr SMK's in a 223Rem chamber,1:8 twist . . . the accuracy was dependent on the seating depth (how far off the lands).
I finally got the combo to shoot <MOA and as much as I can remember was about .800-.875" @ 100yds. I do remember that I had to move the bullet as fast as possible though.
I'm sure that there are more people around with better knowledge of this combo. --- SAWMAN
Thanks. With a AR your limited to max 2.260 per Mag length but wasn't sure if it would help or not.Sent from my SM-N910V using TapatalkQuote:
Originally Posted by SAWMAN
Honestly, I've struggled with these as well. Even had some keyhole on me. Couldn't get good groups no matter what I tried. This was out of a M&P with a 1:9 twist 16" barrel. It just prefers lighter grain bullets. I still have some of these Sierra's left. I'll load another test batch up at 2.260 and see if that improves anything...Quote:
Originally Posted by Guns4545
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My expierance is that the 69gr SMK's will partially destabilize using a 1:9 bbl. No matter what the "formula" sez.
I have a buddy with a bolt gun that has been rebarreled to 1:6.25 and they shoot great out of it. Should mention that it is a 223Rem chamber. --- SAWMAN
That's pretty much what I figured. My 1:9 definitely favors lighter bullets. It was worth a shot. [emoji6]Quote:
Originally Posted by SAWMAN
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If you want to try slightly longer OAL, get you some ASC mags. They guarantee a Max OAL of 2.316" but both of mine are 2.327. The 10rd are around $15 and the 20,30,40 Rd aren't much more. They are made with SS so walls are thinner and stronger. Also their follower is the best I've ever used.
With 1:9 barrel the heaviest bullet that I will use is a 62gr with lead makeup and 55gr no lead makeup.
My XM177E2 will not stabilize a M855 62gr. It has a 1:12 bbl. Found this out the hard way in 1970.
I am a huge fan of fast(er) twist bbls. Nowadays I have no .224" bore guns that do not have a 1:7 twist,the exception is the above mentioned retro build.
I have no use for a 308Win with anything but a 1:10 twist bbl. A 1:9 would be better. I do not believe that you can overspin a bullet. 350,000RPM is doable. A half million and higher with the right bullet. Example: I have a Bison Armory 18" 6.8SPCII. It came with a 1:11.25 twist bbl. They also offer a 1:7 twist bbl so you can shoot long/heavy bullets subsonic. You can also shoot lighter supers from this bbl with great accuracy. The bullets will not come apart,explode,melt,go into outter space,etc,etc. 11.25 vs 7 . . . that is a big difference.
The above are my beliefs. YMMV --- SAWMAN
My Barrel is 1:8 twist and shoots them well, but just was wondering if increasing the length will help. Guess I'll load some up and find out. 1" groups is good IMO, but wanted to see if I could do any better. I'll post how it works out as soon as I test them.
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[emoji106]Quote:
Originally Posted by Guns4545
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