300 PRC OCW Test and Questions

[BasicMagic]

I’m running 2 thou neck tension now and have the 3 thou bushing

I’m using an adhesive barrel temp strip and waiting between shots until temp returns to ~90’ range.

I’m using an A&D FX-120
w/Auto trickler v3 for powder.

Shots are round robin per OCWReloading website.

I have a APA break on the rifle tightened per mfg instructions and find the recoil to be very manageable.

Yeah id add some neck tension and check a lower powder charge range, keep in mind regular groups are going to be smaller than round robin.

 

[BStark78]

I thought I would post an update…

Before I try a new powder I wanted to test a few other suggestions. First that I would find a node around 75.5. Below are the groups of 75.4 (2760 ES 45/SD 16.9), 75.5 (2765, ES 20/SD 7.5), and 75.6 (2774 ES 18/SD 7.1). I also added a bit of neck tension, +1 thou to 3 thou. ES and SD dropped about 15% for two of the loads vs. the previous loads at 2 thou.

The sighters are clean/cold bore at 74.6 w/ an ES of 12 and SD of 5.1. The cluster of three are shots 2-4 (1 is the lowest).

I’m happy to see the ES/SD numbers come down a bit. I’m hoping with a different primer I can trim that another 15-20%. The vertical shift is still rather extreme for a very small power change.

I’ll most likely stick with 74.6-74.9 for now. It’s exhibited the least vertical shift of all series of shots across 3 sessions.

I’m working on picking up some new powder and have 2 new primers to try. I also picked up some Lapua brass when it came available recently.

As a note, at 75.7 w/ADG brass I see light ejector marks (Hodgdon published max).

 

[seymour fish]

I don't see a node. With that high capacity I would look at a wider charge range at 0.5 increments, which I think a ladder test may show more clearly than ocw.

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