Handloader need some help.

First off this is the probably the most difficult caliber I have found to load for. If I put a regular taper crimp, it jams and then pushes the bullet back into the shell. I chambered a round 5 times starting off at a COL:1.135" and each time it pushed the bullet back a hundreth. So then put a very heavy crimp on it. And buckled the cases. Would jam in my chamber.

I find that the only way to get this to work is to crimp to right on the edge of buckling the case. And still, It will push the bullet back a little while chambering.

What this round needs is a carbide factory crimp die from lee. Maybe my barrel needs some work. Maybe this Speer 125gr gold dot (made for the .357Sig) is not a good choice. Maybe this once fired speer brass from midway doesn' t have good neck tension. But any way it goes I find it to be a tough one. Any suggestions? One thing I found out, is its better to crimp on a separate operation on a single stage. Instead of crimping and seating the same time on a lee 1000 progressive.