Decided to gamble on building a semi-auto rig for my primary 1k steel bang'r. Mega Ma-Ten upper/lower, 24" DPMS .925" 1:8.5 barrel, rifle length gas, JP fore end, Geisselle enhanced 2-stage, Magpul grip/buttstock, Vortex Viper PST 4-16 FFP Mrad and American defense recon 20moa mount.
Never reloaded for a semi auto rig before, I took several crash courses via search engines/etc and got things on track.
After dialing in the neck tension, groups started looking better. Tried many loads with H4350 and RL17 powders, cci primers, lapua 260 brass, redding full length, .293 s bushing
It was quite a chore getting the 139 scenars to shoot under an inch, couldn't push them past 2715fps without crater'd primers and double digit sd. Once I got the neck tension down, they did around .7 (*max mag length, 2.805 w/.04? jump to lands)
Ordered some hornady 123gr Amax bullets to try. At max mag length 2.805 they are .033 to lands, I can push them just over 2900 with no pressure signs and noticably less felt recoil/movement. The 123's are not finicky whatsoever, they group well no matter the charge or brass variables. Found the max charge of H4350 that produced velocities that don't vary more than 11fps, 43.7gr at 2905fps avg. Could get higher fps with no pressure sign, but the velocities varied more than 20fps. R17 allowed around 30-50 higher fps, but got fps that varied 15 to 40+.
Some 100yd targets, shot off the back of the rzr:
Drove the the range yesterday to stretch it out, but had a scope hiccup that left me dead in the water. When dialing elevation, the reticle would stop it's travel at a point, only allowing +4mrad of travel. Dialed the heck out of it last night, L/R, U/D and it has regained full travel again....?
139 scenars, 42gr H4350, 2715 fps
5rnds 1000yds: -8.8mil w/200yd zero
123 Amax, 43.7gr H4350, 2900 fps
5rnds 1000yds: -8.3mil w/200yd zero
thru the bushnell spotter before going downrange:
Only a few inches difference in wind hold between the two at 1k.
.
Gonna stick with the 123's, less fussy, cheaper and easier to drive. Might try the 140's for the hell of it some day.
Never reloaded for a semi auto rig before, I took several crash courses via search engines/etc and got things on track.
After dialing in the neck tension, groups started looking better. Tried many loads with H4350 and RL17 powders, cci primers, lapua 260 brass, redding full length, .293 s bushing
It was quite a chore getting the 139 scenars to shoot under an inch, couldn't push them past 2715fps without crater'd primers and double digit sd. Once I got the neck tension down, they did around .7 (*max mag length, 2.805 w/.04? jump to lands)
Ordered some hornady 123gr Amax bullets to try. At max mag length 2.805 they are .033 to lands, I can push them just over 2900 with no pressure signs and noticably less felt recoil/movement. The 123's are not finicky whatsoever, they group well no matter the charge or brass variables. Found the max charge of H4350 that produced velocities that don't vary more than 11fps, 43.7gr at 2905fps avg. Could get higher fps with no pressure sign, but the velocities varied more than 20fps. R17 allowed around 30-50 higher fps, but got fps that varied 15 to 40+.
Some 100yd targets, shot off the back of the rzr:
Drove the the range yesterday to stretch it out, but had a scope hiccup that left me dead in the water. When dialing elevation, the reticle would stop it's travel at a point, only allowing +4mrad of travel. Dialed the heck out of it last night, L/R, U/D and it has regained full travel again....?
139 scenars, 42gr H4350, 2715 fps
5rnds 1000yds: -8.8mil w/200yd zero
123 Amax, 43.7gr H4350, 2900 fps
5rnds 1000yds: -8.3mil w/200yd zero
thru the bushnell spotter before going downrange:
Only a few inches difference in wind hold between the two at 1k.
.
Gonna stick with the 123's, less fussy, cheaper and easier to drive. Might try the 140's for the hell of it some day.
