I was surprised to see the dimensions that you use to load your ammo to, especially the case mouth dimension. I know the .380 spec is within the acceptable tolerance but is the maximum diameter acceptable. The reloading manual I read before starting reloading told how to set the taper crimp on the cartridge this way: First they recommend sorting brass since case wall thickness varies, and I do that. Next is to measure the case wall thickness, and the bullet's diameter. So, if you are using a .356 bullet and the case wall thickness is .010, the outside diameter of the crimp should be .375. That is the bullet diameter added to two times the wall thickness since you are measuring two walls and crimping the round .001 results in the total of .375. Try loading a dummy round without primer or powder and then pull the bullet out of the case to see how much indentation is shown on the bullet to ensure you are not over crimping. You should be able to see only very slight evidence of bullet compression. I do this for every set of ammo I load, especially when different case manufactures are being used. The crimp does nothing to hold the bullet, case tension does that and is determined by case resizing. Over belling the case mouth too much will cause problems seating or crimping the bullet or too deep will lose the tension. I have used this method for all my reloads and they work in every gun I have. The only problem I ever had was with some coated RN bullets that were .358 diameter and the quality sucked. The bullets were very inconsistent in size and weight, had slag on the bases of some, and the ogive was so fat that I had to seat them deeper than recommended. I loaded these to shoot in Beretta pistols since the bore size in about all of them is .3575 and the plated bullets, cast bullets, or lead bullets should be at least .001 larger than bore size.
I hope this will help with the chambering problems with your reloads.
DanOh
I hope this will help with the chambering problems with your reloads.
DanOh