Lyman Universal Case Trimmer

[RiskyBusiness]

Hey guys, im in the process of prepping cases. Still have not bought components yet but will later this month.

I just finished sizing and depriming about 200 cases and the lengths are anywhere from 1.740-1.770. First, should i just trim them all to the length of the shortest case i have to have consistency in lengths or should i just aim at 1.750 and throw out the shorter cases. I understand after firing the shorter cases will grow but not by that much before they end up splitting. As long as i keep the OAL, should i be okay having a mix of brass 1.740-1.750?


Second, I used a case i already have measured at 1.750 in the case trimmer as a way to calibrate the trimmer. i locked the knobs and entered a case thats about 1.770 but after about one short trim the head of the cutter that enters the mouth of the case gets jammed in like your hs gf. It prevents me from trimming any further. I made sure it was resized and it enters the 223 case gauge i have so I dont know what gives.

[sethrus]

Check the oal spec for the brass. I wouldn't go much shorter.

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[Victor Cachat]

If you are going to crimp the case, it is more important to size them all.

If you are going to just use neck tension and none are out spec (long), I wouldn't worry about a small variation.

Full disclosure, I do try to size each batch to make them the same.
It's just a pain to chamfer them all after sizing.

[HBDano]

The trim to length for .223 is 1.750... so I personally wouldn't use brass that's shorter. If it's new brass, I would address it with whoever you got it from and get it replaced.

Not sure about your second question about the trimmer binding up as I don't use that trimmer.

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[rg1]

If your pilots for your Lyman Universal Trimmer were like mine they were too large and would hang in the necks. My solution was to put the pilot in a drill and using a smooth file with sandpaper wrapped around the file to reduce the diameter until they slide easily into a tight case mouth. Don't want it too small but after sanding mine down a couple thousandths they work perfectly. Need to have a polished surface after finished without scratches on the pilot.
I would measure all the sized cases and trim the long ones to 1.750". I would not trim them all to the shortest length. The ones that are 1.740" after sizing I would not trim and would load them at the length they are. Specs for .223 Rem cases are 1.760 maximum minus .030". I don't like cases shorter than 1.740" but at 1.740" they are perfectly good and safe to load.

[pacrat]

If you trim them all to match shortest case you will be GTG. As rg1 correctly stated, SAAMI case length spec is 1.730-1.760".

Is it the pilot that is binding on your trimmer? Cutter shaft is same as my Forrester. Very shallow chip clearance flutes. If you take a big bite while pushing hard. The chips bind in the shallow fluted face of the cutter. Made worse on mine, because I unscrewed the handle and use a cordless drill motor as a drive for it.

Try not pushing as hard and after each couple of turns, retract the cutter 1/4" or so while turning, to clear chips and go again. That may solve your problem.

EDIT....Also, measure your expander in the sizing die. Measure your trimmer pilot. Pilot should be a couple of thousandths less than expander. If not, do as "rg" suggest with the drill motor trick. I've done that to a few factory pilots. Then I just said screw it and quit buying them, and make them myself.


JM2c

[RiskyBusiness]

If you trim them all to match shortest case you will be GTG. As rg1 correctly stated, SAAMI case length spec is 1.730-1.760".

Is it the pilot that is binding on your trimmer? Cutter shaft is same as my Forrester. Very shallow chip clearance flutes. If you take a big bite while pushing hard. The chips bind in the shallow fluted face of the cutter. Made worse on mine, because I unscrewed the handle and use a cordless drill motor as a drive for it.

Try not pushing as hard and after each couple of turns, retract the cutter 1/4" or so while turning, to clear chips and go again. That may solve your problem.

EDIT....Also, measure your expander in the sizing die. Measure your trimmer pilot. Pilot should be a couple of thousandths less than expander. If not, do as "rg" suggest with the drill motor trick. I've done that to a few factory pilots. Then I just said screw it and quit buying them, and make them myself.


JM2c

Thank you! going to measure the expander on the sizing die.

[RiskyBusiness]

If your pilots for your Lyman Universal Trimmer were like mine they were too large and would hang in the necks. My solution was to put the pilot in a drill and using a smooth file with sandpaper wrapped around the file to reduce the diameter until they slide easily into a tight case mouth. Don't want it too small but after sanding mine down a couple thousandths they work perfectly. Need to have a polished surface after finished without scratches on the pilot.
I would measure all the sized cases and trim the long ones to 1.750". I would not trim them all to the shortest length. The ones that are 1.740" after sizing I would not trim and would load them at the length they are. Specs for .223 Rem cases are 1.760 maximum minus .030". I don't like cases shorter than 1.740" but at 1.740" they are perfectly good and safe to load.

so helpful thank you. I also noticed if i chamfer the inside of the mouth very lightly it allows me to get the length desired when entering into the pilot. but ill see about sanding the pilot down by a hair. One last thing, theres a change of length after deburring/chamfering, should i adjust my trimmer accordingly because of this?

[bubbala]

<One last thing, theres a change of length after deburring/chamfering, should i adjust my trimmer accordingly because of this?>
if your length changes you're over doing it. just a light touch is needed.