I have a Ruger RPR, 6.5 CM with a Proof Research 24" Carbon Wrapped barrel.
I've been slogging away to find a bullet powder combination the barrel likes. While just about everything I throw through the rifle is Sub MOA, I was hoping for a bit better.
Two weeks ago I thought I found the load. Berger 140 VLDT over a Lapua case and 41.2 Gr of H4350. The Target analysis software showed it to be a .1 MOA spread at 100 yards, at an indoor range. The load was a little "hot" but there were no signs of excess pressure on the primers and the velocity was only just over the 2700 FPS threshold, and I've been working up to that level over several sessions.
I was shooting three round test groups, at 2726 FPS measured at the muzzle, Each powder load is + or - 1 pellet off the target load, with a slight crimp on the round. Each case is run through a neck sizing done with the body only slightly touched.
I was reloading with a Hornady Ammo Plant progressive, but found the seating consistency was not exact enough. So I picked up a Hornady Iron Press and the seating of the bullets, .020 off the lands, is + -r - 0.0005".
In any event the next time went out I had cleaned the barrel, and ran three 5 shot groups one .1 Gr above and below the target load and one at the target load.
The spread was about .5" to .7"
I'm a bit perplexed in that I can't at least get close to the original group.
Thanks in advance,
Bryan
I've been slogging away to find a bullet powder combination the barrel likes. While just about everything I throw through the rifle is Sub MOA, I was hoping for a bit better.
Two weeks ago I thought I found the load. Berger 140 VLDT over a Lapua case and 41.2 Gr of H4350. The Target analysis software showed it to be a .1 MOA spread at 100 yards, at an indoor range. The load was a little "hot" but there were no signs of excess pressure on the primers and the velocity was only just over the 2700 FPS threshold, and I've been working up to that level over several sessions.
I was shooting three round test groups, at 2726 FPS measured at the muzzle, Each powder load is + or - 1 pellet off the target load, with a slight crimp on the round. Each case is run through a neck sizing done with the body only slightly touched.
I was reloading with a Hornady Ammo Plant progressive, but found the seating consistency was not exact enough. So I picked up a Hornady Iron Press and the seating of the bullets, .020 off the lands, is + -r - 0.0005".
In any event the next time went out I had cleaned the barrel, and ran three 5 shot groups one .1 Gr above and below the target load and one at the target load.
The spread was about .5" to .7"
I'm a bit perplexed in that I can't at least get close to the original group.
Thanks in advance,
Bryan