Need some help here gents, running out of options. Can't seem to get this rig to shoot anything.
Rifle is a 6x47L, 26" 8 twist M24 Spencer barrel, Curtis Custom Axiom action in an MPA chassis. Just under 17 pounds in all.
Brass prep. Turning the necks on Lapua brass to about .013 while at the. 264 diameter, (same method and K&M equipment that I use with all other cartridges). First step the necks down to 6BR in a Forster CoAx press, then on to a Forster 6x47L full length die, finish by expanding up with a mandrel to .0025 neck tension, champher mouth, debur flash hole...done. Brass looks great, square, no bell ends. After initial firing, cases are sized with a Whidden bushing die (and expanded with a mandrel), shoulders bumped right at .002. Bullets are seated with a Whidden seater and checked for runout.
Ran about 10 rounds down the barrel to break in, inspecting an cleaning as necessary. Pulled the copper after the first and 10th rounds, no copper showed after that. Cleans up easy. Shot these 10 in .03 grain increments @ .005 off to see if I could find a flat spot while I was breaking it in and one showed at 3020 (110 SMK's). I usually shoot these in more or less an OCW style, you can usually see the POI shift around the bull and get a real good idea of what's going on. Of course operator error can happen when unexplained things show on target. Noticed right away during this test that there were severe flyers. Every 2 or 3 shots it would spit one 1.25" off somewhere, then return halfway close to where it should be.
First firing of cases all seemed to have a little heavy bolt lift and the start of a cratered primer. I assumed that pressure would be a little higher initially when forming these to the 6x47 chamber from 6.5x47 brass.
Seating depth test first for 110 SMK's. Seated 3 each at .005, .025, .045 off with 39.3 grains of H4350, CCI 400 primers. No preference was shown for any seating depth, there was at least one flyer around 1.25" in each group. ES was shockingly good at 14, 6, and 6...small sample size I know. Velocity was 3045, 3026, and 3011 respectively, decreasing as expected as depth increased. What I didn't expect was a heavy bolt lift and ejector marks on everything seated .045 off. Higher velocities did not show any pressure really.
Since none of the seating depths showed favor, I chose .005 off and loaded up 5 at the flat spot I found before to see what they would do. Velocity was as expected, but the group was about 1.75". I am not sure I have had any rifle ever shoot a group that bad when loading for it.
At this point I started questioning my brass prep...didn't know what else it could be. So I took the 5 cases I just shot and loaded them again to see if perhaps that was the issue. This time it shot slightly better, maybe 1.25"
At this point I started checking everything. Rings, rail, action screws, make sure barrel is floated and cleaned it. Nothing helped. I did multiple tests like this with 110's and nothing was any better. I have also started the process with the 105 hybrids and so far it's doing the exact same thing although I am not done yet. I am going to try a few more things with 105's and I am going to swap out the scope today. If that doesn't work, I'm stumped.
Other things that don't add up. Brass is always tighter than expected coming out of the chamber after firing. Doesn't matter if it is once fired or virgin, just heavier bolt lift that one would expect or want even when there is no pressure signs. Primers are almost always somewhat cratered no matter the charge, even if no other pressure sign is apparent. The neck on shot cases are about .001 out of round as you rotate it in the calipers.
There is an accuracy guarantee of 3/8th for the rifle, but I want to make sure I cover all my bases before going that route. It seems to me that if a rifle is going to shoot well, it normally shoots everything reasonably well. This doesn't shoot anything worth a crap so far. Normally you would see some sort of direction on paper of where to go, but this is giving me nothing and I don't want to continue blowing $$ and time out the muzzle for no results.
What am I missing here? Any help would be appreciated.
Rifle is a 6x47L, 26" 8 twist M24 Spencer barrel, Curtis Custom Axiom action in an MPA chassis. Just under 17 pounds in all.
Brass prep. Turning the necks on Lapua brass to about .013 while at the. 264 diameter, (same method and K&M equipment that I use with all other cartridges). First step the necks down to 6BR in a Forster CoAx press, then on to a Forster 6x47L full length die, finish by expanding up with a mandrel to .0025 neck tension, champher mouth, debur flash hole...done. Brass looks great, square, no bell ends. After initial firing, cases are sized with a Whidden bushing die (and expanded with a mandrel), shoulders bumped right at .002. Bullets are seated with a Whidden seater and checked for runout.
Ran about 10 rounds down the barrel to break in, inspecting an cleaning as necessary. Pulled the copper after the first and 10th rounds, no copper showed after that. Cleans up easy. Shot these 10 in .03 grain increments @ .005 off to see if I could find a flat spot while I was breaking it in and one showed at 3020 (110 SMK's). I usually shoot these in more or less an OCW style, you can usually see the POI shift around the bull and get a real good idea of what's going on. Of course operator error can happen when unexplained things show on target. Noticed right away during this test that there were severe flyers. Every 2 or 3 shots it would spit one 1.25" off somewhere, then return halfway close to where it should be.
First firing of cases all seemed to have a little heavy bolt lift and the start of a cratered primer. I assumed that pressure would be a little higher initially when forming these to the 6x47 chamber from 6.5x47 brass.
Seating depth test first for 110 SMK's. Seated 3 each at .005, .025, .045 off with 39.3 grains of H4350, CCI 400 primers. No preference was shown for any seating depth, there was at least one flyer around 1.25" in each group. ES was shockingly good at 14, 6, and 6...small sample size I know. Velocity was 3045, 3026, and 3011 respectively, decreasing as expected as depth increased. What I didn't expect was a heavy bolt lift and ejector marks on everything seated .045 off. Higher velocities did not show any pressure really.
Since none of the seating depths showed favor, I chose .005 off and loaded up 5 at the flat spot I found before to see what they would do. Velocity was as expected, but the group was about 1.75". I am not sure I have had any rifle ever shoot a group that bad when loading for it.
At this point I started questioning my brass prep...didn't know what else it could be. So I took the 5 cases I just shot and loaded them again to see if perhaps that was the issue. This time it shot slightly better, maybe 1.25"
At this point I started checking everything. Rings, rail, action screws, make sure barrel is floated and cleaned it. Nothing helped. I did multiple tests like this with 110's and nothing was any better. I have also started the process with the 105 hybrids and so far it's doing the exact same thing although I am not done yet. I am going to try a few more things with 105's and I am going to swap out the scope today. If that doesn't work, I'm stumped.
Other things that don't add up. Brass is always tighter than expected coming out of the chamber after firing. Doesn't matter if it is once fired or virgin, just heavier bolt lift that one would expect or want even when there is no pressure signs. Primers are almost always somewhat cratered no matter the charge, even if no other pressure sign is apparent. The neck on shot cases are about .001 out of round as you rotate it in the calipers.
There is an accuracy guarantee of 3/8th for the rifle, but I want to make sure I cover all my bases before going that route. It seems to me that if a rifle is going to shoot well, it normally shoots everything reasonably well. This doesn't shoot anything worth a crap so far. Normally you would see some sort of direction on paper of where to go, but this is giving me nothing and I don't want to continue blowing $$ and time out the muzzle for no results.
What am I missing here? Any help would be appreciated.
