Do I trim new factory brass?

[RogerDat]

Not trimming saves a little time but having crimps that are all over the place is as annoying as having your ex mother-in-law standing behind you telling you how to clean your guns. If necked brass is sized, and trimmed to consistent length before use, then fire formed to chamber they should be very consistent from then on, and if caliber will only be fired from same chamber you can neck size only and have ammo matched to your rifle. Brass should last longer that way too.

Neck sizing is not recommended for auto loaders as I understand it. But it does well in bolt actions for me and lever guns too from what I have been told.

BTW - what is this new brass of which you speak? And where does it come from?

[rigger]

I run them through a sizing die but don't trim till after I've shot them once. I trimmed a new batch once before firing them and they all came out short once they had been fired. I had to keep them separate from my other cases due to the difference in length.

[northernlead]

1.270ish ,trim to length is 1.275,these were Starline,same with .44 also short.Double checked with two calipers.

[Tripplebeards]

I size and trim mine when brand new and after ever firing. Makes everything more consistent for better groups

[MostlyLeverGuns]

First determine chamber length. Most new brass needs some sizing to round case necks. Measure new brass case length. If longer than CHAMBER length (unlikely) or if lengths vary more than a thou or two trim. I usually pick the shortest case, just touch it to square mouth and trim the rest to match. If brass is uniform and not too long I load - chamfer, neck expand... Many chambers are very long compared to the 'book' trim to length, I have a couple close to a tenth ( 0.1) so most trimming is for uniformity and so you buy more stuff. Crimping does require uniformity with the tube feed lever guns. Knowing your actual chamber length can reduce a lot of brass cutting. NOE doe make a plug to measure chamber length if you don't figure out another way.

[wistlepig1]

I always FL size and trim. Even the ready to go brass isn't ready to go IMHO. Right or wrong, that's how I was taught by my father and have always done it that way.

Right or wrong, this is what I do on any new brass.

[725]

New brass gets the whole shebang. Straight walls get less than bottlenecks as they get used.

[jetinteriorguy]

The only brass I don't bother trimming is 9mm. All my revolver brass gets sized and trimmed once, I need a good consistent crimp since I shoot them in both revolvers and levers. All bottlenecked rifle brass is full length sized and trimmed and then checked every time in case it needs trimming.

[ulav8r]

Not trimming saves a little time but having crimps that are all over the place is as annoying as having your ex mother-in-law standing behind you telling you how to clean your guns.

If she bothers you that much, you should not have married her after getting rid of her daughter.

[earlmck]

I'm with rigger--I always shoot at least once before trimming. Run 'em thru the Lyman "M" die to round out the neck; a bit of champfer, and load and go. But I also seldom crimp my rifle reloads -- you sure as heck won't need to crimp that 25/35 to keep the bullet in place. Long neck, mild recoil: bullet isn't going to move.

[Griff]

As others have said, FL size, trim to length, chamfer and de-burr, then load. The last package (100 pc bag) I opened up had dents and dings all over the cases, especially the mouths. If you're buying your brass in 20 round boxes, maybe it'd be better protected, but bulk brass, you just never know what else was packaged with it, or what was stacked on top of it all thru the shipping from factory to distributor to you.

[northernlead]

,I
brought some starline and lots of them were short,but after resizing they were ok to trim to length