458 Socom

[JimP.]

Help, any one got any loads for the 458 Socom cartridge used in an AR-15, will be using 300 gr bullets, any help willl be greatly appreciated....tks

[Reed1911]

Jim,

Go to www.458socomforums.com Marty has listed data there as well as other 458 owners.

[JimP.]

Thank you very much didnt know bout the site, have joined now, tks, JimP.

[Reed1911]

No problem, RL7 is a good all around powder, H110 for the light stuff

[JimP.]

44.0 grs of RL7 for 1871 fps
34.0 grs of Lil gun for 1942 fps
Rifle is a DPMS lower with a Rock River Arms upper 16 inch barrel]
cases were Starline, WLP primers and Sierra 300 gr JHP bullets with an overall length of 2.02 inches, wiith a good crimp

JimP.

[Reed1911]

Jim's above was most likely done on the older run of brass, the newer stuff is thicker and 44g is a bit over pressure, just another good reason to work up your loads and not just take them from somewhere.