The case was made too short. It should have been extended to 6.8 SPC length. 85gr Partitions at 3100fps, 90gr Accubonds at 3025fps from an 18" AR-15.

Left to right - 6PPC, 6mm Too Short ARC, 6mm Correct Length ARC, 6.5 Grendel, 6.8 SPC.

Tony

[Linked Image from i.imgur.com]

Last edited by TonyRumore; 04/03/23.
Run it up, until you blow it up, then back it down a bit.