Freebore for Hornady 190gr A-Tip, 7 PRC?
- Thread starter SteveOak
- Start date
I’d mock it up but without looking at my notes at home I’d say .180-.210.
Ditto for gathering the components you're going to use and sending a mockup to the reamer supplier.
This is what 0.250" looks like with the 190 ATip in a 7/300PRC case.
This is just touching the lands which is not a setting I'd ever use.
In addition to components, the freebore selected will depend on your reloading strategy. Jump or jam, back of bearing surface ahead of or behind neck/shoulder junction.
Neck turn or no neck turn is another big decision. If ELR is going to be your game, I suggest you get good at it. If you compare the SAAMI 7PRC chamber drawing and the neck thickness of boutique brass, you'll run out of neck clearance pretty quickly. 0.003" is about the minimum for consistent velocities. 0.004" will get you a few firings before velocity fliers appear if the bullet bearing surface extends into the shoulder. Neck thicknesses below maybe 0.014" will keep neck tension down and make seating the bullets without marking them easier. I like the K+M tool. Easy setup and adjustment. I use the boring mandrel. SS for anything that cuts. Carbide lasts longer but the surface finish isn't as nice. I've gone back and forth on cutters. The picture above looks like a radiused cutter. The other option is an angle a couple degrees steeper than the shoulder. I think the angled cutter is harder to screw up.
This is what 0.250" looks like with the 190 ATip in a 7/300PRC case.
This is just touching the lands which is not a setting I'd ever use.
In addition to components, the freebore selected will depend on your reloading strategy. Jump or jam, back of bearing surface ahead of or behind neck/shoulder junction.
Neck turn or no neck turn is another big decision. If ELR is going to be your game, I suggest you get good at it. If you compare the SAAMI 7PRC chamber drawing and the neck thickness of boutique brass, you'll run out of neck clearance pretty quickly. 0.003" is about the minimum for consistent velocities. 0.004" will get you a few firings before velocity fliers appear if the bullet bearing surface extends into the shoulder. Neck thicknesses below maybe 0.014" will keep neck tension down and make seating the bullets without marking them easier. I like the K+M tool. Easy setup and adjustment. I use the boring mandrel. SS for anything that cuts. Carbide lasts longer but the surface finish isn't as nice. I've gone back and forth on cutters. The picture above looks like a radiused cutter. The other option is an angle a couple degrees steeper than the shoulder. I think the angled cutter is harder to screw up.
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