Searching for accuracy from a LWRC M6 SPR

[EchoDeltaSierra]

I had an opportunity to sell my SPR (concept build) and purchase a replacement. My previous rifle was a Ruger SR-556e and I was really happy with it's performance and accuracy. I was at the range with a couple of friends and one of them made me an offer I just couldn't refuse. I went with the LWRC because I wanted a piston gun (for a few key reasons) in my carbine length system and I also wanted a tighter twist barrel (1/7").

Now I'm back to the drawing board to find what it likes to shoot best. If any of you are shooting LWRCs, I'm curious what grain weight bullets you are finding produces best accuracy. My initial testing, with available ammo on a new barrel, shows it does pretty well with 55 gr., not so much with 62 gr. green tip, and noticeably better with 77 gr.

Thanks in advance.

 

[samnev]

I have never had any luck with accuracy with the 62 grain green tip projo's in any of my ar's. But the 69 grain SMK's and surprisingly the 52 grain SMK's shot really well.

 

[EchoDeltaSierra]

I have never had any luck with accuracy with the 62 grain green tip projo's in any of my ar's. But the 69 grain SMK's and surprisingly the 52 grain SMK's shot really well.

What velocity are you running the 52 gr. at? I thought less than 55 gr. could be problematic in 1:7" barrels. I'd love to find a light fast, flat and accurate load for prairie dogs.

Also, maybe this would have been better suited for the reloading thread.

 

[samnev]

What velocity are you running the 52 gr. at? I thought less than 55 gr. could be problematic in 1:7" barrels. I'd love to find a light fast, flat and accurate load for prairie dogs.

Also, maybe this would have been better suited for the reloading thread.

The reason the 52 grain SMK's shoot well I believe is that they have a much longer profile than the 55 grain projo's and possibly the construction. I had been using this load in my Remington 223 PSS (1:9 twist) for years and always shot just over 0.5 moa 100 yard 5 shot groups. I bought a SIG 556 when the first came out and accuracy was mediocre at best with the heavier projo's one would usually shoot in a 1:7 twist barrel. Out of frustration I decided to give the 52 grain SMK's I had loaded for my PSS a try. To my suppress the 100 yard 5 shot groups were just over 1 moa when I had been getting 2-3 moa groups with the heavier projos up to the 69 grain SMK's. Since then I have shot nothing else in my AR 15 platforms. My RRA's, Noveske's, POF 415, Sig 516, S&W MP 15FT and Colt's (6721 Enhanced and 6920) all shoot under 1 moa most closer to 0.75 or less especially the Noveske N4 Afghan's and the RRA's. The load that I use is 26.2 grains of W748 and the 52 grain SMK's. I don't have a chromo but IIRC the velocity is somewhere around 2900 fps.

Your probably right about it being on the reloading board but I just answered the post that was on this board. If the moderators wish they are free to move it there.

 

[FN in MT]

LWRC M6A2 with a 16" barrel; 68 Hornady/69 gr Sierra MK, 25.3 VARGET, RP 7 1/2, set to max OCL allowed by magazine...sub MOA consistently.

It also likes the Black Hills 75 and 77 gr Match ammo too.

Add me to the group that has gotten shitty to horrible accuracy with the 62 gr green tip.

 

[VKC]

I just shoot PMC 55gr from my LWRCs and the accuracy is great, around 3/4 MOA.

 

[ZLBubba]

I've had much better luck with the 75gr Hornadys and the 77gr SMKs. I avoid the 62gr green tips like the plague. They don't shoot well and just not worth the effort to me.