Following suggestions from Graybeard members I bought a Lee Factory Crimp die to crimp my 30-30 loads. My factory die already did the job okay, and I want to experiment with the Factory Crimp die. I was impressed with the results. I used it on a 100+ loads. I recently fired a bunch of them. I first loaded them into the Marlin magazine, and loaded the chamber from the magazine. The crimps held tight. I think the crimp from the Crimp Die is easier on the case then the roll crimp created by my standard reloading dies.
After trying the Factory Crimp Die on my 30-30 cases I pulled out a Lee Factory Crimp Die I bought new a few years back for the .270 Winchester. I crimped a run that used the same components I have been loading for years. I was satisfied with the results and will continue to use it on the appropriate bullets. I was a little more mindful this time around because of a round I dropped. The bullet popped out and powder was spilled on the ground.
My old reloading die has done a good job, a few years back I dropped one of my reloads on the ground when unloading my rifle. It bent the tip, but the bullet stayed in place.
“This is the third time these shells have been loaded”
Your cases maybe growing and need trimming. While I have a more expensive Forester case trimmer I find the Lee case trimmer setup cost effective and when powered by my cordless screwdriver/drill speedy. When I started using .270 reloads in my high school years in the past century I had them loaded for me. About the 3rd or 4th reload I started having chambering problems. About this time I expanded beyond the original Lee Loader, and purchased a Forester trimmer. I am sure that if the Lee Case Trimmer was on the market I would have started there. Proper case trimming resolved the problem.
In my cases the bullets were being seated to the cannelure, but the resulting cartridge was exceeding the appropriate case length. This also started showing up as high pressure.