Rifle barrel is a CBI 260 Rem Match (longer freebore). I realize now I probably didn't need the longer freebore as I am running mag length.
Using the Hornady OAL tool. Hornady 140 Amax: lands at 2.3390 (ogive using the .25 comparator as I apparently don't have a 26 one, but getting consistent readings). Sierra 142 MK: lands at 2.3530.
My OAL for the 140 Amax at .02 off the lands works out to be 2.8980. Mag Length is 2.860 and that is pushing it. If I load the Amax at 2.850 (0.01 short of mag length), I am about 0.065 off the lands. From my reading, the Amax likes to be 0.02 off the lands.
My OAL for the 142 SMK at .02 off the lands works out to be 2.8770. If I load the SMK at 2.850 (0.01 short of mag length), I am about 0.05 off the lands. From my reading, the SMK likes to be 0.02 off the lands.
I did run a set of ladders from 41.9 to 43.1 (.3 increments) at mag length for both and I was at more than 1 MOA accuracy and that is a far cry from what I had expected.
I would like to try the following as long as it does not sound completely off base. I will rerun my ladders at 0.02 off the lands for both the 140 Amax and the 142 SMK. These will be single fed and I will hopefully come up with a fairly accurate load. Once that charge weight is determined, run another set of ladders varying the OAL to see if there is an OAL that can be mag fed that is still as accurate.
Thoughts?
Using the Hornady OAL tool. Hornady 140 Amax: lands at 2.3390 (ogive using the .25 comparator as I apparently don't have a 26 one, but getting consistent readings). Sierra 142 MK: lands at 2.3530.
My OAL for the 140 Amax at .02 off the lands works out to be 2.8980. Mag Length is 2.860 and that is pushing it. If I load the Amax at 2.850 (0.01 short of mag length), I am about 0.065 off the lands. From my reading, the Amax likes to be 0.02 off the lands.
My OAL for the 142 SMK at .02 off the lands works out to be 2.8770. If I load the SMK at 2.850 (0.01 short of mag length), I am about 0.05 off the lands. From my reading, the SMK likes to be 0.02 off the lands.
I did run a set of ladders from 41.9 to 43.1 (.3 increments) at mag length for both and I was at more than 1 MOA accuracy and that is a far cry from what I had expected.
I would like to try the following as long as it does not sound completely off base. I will rerun my ladders at 0.02 off the lands for both the 140 Amax and the 142 SMK. These will be single fed and I will hopefully come up with a fairly accurate load. Once that charge weight is determined, run another set of ladders varying the OAL to see if there is an OAL that can be mag fed that is still as accurate.
Thoughts?