Brass Problem

[IceSniper]

Today i went to reload 15 rounds that i fired last night and after resizing i noticed my case trimmer wouldn't fit in the necks of 12 of them /ubbthreads/images/graemlins/confused.gif , I tryed resizing them again but it made no diffrence. Then thinking something had gone wrong with my die i cleaned it out and tryed again with no success. Finally i tryed depriming/resizing some winchester brass and my cutter fit fine. So if it's not the die or the cutter it must be the cases. But then my expander ball should pull the neck open on the up stroke regardless, yes?
I'm confused.
What could be causing this and how do i fix it? I can't give measurements because i still haven't brought a caliper /ubbthreads/images/graemlins/blush.gif .

As a side note the 3x 5-shot groups i shot last night averaged 6.6mm for 3 shots and 16mm for 5 shots. Not bad at all for a factory standard M10FP /ubbthreads/images/graemlins/grin.gif .

 

[Fiftydriver]

First off, what is the chambering of the rifle you are shooting? What brand of brass are you using and what is the diameter of the pilot on your case trimmer?

Kirby Allen(50)

 

[green 788]

Yeah! /ubbthreads/images/graemlins/laugh.gif

 

[IceSniper]

oops /ubbthreads/images/graemlins/blush.gif .

I'm shooting a .308win with Norma brass. The pilot on my trimmer is around 7.5mm but i can't say anymore accuratly because i don't have a caliper (I've really gotta order that!). It's one from LEE if that helps and it usally slides in the necks with a TINY amount of pressure, but on these cases it slides over the first section fine but once it goes in passed the machined out bit where the caliber stamping is it stops and gets stuck.

 

[green 788]

The Lee case trimmer works. I like that system better than any other I've tried.

I just chuck the cutter/case gauge in my drill press, and slip the lock stud on the case head and with the press on low speed, I run the case up onto the spinning cutter. Works great. I can trim at least five cases in the time it take other guys to trim one. /ubbthreads/images/graemlins/laugh.gif

You are limited to a fixed trim length with the Lee system, but you can actually shorten the gauge pin a bit (with a file or stone) for a shorter trim length, and I've actually pulled that pin out and put a grain or two of sand inside the hole, then put the pin back in for a longer gauge...

worked out great. /ubbthreads/images/graemlins/smile.gif

But to answer your question, you need to trim the cases BEFORE you size them. With some grades of brass, you might be able to get the cutter length gauge into the sized case neck, but obviously the Norma isn't giving up enough neck tension to allow this.

In any event, you don't want to trim the cases after you've sized them. Pushing the mandrel (the length gauge) into the case mouth with some degree of force will just loosen your neck tension--and you don't want to do that.

Measure the cases which you have already sized. If they are not longer than 2.015" you'll be fine to go on and fire them, I feel sure. You'll of course have to get a micrometer... these can be had for around 25 to 30 dollars, and you need one BADLY! /ubbthreads/images/graemlins/laugh.gif

Dan