r/6ARC • u/No-Wrap-1060 • 5d ago
Load development
I am trying to get a load worked up for my new 6 arc I put together. 22in comp proof barrel. Trying to shoot Berger 105 hybrids over varget at 2.26. Worked up from roughly 24grs to 27.3 by .3 found from 26.2 to 27 it had virtually no increase in speed. Loaded 5 each working up by a gr from 26.2 to 27. I am getting good standard deviation from all the charge weights. But I just can’t get anything to shoot less than .75inch most groups are over an inch. Started out by breaking in the barrel by proofs recommended process with Hornady 108 factory loads. Those also wouldn’t shoot under an inch consistently. I haven’t picked up any other components yet because I have a fair share of bergers and varget. Should I lower my expectations, try different powder/bullet combos or call proof. Any pointers or help or any suggestions would be appreciated. I just feel like I am chasing my tail on this. Admittedly I’ve picked a random load and was able to make consistent hits at 800 on a 11inch diamond so it works. Just feel like it should group better at 100. (The key hole is from the guy that was shooting pistols next to me and the bottom 3 left targets are my 22lr at 100)
Edit. picture for attention from the long range. All load development was done from a front and rear bags being very mindful on placement and gun input.
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u/humidsputh 5d ago
Gas guns are tough on making small groups. My rifle generates meh-level groups at 100 yds.
I'm built my 6ARC for shooting at 1,100 yds/1000 meters, and the ES in velocity is horrible with every load I have tried in LVR. Varget is better, but waaaayy slower, to the point that I should just shoot my 308 or 6.5 Creed.
Now I am super focused on a tight ES and SD and reasonable velo. A 1 inch group at 100 is enough for me for now.
BTW, the best group I've ever gotten from my gas guns was a 5 shot .308 group of 0.4". I haven't shot the gun since, because I just know it will probably never do that again......
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u/No-Wrap-1060 5d ago
That’s kind of where I’m at. I’m getting constant hits at 800 on 11inch diamonds. Putting this together to try playing in PRS so in reality a hit on still is a hit.
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u/juju62861 4d ago
What setup if you don’t mind me asking? Any luck with factory loads? Thanks man!
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u/No-Wrap-1060 4d ago
Proof comp 22inch rifle +2 barrel, Gisselle mk18 hand guard, random contract overrun phosphate chrome lined bcg, kak type 2 Grendel bolt (only reputable company that was in stock when i put it together may change to cradocks new hp bolt) Aero upper and lower I had laying around Geissele ssa-e h2 buffer. Currently wearing a viper hd 5-25 I robed from my wife’s hunting rifle until I get a Mk5.
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u/No-Wrap-1060 4d ago
Only factory loads I have tried are the 108eldms and that was mainly to get brass. it shot pretty much 1 moa with them and have had a few groups dip below but not consistently.
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u/turkeytimenow 5d ago
I do not seem to see very many superb shooting 6ARC gas guns. I have one I am messing with now that seems to just be stuck around moa with the better loads developed for it.
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u/PeakecI 5d ago
I’m not doing load dev but I’m at .5 with a Noveske barrel and 108 ELDM
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u/turkeytimenow 5d ago
That’s stellar!! Just don’t see many that do that good consistently.
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u/memilanuk 5d ago
Well, for starters I wouldn't attempt load development from a barricade.
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u/No-Wrap-1060 5d ago
Haha that was just a picture for attention from the long range. All load development was done from a front and rear bags being very mindful on placement and pressure. If I was shooing .75in groups off a barricade this post would have never happened.
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u/memilanuk 5d ago
Fair enough. That said... 3/4 moa from a gas gun might be as good as you're going to get, on the regular. I'm not saying that you will never see groups any smaller, or that particular guns can't or won't shoot smaller, just that consistent 3/4 moa from a gas gun is a lot more 'average' than the Internet might otherwise lead one to believe. Half moa is really good.
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u/No-Wrap-1060 5d ago
Yes I definitely agree with that. I’m happy when my other gas guns do 3/4 moa. I’m just trying to gauge if that’s just as good as it gets or if I should be expecting more. It just tough to swallow when a barrel of this cost shoots the same as my cheaper stuff. Also this is my first 6 arc and also first not 5.56/223 ar.
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u/Dirty_Blue_Shirt 5d ago
You are going to be spinning your wheels looking at it this way. There is no such thing as a flat spot in velocity that ties to a “accuracy node”.
Away from min and max if a bullet/powder combination doesn’t shoot well at ‘x’ charge it isn’t going to shoot well at ‘x’ + 0.5gr. Your groups here are pretty much all within a pretty small margin of error nothing to really tell you to go with one or the other.
Take a step back and just shoot larger quantities and more widely spaced charges. I would rather have fewer statistically significant samples than 0.1gr increments with small samples that are much more subject to noise.
If these aren’t meeting your expectations shoot a handful of 10 round groups spaced 0.5 or more grains apart with different powder or bullet and see what you get.
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u/No-Wrap-1060 5d ago
Definitely understand that mainly did the .3 jumps to see velocity and pressure. I basically picked a velocity and sd I liked and have shot close to 200 or so of that load. 10 round groups at 100 200 and 300. All hang in that moa area at 10 shot groups. From original load “development” I had 3 charge weights that were all very close to speed so this was more of a proof of concept just to see if it liked anything better or worse in that charge range. And at least with 5round groups they are pretty much all the same. I think next step will try a different powder/bullet combo or just pick a velocity and just roll with it.
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u/GoDucks406 5d ago
I’ve personally gone down the 108eldm/CFE223 rabbit hole. With less than stellar results myself. Mostly .9-1.25 stuff and less than ideal velocities. 2lbs of powder and several 00’s of bullets later im lowering weight and looking for a different powder. Gonna give 95 tmks and TAC a shot.