GaCop
08-01-2020, 07:12 AM
Back in May I built my Bushmaster on what was originally a 243 Axis XP. Got the barrel from Rhineland and it's a fantastic shooter. It their 16 inch with the 1/16" twist. From day one, no copper fouling at all and cast bullets leave the bore looking like it was never fired.
Load development has been ongoing with both Jacketed and cast bullets from 200 grain cast and jacketed right up to 400 and 405 grain cast and jacketed. Being the cheapskate that I am, I experimented with resized .458" bullets. Cast are coming in at .453/.454" and Jacketed are coming in at .453". Jacketed bullets are Hornady 200, 250 XTP and 300 gr XTP Mag in .452". The resized bullets were first run through a Lee .454 sizer and then the .452 and are in weights of 300, 350 and 400 grain Hornady and Speer. Brass has been mostly Hornady with a Smattering of Starline. Primers used have been CCI 400 and 450, Wolf Mag SR and Rem 7 1/2. The worst shooting bullets have been the lighter 200 grain cast meant for the 45 Colt. Best to date, with the 400 grain Speer has been with Reloader 10 giving 1.3" groups at 100 yards. Powders used have been (for light cast loads) Unique and IMR 4227. Lil Gun has been an excellent performer with the 250 XTP and 300 grain XTP-Mag. The heavier jacketed bullets are showing promise with Reloader 7 and 10. A1680 and 5744 are said to be good powders for the Bushmaster but, around here, it's made from "unobtanium".
The magazine has been a bit of a pain feeding flat nose bullets, the mouth of the chamber hangs on the front edge of the mag even though I modified the follower, installed a 1/2" spacer in the rear of the mag and lowered the front of the mag with a Dremel. 250 grain XTPs, 405 grain Cast RNFP and Speer JRN feed great. The 400 grain JSP is a real shoulder thumber at more than 1600 fps and muzzle energy of 2300 ft/lbs.
Load development has been ongoing with both Jacketed and cast bullets from 200 grain cast and jacketed right up to 400 and 405 grain cast and jacketed. Being the cheapskate that I am, I experimented with resized .458" bullets. Cast are coming in at .453/.454" and Jacketed are coming in at .453". Jacketed bullets are Hornady 200, 250 XTP and 300 gr XTP Mag in .452". The resized bullets were first run through a Lee .454 sizer and then the .452 and are in weights of 300, 350 and 400 grain Hornady and Speer. Brass has been mostly Hornady with a Smattering of Starline. Primers used have been CCI 400 and 450, Wolf Mag SR and Rem 7 1/2. The worst shooting bullets have been the lighter 200 grain cast meant for the 45 Colt. Best to date, with the 400 grain Speer has been with Reloader 10 giving 1.3" groups at 100 yards. Powders used have been (for light cast loads) Unique and IMR 4227. Lil Gun has been an excellent performer with the 250 XTP and 300 grain XTP-Mag. The heavier jacketed bullets are showing promise with Reloader 7 and 10. A1680 and 5744 are said to be good powders for the Bushmaster but, around here, it's made from "unobtanium".
The magazine has been a bit of a pain feeding flat nose bullets, the mouth of the chamber hangs on the front edge of the mag even though I modified the follower, installed a 1/2" spacer in the rear of the mag and lowered the front of the mag with a Dremel. 250 grain XTPs, 405 grain Cast RNFP and Speer JRN feed great. The 400 grain JSP is a real shoulder thumber at more than 1600 fps and muzzle energy of 2300 ft/lbs.