Trimming 9mm Brass

[ma96782]

For "just shooting ammo"......

I wouldn't bother to trim straight walled brass.

I do it only for bottle necked cases.

And, about that pilot....just chuck it into a drill and grind it down a bit to where you like it. Then, there is also other methods/tools to use that could greatly speed up your trimming tasks. Of course, they are expensive when compared to your hand trimmer.

Aloha, Mark

 

[v0lcom13sn0w]

yep. as said from above, i too have never trimmed any 9 or 40 brass. never had a problem.

 

[whiskeybill]

Well, sounds like you all don't worry much about trimming 9mm. Before I started this project I did some background research to make sure I knew what I was doing. I read that these pistol cartridges headspace on the case length. Therefore, it seemed important to have uniform case length to get the right headspacing. Also, you get a consistant crimp on the bullet during the seating process.

I'm trimming to .744 as per my Speer manual, the pilot I'm using is described as a 9mm with a Dia. of .358

I would love not to have to trim these cases...........maybe I was being too "anal" again?

9mm bullets are .355" and the pilot is .358". That would be a tight fit on a sized case, even when flared. If you feel you must trim, try doing it before sizing. Just a thought.

 

[roknHS]

Thanks for the input and ideas. I will definitely reduce the pilot size if I decide to trim 9mm again.
I did find that case length changes after resizing...........I think to get a consistant case length after trimming, the case should be resized first.
My step process would be:
Resize/deprime
Trim
Expand mouth
Prime
Charge
Seat and crimp bullet

Of course there is some inspection, cleaning, chamfering, etc. that goes on during the process without saying.

 

[RVTECH]

I like the others who have reloaded 1000s of 9mm without trimming still think you can skip the this step. Trimming 9mm brass seems like a real pain. If it was something I 'had' to do I probably would not own (much less reload for) a 9mm, or any auto for that matter.

 

[noylj]

Why would any one trim 9x19 cases? They don't grow. They aren't bottleneck cases.
Worst of all, the round head spaces on the case mouth and trimming increases the head space. Excess head space is detrimental to accuracy. Trimming will, in fact, leave the case either hanging on the extractor, crooked, or far enough into the case to effect primer impact and primer set-off.
With all time wasted doing bench rest load fiddling for a handgun round, why isn't the whole issue of head space considered?
Have any you EVER read any manual that recommends trimming straight-wall cases, which do not grow like bottleneck cases and in fact shrink with continued loading?
Consistent crimps are ONLY an issue with roll crimps. Taper crimps are simply to remove any case mouth flare, will ALL bullet tension controlled by case/bullet fit.
Trim all you want, but you REALLY should be trying out some of the longest cases (0.749-0.754") and compare accuracy with the shorter cases and those you trimmed. A little experimentation will tell you more than calling a company that makes money selling trimming equipment.