ORIGINAL: statjunk
Hey guys,
I'm reloading for a 300 WM. I have a Lyman Universal Trimmer.
Yesterday I full length sized about 75 pieces of brass, cleaned them up and re-primed with winchester magnum primers. After I went through all this I measured a few and found hem to all be between .002 and .006 longer than the maximum case length.
So here come the questions:
1. Is that long enough to require trimming?
2. Can I trim brass that already has the primers in it?
3. What menthod do you guys recommend to get the trimmer set to the right lenth? Do you start big and continue cutting till you get where you want to be or do you use a caliper to measure the distance between the case holder and the cutting surface?
4. The manual says that max case length for the 300 is 2.62. So does that mean I need to cut the cases back to 2.60?
5. Anything else I need to be aware of?
Thanks
Tom
Yep, I would trim all to 2.60". Yes, you can trim primed cases, but desirable for them to be unprimed. You just need to make sure the primer isn't extruding past the rim. You can rub your fingers over them to make sure. If the primer is not deep enough, it can affect your case length measurements.
To set up you trimer, there should be two adjusment rings, one fine and the other course. YOu want to play with your trimmer and have the find adjusment set back as far as possible. So turn the small ring counterclock a few times, this will give you adjustment for the cut. Push the cutter against the face of a case that needs trimmed. Tighten down the screw holding the large adjument (coarse) in place with teh cutter against the case mouth. Now screw down the small in 1/4 turns and tighten down and cut. Measure and adjust and cut. Do this until you get it right for two cases.