I have a problem that I don't know how to solve. This is from several barrels & rifles all cut with the same reamer. This is what fired brass looks like:

Doesn't matter if it's virgin brass, turned or un turned. All have soot on the shoulders and I think that is causing some blow by that is negatively impacting down range performance.
As you look at the pics above you are going to thing that the case mouths are curled in. Maybe they are. That was an initial problem but I have been trimming them .020 short. A bullet does fit into a fired case mouth. Maybe that is the answer -- get a neck reamer and make sure the neck is a true cylinder rather than a cone.
I tried just about everything i can think of to stabalize ES and even when it is reasonable like in the 8 range the targets are all vertical. I've posted some targets below. I have dozens more that should all be 200-19X or 200-18x. I don't have a wind problem. I have a vertical problem.
If I were ordering this reamer today, I'd make many different choices like at the .200 line, the neck diameter and freebore as well but here it is:

And, lastly, here is what you get on paper:


Wide open to any suggestions you guys have.
Thank you,
Hank

Doesn't matter if it's virgin brass, turned or un turned. All have soot on the shoulders and I think that is causing some blow by that is negatively impacting down range performance.
As you look at the pics above you are going to thing that the case mouths are curled in. Maybe they are. That was an initial problem but I have been trimming them .020 short. A bullet does fit into a fired case mouth. Maybe that is the answer -- get a neck reamer and make sure the neck is a true cylinder rather than a cone.
I tried just about everything i can think of to stabalize ES and even when it is reasonable like in the 8 range the targets are all vertical. I've posted some targets below. I have dozens more that should all be 200-19X or 200-18x. I don't have a wind problem. I have a vertical problem.
If I were ordering this reamer today, I'd make many different choices like at the .200 line, the neck diameter and freebore as well but here it is:

And, lastly, here is what you get on paper:


Wide open to any suggestions you guys have.
Thank you,
Hank