Continuing with the powder comparisons ....
Here are the two bullets I'll be using today. I had forgotten that I had made the 120 in addition to the 130. Oh well, the joy of getting old.
Both bullets had already proven to be respectable performers with WC844. However, today's 130 was nose-sized less and seated deeper than the last time I shot the 130. Also the 130's alloy has changed, from WW to reclaimed shot, so it will not be a 100% apples-to-apples comparison.
Targets numbered in the order they were shot.
#1: H322 burned very well but accuracy was ho-hum.
#2 & #3: RL10 did well with the 120 grainer. Velocity variation was excellent, too.
#4: RL10 craps out when asked to push the heavier 130 grainer. Why? My guess is that these faster powders are "harsher" on the cast bullet as pressures and velocities go up.
#5: LT32, which did well yesterday with 120's, was ho-hum with the 130. Again my guess would be that pressure and "harshness" are to blame.
#6 & #7: same load & bullet as posted on May 21. But this time not as accurate, perhaps because of the different nose-sizing & seating.Conclusions:
-- While the 130 has proven itself just as accurate as the 120 (see the May 21 post), it's easier
to get accuracy with the 120. My theory is that the 120 operates at lower pressure and that makes life easier on the cast bullet. Ditto for why it was tough to get good accuracy with the 147.
-- With the 130 grain bullet, WC844 is my first choice, and LT32 my second choice.
-- With the 120 grain bullet I would include RL10 in addition to WC844 and LT32.
-- Seating the bullet deeper to improve reliable functioning may have hurt accuracy compared to the May 21 load. That was anticipated. However, it may be possible to compromise, and more sizing/seating comparisons are in order.
-- at the beginning of this barrel project I contemplated chambering it for 308 Winchester rather than 30 BR. The concern was that the BR would have to use fast powders to achieve my velocity goals, and fast powders tend to be "harsher" on cast bullets. I still suspect that this barrel might be more accurate with a 308 Winchester chamber and a medium speed powder like WW760. And that may happen next year if and when I get tired of playing with the BR. Things To Try Next Time And Down The Road:
-- settle on a powder, but in order to do that I need to settle on a bullet.
I'm leaning toward the 120.
-- comparisons with sizing/seating depth.
-- comparisons with wheelweight vs. reclaimed shot.
-- I'm nearly out of the CCI #41 primers that I've been using, so do a comparison with the Remington benchrest primers that I plan to phase in.