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Finally a heavy load that shoots well in my 5.56 RPR

This topic can be found at:
https://sigforum.com/eve/forums/a/tpc/f/630601935/m/2850056154

January 02, 2019, 05:21 PM
usncorpsman
Finally a heavy load that shoots well in my 5.56 RPR
I purchased this gun several months ago and have shot about 500 rds through it. Almost all of them have been my reloads. This gun DOES NOT LIKE ANYTHING above 69gr. It shoots light out with my Hornady 55gr FMJ reloads and even better with Hornady 55gr SP. today I re-tried my 69gr SMK loads @ 24.5gr of Varget. Previous loads were @ 23.5gr and 25gr of Varget, both of which just did OK in the gun.

Well today, I got a few really good groups at 100yds with the 24.5gr Varget. I would get 4 touching and throw one out. The gun has the potential to shoot well under 1” @ 100yd. I’ll continue to refine and work on this load.


All targets are 5 shot groups @ 100. All the flyers are my fault and not the fault of the gun.








January 02, 2019, 07:43 PM
fritz
quote:
Originally posted by usncorpsman:
This gun DOES NOT LIKE ANYTHING above 69gr.

Until recently I could not imagine a quality barrel with 1/7 twist that wouldn't accurately shoot 73-77 grain match bullets.

That changed after testing my 1/7 LWRC upper. It turned out that 69 SMK and 55 VMax bullets were the ticket, and pretty much nothing else. Very odd, compared to my other barrels, of various lengths, and of twists from 1/9 to 1/7.

69 SMK loads work well in all of my barrels -- some of the tightest groups I've produced at 100 yards. It's just too bad that the 69 SMK has only a mid-level Ballistic Coefficient.
January 02, 2019, 11:24 PM
smithnsig
I have an 18” 1/8 twist 556 chamber that shoots poorly with 73 ELD, and 77 SMK but shoots well with 75 gr Hornady, and decent with PPU 75.

I just built another upper with a 223 Wylde 1/8. Ole get some round down and see how it works with the heavies.


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