6.8 loading question?

[Chuckdog]

I have a friend with a 6.8 that we've been shooting, trying different loads in. The rifle shot great with my loads when I installed and zeroed the scope. We have yet to find one of his loads that shoots under 3" or 4". He's an older guy that been handloading for years, but he's new to the AR platform. He was about to convince himself that something is wrong with his rifle. I gave him my exact load data, and we both shot 4" groups with it. I brought some of my handloads Friday and the first 5 shot group was 1.130, with 1 shooter induced flyer that ruined what was .70" for the other 4. I let the barrel cool and shot another 3 shot group that measured just over .80". There's definitely nothing wrong with his rifle. All his components are the same as mine. He's had zero function issues. I'm going to look at his setup this week, to see if something die wise doesn't look right. Do any of you have any ideas? My go to load is 110gr Sierras with 29grs of H322. My Stag will print 5 shot groups under an inch every time I do my part. His will too, if I load them?

 

[Gun Guru]

I gotta think there's something wrong with his loading. Maybe a bad batch of powder? Could be the powder has been sitting around for a while. I know I have some that's very old. But I still use it. Hope you find a simple solution.

 

[AR-Trvlr]

Have you looked at the overall length? If the lengths are significantly different that could have a huge impact.

 

[Chuckdog]

That's one thing I asked him about. He said it was new brass, and he didn't check the case length before loading it. I did verify that he had FL sized before loading. The case length was about the only thing left that I could think of other than maybe primers. I've never had primers make that big of a difference, but he may have had them a long time. The overall length maybe an issue, but when loading the mags I haven't noticed any that looked short, and if they're long they ain't going in the mag. I need to get my chrony to the range when we go next time too. He's outta town with the muzzle loader today, so I'll follow up when I can. Thanks' for the suggestions, Chuckdog.

 

[AR-Trvlr]

I wasn't thinking of the case length so much but the overall length - how deeply the bullet is seated in the case.

Depending on how the rifle is chambered it could have a long throat - the length between the end of the case and where the rifling starts. If the bullet is seated deep into the case & has a long 'jump' between the case & the rifling that can contribute to poor accuracy. If the bullet is seated shallow in the case it can jam into the rifling & cause excessive pressure.

 

[Chuckdog]

Yeah, I saw you were talking about overall length. As stated above when I loaded the mags none appeared short, and if they're loaded long they ain't going in the mag. The overall cartridge length is a part of the data I gave him. I'm curious about case length maybe being long on his cases affecting the chamber pressures. He's an old turnbolt fellow, and him not at least checking the case length before loading makes me want to look there first. Maybe long enough to kill accuracy without interfering with reliability. It'll turn up. What I lack in talent, I make up for with doggedness. I'll worry it into submission.

 

[montana bob]

just a thought.What kind of scale. Digital or balance beam. I sent one digital back to Cabelas because I kept getting differant readings when I empty the powder out of the same cartridge I just dumped it into.My RCBS digital will continue to climb if I don't set the empty bowl back on the scale and let it return to zero everytime. I know other folks who have had the same issue with it climbing.But I wouldn't think a grain or so differance if loaded on the lighter side would have a spread of 3-4 inches at 100 yards. Just a thought.

 

[Chuckdog]

Yea, there's something weird. He's still out of town. He uses a Lyman electronic measure/scale. He's good to let it warm up and calibrate it. I helped him with it when he first got it. It may be the culprit, the thing is though he hasn't had issues with any of his other loads. I think maybe the brass is to long, or the dies aren't adjusted properly. I've loaded a lot more bottlenecks for turnbolts myself, and I know he hasn't loaded bottlenecks for selfloaders much either. That has me thinking it's more of a case prep issue. I'll update as I figure things out. Thanks' again for the post. Chuckdog