way back when , i did some load development using 180s and 748 powder using a REAL m14, not a norc- 42 grains wouldn't push the rod back all the way, worked my way up to 43- still not relaiable- went to 43.9( which was virtually the same as the m118 load, but my bullet was 5 grains or more heavier) which gives supposedly about 2500 fps and it worked well- however, 44.2 was starting to give gas sign pressures, and i quit at 44.3
b/c the rifle was TELLING ME TO- the winchester factory load is SUPPOSED TO BE 2610 fps with about 45 grains- THIS IS WAY OVER PRESSURE FOR THE 14- if you believe their stats- now while we're talking norc, and this was a h&r, i feel it gives relevant data - and it was one of my isreali rifles- that just shows you EXACTLY where the pressure point is-THEN I FOUND OUT ABOUT THE 175 TOP END and have dropped back accordingly- it means having to carry two bullet weights ( 1 for the m14 and 180 for everything else) but my parts budget isn't bottomless and m14parts, even chinese, are hardly something the hardware store carries- and i'd just rather not break an op-rod,
fyi , i shoot groups of 5 when working up a load, 100 yard target, about a minute for cooling between shots and don't count the first 5 for "wet" barrel" and when the groups begin to widen or i see pressure signs, i stop- 4-12x40 scope off a bench with a sandbagged rest , or varminter's rest, or bipod if on the rifle, remington 180 grain bulk bullets, new r-p cases, cci large rifle magnum primers- cleaning every 100- once i'm there, it gets cleaned and put away and i fire 2 or 3 fouling shots before using next time