Case trimming 101 help please

[Wee Hooker]

I've been reloading for close to 20 years but about 99.9% of it has been for pistol ( OK, and a few with new/unfired rifle brass.) So, while I have a ( used Lyman universal) case trimmer, I don't know much about the in's and outs of using it beyond set up.
Specifically:

1) I'm assuming your supposed to trim your cases before sizing or is it supposed to matter? ( My sized cases fit TIGHT over the collet.)

2) Once I trim to length , the case mouth seems smooth & shiny but has a SLIGHT ridge on the outside "edge." Do I need to perform another operation or is this the sign of a dull cutter?

3) How often do I need to change cutters? Can they be sharpened?

Any insight to this part of the operation is appreciated.

 

[freedom 475]

You need to twist the de-buring tool around the outside and inside of the case after trimming... That's the little "rocket" looking tool.

 

[sourdough44]

Trim to lenth after sizing. After trimming you 'champher & debur' to get rid of the sharp edges.

 

[Gun 4 Fun]

Most cutter heads will last virtually forever if you are only trimming brass cases. As freedom 475 said, you ned to use a deburring tool to chamfer the case mouth inside and out.


Hey freedom 475,

Welcome over here to this forum! We actually met over on TFL. I have your forum name as part of my e-mail.

 

[s&wchad]

Trim to length after sizing. After trimming you 'champher & debur' to get rid of the sharp edges.

+1

Firing causes cases to stretch and full length sizing does too. Trim and deburr after sizing. Watch for thinning and separation at the case head. If you always shoot the same case in the the same rifle, you can neck size instead of FL sizing and your brass will last longer (and you won't have to trim as much). Full length sizing is recommended if you're hunting dangerous game and pretty much mandatory if you shoot the same cartridges in different guns.

 

[Wee Hooker]

Ok Gents thanks, Guess I need to get ANOTHER tool. Got to say, there are an awfull lot of extra operations required on each case as compared to handgun reloading! :-(


As for trimming after sizing, is it normal for the pilot to bind in the case mouth? Seems like too tight a fit as it wants to stop the shaft from turning. Maybe I need to polish the pilot?

 

[Gun 4 Fun]

Dave, most pilots are a few thousandths under nominal bullet diameter to prevent binding. Polishing your pilot will help. So will running a case neck brush in and out of each neck real quick. Chuck your pilot in a cordless drill and use some 320 grit emery cloth to polish. I just hold the cloth with my fingers in my free hand. You aren't going to remove much metal, so heat isn't really an issue while holding the cloth. Measure the pilot with some accurate calipers before you start, and then check often. It'll only take a minute or less to do.

You don't need to trim every time you reload your cases. I load a lot of high pressure rifle rounds that have the ability to really stretch the case, and even with them, I only need to trim every 4-5 reloads. Just keep an eye on them, and don't let them exceed max length before you trim.

Neck sizing only can almost eliminate trimming, but the cases will only fit the chamber they were fired in reliably.

 

[gregintenn]

Chamfering case mouths not only removes burrs left by the trimming operation, it also makes it somewhat easier to seat the bullet. I like to trim every case every time; especially if I intend to crimp. When all your cases are the same length, you have one less variable to worry about. Consistency is the father of accuracy.

 

[Gun 4 Fun]

In several hundred thousand rounds loaded and fired, I have never seen the need to trim every time. If your chamber and dies are correctly made, your cases should all grow at approximately the same rate, if all are from the same lot.
I rarely crimp with rifle rounds. I only do that for lever gun rounds. I do not crimp for my really big bore rifles, and have never had any creep or setback.

 

[thomashoward]

Ok Gents thanks, Guess I need to get ANOTHER tool. Got to say, there are an awfull lot of extra operations required on each case as compared to handgun reloading! :-(

If you get into Varmint or Benchrest there is even more

 

[freedom 475]

Thanks for the welcome Gun 4 Fun!!!



One thing you might check if your pilot is sticking..Is your pilot "all" the way in flush to the cutter head? You may have just a little space between them that is a allowing a small burr to form over back edge of the pilot causing your cases to stick on the pilot.

 

[David Sinko]

I use the Lee method with a drill. It's easy and pretty much foolproof.

There are times I'll trim before sizing, like when converting .308 to .300 Savage. It makes cutting the excess so much smoother and they end up the proper OAL anyway.

Dave Sinko

 

[s&wchad]

As for trimming after sizing, is it normal for the pilot to bind in the case mouth?

You do know that the pilots are caliber specific (they're typically marked)? Mine fit fine w/o any modification, but they're like me (old).

 

[OKFC05]

If you're new to rifle loading, you need to learn about case head separation. You trim from the front end of the case, but the brass stretches back at the REAR just in front of the web. Over sizing causes it to thin faster.

A faint bright line all the way around the fired case just in front of the web indicates incipient case failure. The failure mode is that the case head comes out and the rest of the case stays tightly locked in the chamber. Time for a case extractor, then.

 

[Wee Hooker]

Thanks for the education Gents,

p.s. Yes, I do know they are caliber specific. I'm using a 30 for 30 cal carbine. They only stick on the sized cases.