New to the forum, AR's, and to reloading. Read some where that was a crazy thing to do, but I'm having fun. I've got a 24" 264 LBC super varmint. I loaded some 120 balistic tips with 2520 the groups were ok, maybe changing COL would help me. At29.9 gr up to 30.6 gr (the top load listed on the AA load data) the action seemed to work a lot harder, cases were landing 6 - 10 ft between 3 and 5, so straight out to slightly back. Primers looked ok, no Case head swipe (brass extrusion), but I couldn't tell if the bolt carrier was bottoming out or hammering the action.
Are there any tell tale signs if the bolt carrier is bottoming out?
I'm going to buy some more factory AA ammo and try to figure out how to set up my cronograph to check velocities of factory vs handloads. Going to practice with the crono using an air rifle at home so I don't waste alot of ammo. Annoying thing is most of the lights in my basement are flourescent so I have to set up some incandescents and turn the other off.
Reply from LRRPF52:
What buffer are you using? You'll have a lot more dwell time with that 24", and 120's over 28.5gr of 2520 will feel somewhat hefty if you have a standard carbine buffer. I'm not sure what buffer/recoil spring/bolt carrier weights you have. They should be on the heavier side with the Grendel, especially with 120+ gr bullets and stiff loads.
The super varmint comes with a standard A2 stock with rifle buffer and spring. I did cursory search and I thought rifle buffers only came in one weight. I could try a stiffer spring I guess. It may take me a month or more to find the time to figure out the crono and then start low and work my way up again checking velocities. I would rather not blow a primer or damage the rifle or myself.
Are there any tell tale signs if the bolt carrier is bottoming out?
I'm going to buy some more factory AA ammo and try to figure out how to set up my cronograph to check velocities of factory vs handloads. Going to practice with the crono using an air rifle at home so I don't waste alot of ammo. Annoying thing is most of the lights in my basement are flourescent so I have to set up some incandescents and turn the other off.
Reply from LRRPF52:
What buffer are you using? You'll have a lot more dwell time with that 24", and 120's over 28.5gr of 2520 will feel somewhat hefty if you have a standard carbine buffer. I'm not sure what buffer/recoil spring/bolt carrier weights you have. They should be on the heavier side with the Grendel, especially with 120+ gr bullets and stiff loads.
The super varmint comes with a standard A2 stock with rifle buffer and spring. I did cursory search and I thought rifle buffers only came in one weight. I could try a stiffer spring I guess. It may take me a month or more to find the time to figure out the crono and then start low and work my way up again checking velocities. I would rather not blow a primer or damage the rifle or myself.
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