low power loads

[dadajack]

anyone know of definitive evidence, backed by actual tests, one way or the other? Not range anecdotes.

All the warnings in the reloading manuals were good enough for me. That, and the stories from old timers who had the bright idea to make some "summer loads" for their 270 with half a case full of powder who blew cases apart inside their actions, or destroyed the guns entirely.

I don't really have any throw away guns to prove that underloading rifle cartridges is dangerous, or I'd be happy to prove it. Again, I think it has already been established, and that's why the warnings from the people who make and test powders on a daily basis are good enough for me.

[MislMan]

Unlike most folks here I shoot a low power load in my RPR 6.5. I shoot 37.7 gr. Of H4350 at 2490 fps muzzle velocity. My SD is 11-16 depending on how often I check it. This is using Hornady brass, CCI primers and Hornady 140 gr. BTHP bullets at magazine length of 2.810 in stock Ruger barrel. Rifle has 1388 rounds down the barrel and an overall 3-shot average group of 0.426 and a 5-shot average group of 0.811" over the entire 1388 rounds. This data includes all shots from the very start of my rifle shooting endeavour up to yesterday. All different loads, bullets, rests, experiments, whatever. I have only  shot this rifle at 100 & 200 yards (95% at 100) while learning my shooting technique up to now. I am preparing to buy a new barrel (X-mas present) and start working my distance out to 600 yards with increased loads for @2700 fps.  I have shot factory  Hornady loads (2710 fps) to get brass for handloading and can't say that I noticed much if any difference in recoil. I believe Hornady ( or was that Hodgdon) shows 36.0 gr. Of H4350 as a minimum load for H4350 with 140 gr. Bullets so my load is above minimum. I went down to 37.5 gr but groups got bigger so I went back to 37.7.  Just another data point for you to consider.