I purchased the bulge buster specifically for the 40 S&W cases. I had been having some "light hammer strikes" in striker fired pistols. Thought maybe the bulge was causing it. Finally swapped to Federal primers and that fixed the light strike issue.
However, I still use the kit anyway on 40. Many didn't affect feeding, just didn't like the look of the slight bulges you often see on that brass. I feel like a uniform sized case will be more reliable in the long run. No doubt it does even up the rim on cases when ran through it also. Can't recall ever using it on 45 acp as I have never noticed any bulge on them. I just started using it on 10mm's just for uniformity. I have also used it on 380 acp and I found out you can use the 380 acp factory crimp die and the bulge buster on .223 brass. Sometimes you have a bulge on it near the base and it will knock that bulge off that the full length size die couldn't reach. They are dimensionally close enough to work in this instance.
The bulge buster kit will only work on straight walled rimless automatic pistol cases. It will not work on 9mm or other tapered pistol cartridges. Do not attempt to use it on the 9mm as it may jam in your die and will definitely deform your brass. I tried it once before it dawned on me it wouldn't work on tapered cases.
Rosewood
However, I still use the kit anyway on 40. Many didn't affect feeding, just didn't like the look of the slight bulges you often see on that brass. I feel like a uniform sized case will be more reliable in the long run. No doubt it does even up the rim on cases when ran through it also. Can't recall ever using it on 45 acp as I have never noticed any bulge on them. I just started using it on 10mm's just for uniformity. I have also used it on 380 acp and I found out you can use the 380 acp factory crimp die and the bulge buster on .223 brass. Sometimes you have a bulge on it near the base and it will knock that bulge off that the full length size die couldn't reach. They are dimensionally close enough to work in this instance.
The bulge buster kit will only work on straight walled rimless automatic pistol cases. It will not work on 9mm or other tapered pistol cartridges. Do not attempt to use it on the 9mm as it may jam in your die and will definitely deform your brass. I tried it once before it dawned on me it wouldn't work on tapered cases.
Rosewood