For years I have been a bolt collector and reloader, and have enjoyed it very much. A few months ago I decided to get two things that I did not have, a 450 Bushmaster because I wanted to have something other that a muzzleloader to hunt with my brother in southern MI, and an AR version rather than bolt action. Figured it was about time to start learning something new, so my purchase was the Ruger AR-556 MPR Model 8522 and added one of my favorite scopes, a Vortex Crossfire 4-12X44. Needless to say I was pretty excited, like a kid with his first Daisey BB gun. The specs for the AR is as follows -
Barrel Length - 18.63"
Twist Rate - 1:16" RH
Grooves - 5
I bought Hornady Black 250 FTX factory rounds to start things of with, and was impressed with the groups at 100 & 200 yards. The other thing that was different from the specs on the box was the drop from 100 to 200 was 6" not 4.1. Which made me wonder if I was really getting 2200 fps out of them as stated, and as a reloader figured it should not be hard to improve on that.
The 2 bullets I have purchased to use is the Hornady 250gr FTX, as I would like to try and improve on the factory rounds. The other bullet is the Barnes 200gr XPB. I have all kinds of reloading manuals, but have always looked at them from a bolt action perspective. And I never assume I know it all, so a little help please. Loading for an AR is different than a bolt action, correct? The main difference I am reading is in pressures? I know from my limited time on this site, there are some very seasoned AR & bolt users of the 450BM and would like to hear your thoughts.
The reason I decided to inquire about some references rather than just load and try, is the expense of these. Quite different than buying a box of .243 to send down range. If you own this AR or another AR with similar specs and have found a load for these 2 bullets, I would appreciate hearing from you.
Thanks,
michtech