Trimming 9mm Brass

[roknHS]

I started with 1000, clean, once fired brass from the local range. I sized, deprimed, expanded the neck and started the trimming process with a Forster hand trimmer. I find the neck on most cases still extremely tight on the trimmer pilot. I mean tight-tight, to the point I have to put a huge effort into turning the cutter shaft and sometimes the brass case spins in the collet. I went back to the expander die and checked to make sure I had the case mouth opened enough to start a bullet with my fingers.......it is......so, I don't want to expand the mouth of the case further. After a hundred trims, my fingers get sore enough I take a break. I decided to look at power trimmers for this 9mm project. Because I already had the Forester gear, I figured I'd use the Forster power trimmer and my drill press. I have read the reviews on this trimmer and they all seemed positive. That hasn't been the experience I've had. The trimmer is hard to set up on the drill press, it is difficult if not impossible to set the exact trim length and the pilot still gets stuck in the case mouth and pulls out of the cutter head even though the allen head screw holding it in is as tight as I can get it. And, it is no faster (maybe slower) than using the hand trimmer. It was a total waste of $70 bucks.

I'd like to know if there is something I'm missing here. I also reload for 40 S&W and have no trimmer problems. I'm sure its the tapered 9mm case characteristics that have me dreading the second round of reloading for the 9mm. I've now finished 1400 pieces that are ready for powder and bullets. I guess I need another power trimmer. I hate to spend hundreds of dollars just to handle the 9mm's but, I'd rather take a beating than tackle another round with the hand trimmer. I need suggestions from some with more experience on the 9mm. From my experience, the 9mm's stretch a lot after resizing.........much more than the 40's. I've done a similiar amount of 40 S&W and many don't need any trim. All the 9's require trimming.

Is trimming 9mm always difficult? Is there some technique I'm missing or do I just need an expensive trimmer?

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[Throckmorton]

some thoughts,and imho'.s
trimming that brass is prolly not necessary,but can't hurt.Shoot both kinds,trimmed and not,and see if you think it's worth it.
you flare after trimming and cleaning the case mouth,not before.
What is the diameter of the pilot you are using ?
what are the size ranges of the sized,un-trimmed brass ?

 

[BillM]

There is a bit of variation in 9mm wall thickness, and that combined with it being a tapered
case might be grabbing your pilot. Try taking the pilot off of the cutter ram and dropping it in
the cases--it should go easily. If it doesn't, chuck it in the drill press and polish it down until it does.

That said----I have never in over 100,000 rds each trimmed 9mm, 40 S&W or 45 ACP. Never
had a problem. What are you shooting that you feel trimming cases is necessary? FWIW,
straight walled pistol cases tend to get shorter when fired. Not sure about the tapered case
on 9mm, never measured any.

 

[rocky3]

why would you worry about trimming 9mm? Use your calipers on store bought ammo and reload accordingly.
Read your book carefully and I'm sure you will find trimming of brass applies to rifles only.

 

[roknHS]

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?

 

[evltwn]

Well, you got me curious, so I checked my Lyman's 49th edition, my Lyman Cast bullet handbook and one of those "one book/one caliber books for 9mm. Both Lyman's books indicate a trim to length of .751. At various places in the third book it mentions .744, .750 and .751, depending on bullet manufacturers. My 9mm trimmer pilot mikes at .349. Could that be why yours requires so much effort?

I randomly miked 10 previously fired cases, and 5 were .742, with the rest ranging from .743 to .746. Personally, I shoot and reload perhaps 4000 9mm a year, and have never trimmed one yet.

 

[Throckmorton]

since most 9mm bullets are .356,that .358 pilot which would work great in .38 special cases just might be a bit too large and causing the problem.
you are correct,having the cases the same length could aid in accuracy and feeding,etc,but very very few shooters trim pistol brass.Not saying you're wrong,we may be wrong. but all my ammo feeds and goes bang.
Mike your sized cases to get an average of the ID after sizing,and polish the mandrel to fit.But don't flare them before trimming.,

 

[AMProducts]

In all my years of reloading, I have never trimmed a single piece of straight-sided pistol brass, and I have yet to have an issue. YMMV.

 

[cookie]

I don't think anybody trims pistol cases.

 

[Swampr]

I trim my 44 mag brass, but not my 9mm or 40s&w.

