bmortell
09-02-2018, 07:39 PM
today I tried paper patching my Winchester 70 300 win mag as a possible hunting load. I was using lee 170 acww boolit, I patched about 2/3 the way up the bore riding portion to a bit behind the ogive with Alvin lightweight tracing paper from amazon. then I baked em at 200 to dry, smeared some LLA on and pushed through a .3095 sizer. for reloading I FL sized 1/4 turn off and used an M die. powder charge was 26.5 sr4759 and 1 gr of pulled apart polyfill on top. I seated to 3.295 which is about how far you can push in till bearing surface would be exposed in the case.
on chambered ones the rifling makes marks on the paper about 3/16" or so down it, took 5 shots at 70yds over the chrony, shot 1.25", lowest velocity 1877, highest 1890. and these were castings set aside as minor defects, not weight sorted and some of the papers overlapped on the 2nd wrap. I thought this was great for a first try!
on chambered ones the rifling makes marks on the paper about 3/16" or so down it, took 5 shots at 70yds over the chrony, shot 1.25", lowest velocity 1877, highest 1890. and these were castings set aside as minor defects, not weight sorted and some of the papers overlapped on the 2nd wrap. I thought this was great for a first try!