Re: RL33 Temperature Regression Thread
Did some more testing last Friday and here are the results
6-284, 105 Hybrid targets over 60 gr RL33, 26" 5C Broughton (low pressure load)
Cold rounds were cold soaked in my freezer @ 5*. Then I transported them in a small cooler with an ice pack from the freezer. Temp in the cooler remained about 20* for about an hour prior to shooting, Warm loads were loaded at room temp of 70* then placed on floor of vehichle by the floor heater. The floor area remained about 80-85 for about 1 hr prior to shooting.
5 shots of each were fired
Cold rounds, 20*.... 3302, 3302, 3282, 3293, 3295.. Avg, 3295
Warm rounds, 80*.. 3322, 3311, 3313, 3304, 3302.. Avg 3310
Avg fps/degree diff, 0.25 fps/degree
Fairly consistent with the first test of this load.
Also tried the 6.5 WSM, 160 Matrix over 65.5 gr of RL33, 27" 5C Broughton barrel. Results were squirrely. The rifle was show pressure issues similar to previous when originally working up loads with my nitrded barrels.
Cold rounds, 20*....3084, 3132, 3119... Avg, 3112
Warm rounds, 80*..3134, 3097, 3099, 3113...Avg, 3111
Essentially no apparent affect. Like I said, the rifle was showing signs of weird pressure. This load was about 2 gr less than the original max working load I dtermined from ladder pressure testing. Cold rounds produced a medium heavy bolt lift and ejector marks. Warm rounds did not. I then proceeded to shoot some accuracy test rounds from 66 to 64.5. After firing 6 total rounds to get zeroed in with various charges of 65.5, 66, 65 and 6.45. I blew a primer with the 64.5 load, got the case stuck in the chamber and called it a day. All rounds showed pressure signs of heavy bolt lift and ejector marks. Ambient temp was 45.
Bottom line, I would not put a lot of faith in temp regression test with the 6.5 WSM rounds.
Results from the 6-284 are looking good. Still hope to do more testing and looking for anyone else who might have useful data to share.
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