Me and a friend have built 6 arc ar's. And knowing that the pressure is lower on the gas guns, followed some Hornady and other published load data. Problem is, that by the time we reach even mid level loads in any given bullet weight, the brass is taking such a beating, or producing a "belt" on the base of the case, they are not reloadable. We each have a 24" bbl of the same mfg, and he has a second different mfg. Both of these bbls are from reputable mfg's, so just curious what others are seeing on CFE,Leverevoloution , RL 15, or any powder, with 95gr Bergers, 105 Bergers or Hornady, or 108 ELD-M bullets....Thanks for any help or advice... rsbhunter
6mm ARC "sane" loads ?
- Thread starter rsbhunter
- Start date
I would recommend cutting back the gas to the bolt as it is opening way to soon. An adjustable gas block will fix 90% of those issue. I shoot wildcats that are just flat out hot on the AR platform and pulling that gas down makes them much more manageable and doesn't trash brass. I also load to book max in my AR's on regular SAAMI stuff and have no issues.
Greg
Greg
Do have a Seekin's adj gas block, set to just lock bolt back, also have rifle length buffer with 2 tungsten (other steel) weights and a heavy spring. using good parts, Rubber city bolt, Aero enhanced upper, etc. Just has me wondering if others have similar results ? Thanks for the response , rsbhunter
I didn't anneal the new brass , this was all new , unfired, formed brass.Base to datum was set .003 off of fired factory brass measurements using Hornady comparator and .350 insert, bullets .020 off touch. Fired other loads and no scratches at all. Yes, those are cracks ! The feed ramps were polished with Dremel polishing compound and a "bullet" tip polishing tip....mirror finish, smooth edges, corners. Fired 40 rnds of factory Hornady Black....slight pressure signs, but no scratches, cracks, etc. ???? rsbhunter
So, the catastrophic case failure only has occurred with brass that you have formed?
The new brass is Starline brass, haven't tried reloading the Hornady factory Black cases yet, but have annealed, trimmed, prepped cases....was using Leverevoloution, CFE223, and Varget. I will try RL15, H4895, and Vihtavouri N133 with lighter 85 & 95gr bullets....if it will go fast enough to shoot at 500 meters and knock over a 8" x10" steel plate, I'll keep it....if not , onward and upward....rsbhunter
I annealed the new brass before setting the shoulder back and had no problems, they are on the 4th firing now
Kurz, I printed this chart....if I loaded the 109's at 31gr, I'd be picking metal shards out of my face. I've researched all the load data I can.....it seems like some rifles will shoot those loads, some won't....both my friends show pressure wreck brass at 26gr of Leverevoloution and 105's....plus, in the chart, I'm wondering if those aren't bolt gun loads...might have to drop down to 58-75gr bullets and just use it for coyotes..rsbhunter
Ned Ludd
Silver $$ Contributor
The Starline .223 Rem and .30-06 brass I have used in the past is hard as nails straight out of the box, I mean, stupidly hard. Hard goes hand-in-hand with brittle, so annealing that brass before use might be a worthwhile effort. I cannot guarantee that annealing the brass will solve 100% of your problems, but it might be a step in the right direction.
I will from here on out...I did have one case that I could not seat a bullet into...1st time, started to collapse the case...annealed the next and second time , bullet seated, but with more seat pressure than other cases. I have used Star line cases before and not had problems... Guess things have changed....or, maybe I stick with Lapua...any more, there almost the same cost.....rsbhunter
I'm curious whether you have shot any of the factory Hornady 108gr ELD-M loads in your 6mm ARC?
Some report these to show pressure.
My personal experience is that they shoot without issue. In fact, 2743 fps and sub 0.75 MOA (hard to beat with handloads). To me, I think it helps to set a baseline for performance with factory ammo that is loaded to 52K PSI pressures. If your AR shoots with pressure signs with this ammo it may be a dwell time issue related to gas, premature bolt opening, mass, spring or other timing related issue with your rifle. Mine is a 24" bbl, 1:7.5 twist, with +2 gas and a Superlative adj gas block.
Some report these to show pressure.
My personal experience is that they shoot without issue. In fact, 2743 fps and sub 0.75 MOA (hard to beat with handloads). To me, I think it helps to set a baseline for performance with factory ammo that is loaded to 52K PSI pressures. If your AR shoots with pressure signs with this ammo it may be a dwell time issue related to gas, premature bolt opening, mass, spring or other timing related issue with your rifle. Mine is a 24" bbl, 1:7.5 twist, with +2 gas and a Superlative adj gas block.
I haven't shot any of the "match" ammo..but my friend did in the matching bbl. He said it was one and done on the brass. Primer pockets gone, belt on bottom of case IF he tried to resize.....I have just accepted that 28.0 to 28.5 as max with a 105gr. I think I've accepted the limitations of the cartridge.....it will work for what I need...rsbhunter
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