This data was taken with gage #2, as discussed on another thread, and no adjustments were made to the calibration even though the validation load was 5000 psi high. In other words, I believe the pressures shown here may be about 5000 psi higher than the true pressures.
Here's one round left over from last time with IMR 4350 pushing a 180 gr. loverin, as discussed on a previous thread.
** missing pressure chart, darn it **
Here's a new improved 180 gr. loverin pushed by Ramshot Big Game. Big Game is faster burning than 4350 and I bought a pound hoping it would solve the secondary spike problem. Obviously, it didn't. The particulars are 53 gr. Big Game, Fed 210, HTWW, Rooster HVR, 2.975" COL, and the front band engraved the rifling. Five shots spanned 6.4" at 100 yards. Velocity was 2573 fps.
By the way, there is a big discrepancy between what Quickload predicted and what Western Powder Co. data predicted for this powder. Now that we have some hard data, Quickload is vindicated.
** missing image, darn it"
Here's a 180 gr. bore rider pushed by Ramshot Big Game. The particulars are 54.1 gr. Big Game, Fed 210, HTWW, Rooster HVR, 3.133" COL, and the 0.3007" nose did not engrave the bore when seated just deep enough to cover the lube groove. A loverin makes more sense for this long-throated rifle, but I had to try a bore rider just to say I tried it. Velocity averaged 2769 fps.
** missing image, darn it **
How about those secondary spikes? Yes, they are real, and yes, they suck. They go off the scale, so we don't know exactly where they top out, but it looks to be 120 ksi or so, enough to put the gun in harm's way. Since Big Game didn't get rid of the spikes, I'll try an even faster powder next time, maybe Varget. I suspect it would also help to load to SAMMI max pressures, because these powders need pressure to burn correctly. Today I deliberately loaded below max because of the discrepancy between Quickload and Western Powder Co.
The secondary spike needs to be fixed before the poor accuracy can be addressed, since the spike may be part of the accuracy problem.