Lindenwood
01-22-2015, 09:34 PM
Disclaimer: This is all unpublished data, so use at your own risk. I derived this starting data based on positive results of my own previous development and the experiences of others. Everything that follows is imaginary.......
Based on previous experience with IMR 4320 in reduced .308 loads, I started at 35gr with these 110gr RN bullets and that is at the very bottom end of cycling. All shots were fired prone with a bipod and no other support, sighting with a 1x prismatic optic (basically the etched-lens version of a red dot because my eyes suck too bad for much precision with holographic dots). All targets were blank paper because I normally shoot at 100 yards and generally can't see anything on the paper from that distance anyways. All rounds were fed from PMags. As a baseline, today I shot two 5-shot groups with 168gr AMax handloads at 100 yards and got 1.0 and 1.3 MOA.
When loaded on the shorter end (about .22" of the bullet in the case), 9 out of 10 rounds cycled, with one stoppage during feeding and no lock-open on the last round. Accuracy wasn't great. Averaged 1821fps with a large ES.
When loaded longer (about .15" into the case neck) over the same charge, groups shrank to 1.15 and 1.3", but with the slightly reduced pressure I think only one round cycled the action. Average velocity was 1801fps, with an ES of 95fps.
I also tried 20 rounds with 20gr of Unique (having worked up to that level with 150gr FMJBT with excellent accuracy), with 10 each loaded long and short as outlined above. Velocity was 2242fps, ES 25fps. Accuracy did not change between the two seating depths, staying around 1.7" for all four groups with 5 shots each at 50 yards. FYI, even at this charge the case necks were still a little sooty and primers were slightly rounder than starting-level published loads that I normally run. However, I haven't had much motivation to push any further with this powder.
At least from the prone position, I think 37 or 38gr should reliably cycle it. I'd expect about 2100fps. I'd probably run 39-40gr for increased reliability if I was planning on any offhand shooting with this load.
The wife will definitely love this setup. The one time she shot the rifle she did quite well for her first time shooting a rifle for any sort of precision (~3moa with this rifle and optic, prone) since her only other long gun experience was one time out with a Hi Point .45 Carbine. She enjoyed this a lot, but the recoil wore her out after a few groups (as I expected). But, since she got off to a good start and expressed an interest in working to improve, I have been working on reduced loads with what I have available, with a secondary goal of finding one that will also cycle the action. These are the first jacketed bullets that have shot accurately over significantly-reduced loads that still cycle (say, at least 40% reduction in recoil over standard loads). Unique has generally done well for accuracy, low recoil, and especially a mild report, but obviously doesn't cycle.
As a side note, I tried out some 135gr FP cast bullets from Badman over Unique powder (8 and 9gr) with pretty good results. 10 Rounds into 2" at 50 yards and about 1240fps, with 9gr of Unique under Dacron filler.
Based on previous experience with IMR 4320 in reduced .308 loads, I started at 35gr with these 110gr RN bullets and that is at the very bottom end of cycling. All shots were fired prone with a bipod and no other support, sighting with a 1x prismatic optic (basically the etched-lens version of a red dot because my eyes suck too bad for much precision with holographic dots). All targets were blank paper because I normally shoot at 100 yards and generally can't see anything on the paper from that distance anyways. All rounds were fed from PMags. As a baseline, today I shot two 5-shot groups with 168gr AMax handloads at 100 yards and got 1.0 and 1.3 MOA.
When loaded on the shorter end (about .22" of the bullet in the case), 9 out of 10 rounds cycled, with one stoppage during feeding and no lock-open on the last round. Accuracy wasn't great. Averaged 1821fps with a large ES.
When loaded longer (about .15" into the case neck) over the same charge, groups shrank to 1.15 and 1.3", but with the slightly reduced pressure I think only one round cycled the action. Average velocity was 1801fps, with an ES of 95fps.
I also tried 20 rounds with 20gr of Unique (having worked up to that level with 150gr FMJBT with excellent accuracy), with 10 each loaded long and short as outlined above. Velocity was 2242fps, ES 25fps. Accuracy did not change between the two seating depths, staying around 1.7" for all four groups with 5 shots each at 50 yards. FYI, even at this charge the case necks were still a little sooty and primers were slightly rounder than starting-level published loads that I normally run. However, I haven't had much motivation to push any further with this powder.
At least from the prone position, I think 37 or 38gr should reliably cycle it. I'd expect about 2100fps. I'd probably run 39-40gr for increased reliability if I was planning on any offhand shooting with this load.
The wife will definitely love this setup. The one time she shot the rifle she did quite well for her first time shooting a rifle for any sort of precision (~3moa with this rifle and optic, prone) since her only other long gun experience was one time out with a Hi Point .45 Carbine. She enjoyed this a lot, but the recoil wore her out after a few groups (as I expected). But, since she got off to a good start and expressed an interest in working to improve, I have been working on reduced loads with what I have available, with a secondary goal of finding one that will also cycle the action. These are the first jacketed bullets that have shot accurately over significantly-reduced loads that still cycle (say, at least 40% reduction in recoil over standard loads). Unique has generally done well for accuracy, low recoil, and especially a mild report, but obviously doesn't cycle.
As a side note, I tried out some 135gr FP cast bullets from Badman over Unique powder (8 and 9gr) with pretty good results. 10 Rounds into 2" at 50 yards and about 1240fps, with 9gr of Unique under Dacron filler.