Feedback please...Mid Range AR build and Load

[CaptBeach]

I set out to build a 600 yard hammer. YHM Upper and Lower, M16 BCG with a WOA fitted bolt head to a WOA 16" heavy SDM barrel, 1:7 Wylde chamber, UBR stock, YHM Diamond Free Float rail, Geisselle SSA trigger, Wolfe springs, Burris Extreme rings and a SWFA 3x15. YHM QD Flash Suppressor and YHM 308 Suppressor (sometimes). So far it functions flawlessly but accuracy with the surplus mil M855 and M193 is crap 1.5 to 2.5", sometimes 3-4" at 100 (I can get .3-.4 with my 308 bolt gun with 308 175 FGMM clones, I'm a former 2111 Armorer, Marine Rifle Team shooter, DM contractor so I believe its not the shooter) I expected better than this and I suspect its too fast of a twist. I happened on a good deal with 500 77 gr SMK's and want to work up a load for it...I have BC2, RL15, and Varget on the shelf. I have a virtually unlimited supply of 1x LC brass. I have read that 24gr of RL 15 or Varget is the ticket for Service Rifles with this weight bullet and this twist but with 20-24" barrels. What issues will I have other than velocity drop running the 16" WOA?

Thanks

 

[gohring3006]

The twist is fine, I have good luck with Benchmark in my 1-9 twist. But I run 60 gr Vmax. Its possible your bullet doesn't like the jump to the lands. And we are limited with the mag in our AR's. We ran the 77gr in a bolt gun and they like to be jammed in that rifle.

 

[barefooter56]

I set out to build a 600 yard hammer. YHM Upper and Lower, M16 BCG with a WOA fitted bolt head to a WOA 16" heavy SDM barrel, 1:7 Wylde chamber, UBR stock, YHM Diamond Free Float rail, Geisselle SSA trigger, Wolfe springs, Burris Extreme rings and a SWFA 3x15. YHM QD Flash Suppressor and YHM 308 Suppressor (sometimes). So far it functions flawlessly but accuracy with the surplus mil M855 and M193 is crap 1.5 to 2.5", sometimes 3-4" at 100 (I can get .3-.4 with my 308 bolt gun with 308 175 FGMM clones, I'm a former 2111 Armorer, Marine Rifle Team shooter, DM contractor so I believe its not the shooter) I expected better than this and I suspect its too fast of a twist. I happened on a good deal with 500 77 gr SMK's and want to work up a load for it...I have BC2, RL15, and Varget on the shelf. I have a virtually unlimited supply of 1x LC brass. I have read that 24gr of RL 15 or Varget is the ticket for Service Rifles with this weight bullet and this twist but with 20-24" barrels. What issues will I have other than velocity drop running the 16" WOA?

Thanks

CaptBeach,
Try our 73 grain .224 bullets. These are a length tolerant bullet and work really well at magazine lengths. No issues going out to 600 yards + with these. Corey and I use them in our 3-gun ARs with IMR 8028 XBR and they shoot extremely well !

 

[CaptBeach]

Thanks guys for the input...I will see if I can find some Bergers...

 

[RO828]

I have had great luck with the 69 SMKs and Varget in my 7 twist mid range. I suspect Phil's recommendation would be solid as well. Both should feed efficiently and shoot well.

Your results with the surplus is not uncommon. I routinely see the same out of mine.

 

[Trnelson]

I have similar results with surplus ammo. Sometimes it shoots, sometimes, not so much. I have a 16" 1 in 7 twist 5.56 nato chambered upper on mine. I have good results with the Sierra 69g Matchkings, the Hornady 75g BTHP and the aforementioned Berger. A friend of mine really likes the 77g Lapua Scenar at magazine feedable lengths. YMMV.
I load mine with R-15, there are several powders that will deliver equal or even better results. Have fun, be safe