Today I went out and shot from 41.5-43.5 grains of H4350. Hornady brass, 130 grain ELD-M.
All groups were 5 rounds thru a bartlein 5R, 8 twist, 18” barrel on a G2 gas gun.
41.5= 2.267”
41.7= 2.746”
42.0= 1.556”
42.3= 0.556”
42.6= 1.247”
42.9= 1.114” (4 in 1 ragged hole at 0.433”) and then a pulled shot.
43.2= 0.948”
43.5= split case. I stopped after this happened. I have been watching for pressure signs and didn’t see any before this. I did not shoot any more after the first round for fear of damaging my barrel. Once I got home I used a bent paper clip to check all the previous brass for any rings and didn’t find any even on the 43.2 load. I also looked inside the brass with a flashlight and didn’t see anything out of the norm. After looking all the brass over, I just might go back and shoot the 43.5 grain load as I feel it was a bad piece of brass. I have lost track of how many firings I have on this brass. However, I’m predicting that as long as everything looks good, that I may actually find another accuracy node. First node was at 42.3, second was 0.6 higher at 42.9, and it appears that the group is shrinking again for another node 0.6 higher at the 43.5.
Even if I can’t find another node, I don’t plan on going any higher that 43.5 I will reshoot the 42.3, 42.9, and 43.5 to test them against each other. I may play with setting depth later, but right now I want it to reliably feed from magpul M110 mags.
All groups were 5 rounds thru a bartlein 5R, 8 twist, 18” barrel on a G2 gas gun.
41.5= 2.267”
41.7= 2.746”
42.0= 1.556”
42.3= 0.556”
42.6= 1.247”
42.9= 1.114” (4 in 1 ragged hole at 0.433”) and then a pulled shot.
43.2= 0.948”
43.5= split case. I stopped after this happened. I have been watching for pressure signs and didn’t see any before this. I did not shoot any more after the first round for fear of damaging my barrel. Once I got home I used a bent paper clip to check all the previous brass for any rings and didn’t find any even on the 43.2 load. I also looked inside the brass with a flashlight and didn’t see anything out of the norm. After looking all the brass over, I just might go back and shoot the 43.5 grain load as I feel it was a bad piece of brass. I have lost track of how many firings I have on this brass. However, I’m predicting that as long as everything looks good, that I may actually find another accuracy node. First node was at 42.3, second was 0.6 higher at 42.9, and it appears that the group is shrinking again for another node 0.6 higher at the 43.5.
Even if I can’t find another node, I don’t plan on going any higher that 43.5 I will reshoot the 42.3, 42.9, and 43.5 to test them against each other. I may play with setting depth later, but right now I want it to reliably feed from magpul M110 mags.
