Good luck with the short mag's they will never run with the parent cartridges I run a browning and Winchester service center for 7 years they didn't feed or extract they started to work better when they back the loads down to 150 -200 ft under the parent cartridgesIt will, have saw it up to 2900 with RL26 @ 3.12" OAL from a 24" barrel, Bertram brass. I will attempt to achieve the same thing.