cowboy94
cowboy94
20 posts
Joined December 2011

triming cases

I have measured the cases on a 9mm and its still below the max length. just wonder if I should trim them or let them go til the reach the max length. I have trimmed a few but have not shot them yet.
dillon
Administrator
dillon
2,820 posts
Joined July 2007

RE: triming cases

No reason to trim them at all. Unlikely they will ever stretch enough to require trimming.
bluerocket
bluerocket
3 posts
Joined January 2012

RE: triming cases

Cowboy94, I've read that before you trim cases you should shoot and reload the new one's at least 5 or 6 times.  This process gives the cases a chance to anneal due to the heat from the powder ignition.  Then I would trim the cases to the recommended trim length.  Don't forget to chamfer and deburr the inside of the cases.

The only cases I trim are my 38 Specials that I shoot in my S&W Model 52-2 wad cutter target handgun.  This handgun is very particular about case length, if they're too long then the slide doesn't go into battery.  Unless your 9MM cases are so widely varied in case length I wouldn't trim them.  But you really need to measure them to be sure they aren't a little too long.  Hope this helps, regards Bluerocket

flesnhoj
flesnhoj
6 posts
Joined December 2012

RE: triming cases

I have got about 500 rounds of 9mm that is well below max, .735-.742. These have been fired once maybe twice but I was concerned about the mild crimp I am using. the difference of .007 is not great but is it large enough to give me crimping issues?
dillon
Administrator
dillon
2,820 posts
Joined July 2007

RE: triming cases

Using a taper crimp, this variation is not extreme enough to cause a problem.