Factory Crimp Die Question

rayzorloo

rayzorloo

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Hey all, I was using a factory crimp die for 9mm, I noticed that certain cases seemed like they were getting shaved a bit. I saw brass flaking off on to the press, and noticed that the top portion of the brass got shinier where I would guess the 'scraping' happened? Any thoughts? Is this normal-ish?

Thanks in advance
 
The vast majority of reloaders do not trim their cases to the same length. This means the longer cases will be crimped more that increases the chance of the case bulging below the crimp with brass shaving.

Also the crimp section of the die can be rough and shave brass off the mouth of the case. The longer cases will be expanded more and rub this rough area more and leave brass shavings.

And if you wet tumble your pistol cases it can peen the case mouths, this means more brass shaving during crimping.

khT8EaK.jpg


I cured the problem by using a Lee type "M" expander and seating and crimping in separate operations.

NOTE, the Lee factory crimp die with the carbide ring in its base is simply a cheat for reloaders who do not trim their cases to the same length. If the case bulges below the crimp the carbide ring will size the bulging crimp back down. The downside to this type die is oversized cast bullets "may" be sized down in diameter.

Below the type "M" expander dies do not over expand the case mouth and the bullets are started straight into the case. And as you can see on the case on the far right the case mouth is expanded more and the crimp die will scrape off more brass shaving.

vwgkeH3.jpg
 
I have a Factory Crimp Die for 9mm but don't use it. My Lee bullet seating die seats and taper crimps sufficiently in the same step. Love the Factory Crimp Die for revolver cartridges though.
 
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