 

[ron]

I have reloaded many thousands 9 mm and 10 s of thousands of 45 acp. I started reloading
in 1978 and now load on a Dillon. I have NEVER trimmed a pistol case!! No issues
and my reloads are more accurate than factory ammo that I have tested.

 

[Certaindeaf]

Size and then bell it and then trim it and wonder why it doesn't fit in your gizmo?
Also, you say "once fired brass from the local range.."
Did you watch all of those rounds come out of a new box (after inspection) and then pick them all up yourself or did.. nevermind. I don't think it matters really but for my high end rounds, I do like them to be new or a few (but equal) times fired.
Oh, and I think you gathered, unless you're perhaps a Olympic gold medalist, trimming straight walled cases is really never done. I think they actually shorten but having them the same length certainly wouldn't hurt..

 

[roknHS]

OK, the verdict is in..............nobody trims 9mm or any other straight wall cases for that matter. I'll stand in the corner with the dunce hat on. But, I'm smiling cause now I know I don't have to go through that torture again.
Thanks for setting me straight.

 

[Mikej]

OK, the verdict is in..............nobody trims 9mm or any other straight wall cases for that matter. I'll stand in the corner with the dunce hat on. But, I'm smiling cause now I know I don't have to go through that torture again.
Thanks for setting me straight.

Indeed...I went through the same thing for a bit when I started, but not 1400 cases! You mention crimping, there's really no reason to do much crimping on cases that headspace on the case mouth. Only crimp enough to get rid of the bell in the case. And yes, you'll feel a difference as you crimp, just keep it on the light crimp side and don't wrinkle cases. You may want to do some before and after measurements of COAL in the remaining rounds in a mag if you were shooting some ULTRA hot loads, there's a slight chance bullets may back out a bit from recoil.

You will absolutely want to trim revolver rounds that require a roll crimp. Two reasons are given, one is because of a bullet backing out of the case from recoil and binding the cylinder so it won't turn, in magnums. The other is to get an identical roll crimp on all cases. If case aren't trimmed to within .002 some will have a very light crimp or some will fold cases and won't load in the cylinder. I know this from personal experience!

Mike

 

[Throckmorton]

hmm. all my cowboy rounds have a crimp groove for a roll crimp,and I never trim them,no one I shoot with does either. Not that we are making of shooting MOA ammo,but it all goes bang and all hits steel.
the other Mike.

 

[Mikej]

hmm. all my cowboy rounds have a crimp groove for a roll crimp,and I never trim them,no one I shoot with does either. Not that we are making of shooting MOA ammo,but it all goes bang and all hits steel.
the other Mike.

I'm only into this reloading game 2.5 years but I learned early on with revolver/roll crimp ammo that mixed head stamp used brass can easily vary six or seven thousandths in length. I want that ram to feel the same every time, for the most part, when I pull the handle down to the bottom.

Plus, I figured if the poor guy twisted that crank, on a pilot that was .002 larger than the cases he was trimming, for 1400 cases, that he deserved a little heads up on the roll crimp rounds! His story made MY fingers hurt.

 

[Throckmorton]

if u set the roll crimp in the middle of the crimp ring,then it's only .035 variance,I can easily live with that,and have for 20 years. I used to be real 'attentive''..read anal...about my reloading,but get lazier by the year, lol. not unsafe,just not as 'attentive.

 

[Mikej]

if u set the roll crimp in the middle of the crimp ring,then it's only .035 variance,I can easily live with that,and have for 20 years. I used to be real 'attentive''..read anal...about my reloading,but get lazier by the year, lol. not unsafe,just not as 'attentive.

It's not the width of the crimp ring on the bullet it's self or the oal of the completed round that causes headaches. It is the crimp being light,(which is acceptable), on a shell that measures 1.147, and a shell that is 1.151 causing the finished round to wrinkle. Or if the seater/crimp die is set to crimp the longer case there will be no crimp on the shorter case.

 

[Certaindeaf]

It's really amazing that a good pistol, 9mm or .45, will group to under 2" at 50 yards with essentially factory/"target" ammo. Same with revolvers.

 

[Nitro 54]

I ran into the same tight problem with the 35 pilot trimming 9mm. I just use the 33 with no problems. The last time I was on the phone with RCBS I asked them about trimming pistol rounds. They told me that to get a consistent crimp, that all rounds should be trimmed to within .001 either way of desired length. 9mm cases I have measured have varied by as much as 12 thousands. With all cases trimmed, I have had 0 feed and eject problems with my reloads.