300 wsm load development and advice requested

Freediver111

Sergeant of the Hide
Full Member
Minuteman
Feb 28, 2018
320
110
Oregon
I had a Tikka t3x in .338 win rebarrelled by a smith with a benchmark 2b and chambered it to 300 wsm.
I shot a box of Hornady precision 200 gr ELDX through it and measured 0.8” groups moving at an average of 2750 FPS.
Today I had a chance to test my first round of handloads. I have 200 gr eldx and 212’s. Started with the 200’s using 65, 65.5, 66, and 66.5 grain loads using new Norma brass, CCI 250 LRM primers, and H4831sc.
I loaded 3 rounds of each and shot them all through a magneto speed Sporter.
Here are the results:
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I was hoping for a little tighter groups but that could be me. It was cold and windy today, maybe not exactly on my game. Looks like 65.5-66 is the sweet spot. I was shooting for a velocity of 2850 FPS or thereabouts. I’m leaning to load some rounds in the 65.5 range and testing for seating depth next. All of these were loaded 0.02” off the lands. Thoughts? The 66 grain loads had a reasonable ES/SD, with a slightly larger grouping. That being said, it’s in the velocity range I’m looking for. Maybe try that load and testing for seating depth!?