Do I trim new factory brass?

[novalty]

I just received my new Winchester brass for reloading 25-35 in my Grandmother's old Winchester '94. For those that have loaded for this, do I trim the brass to a set length before loading for the first time? If so does anyone have a case length that they should be trimmed too. From a quick internet search I am finding a Case length at: 2.043.

[6pt-sika]

I personally do not trim new brass until after I shot it a time or two . Some folks do I'm just not one of them for a lever gun !

[6pt-sika]

I go by whatever the loading manuals say and if it says 2.043" I would most likely trim to 2.040" .

[Omnivore]

It depends. If the new brass is all of the same length, and close to the listed trim-to length, then it's probably fine and dandy. You'd have to measure enough cases to see if they're consistent.

You need a consistent case length to get a consistent crimp.

If you're crimping into a crimp groove, then of course a consistent case length will mean consistent placement of the groove relative to the case mouth during bullet seating. If you set your seating die to place the front drive band almost touching the case mouth, and you insert a longer case, you're now jamming the case mouth into the bullet's drive band. Stuff like that.

I have some new Winchester cases, some of which need to be trimmed, and some of which are too short to get a proper crimp. I also have some Starline brass that is very consistent, so I don't have to mess with it.

It can get more complicated than that, depending on your chamber dimensions and the bullet you're using, but those are the issues I'm dealing with on the 30-30 and the 10mm Auto. If my cases are consistent within a few thou, their exact length is not so important in my situations, but in others, the exact length may be an issue.

[MtGun44]

+1 on omnivore

Bill

[shredder]

All the new brass I have ever used came with out of round case mouths and very rough edges. I can not imagine how anyone could seat a boolit without a trip through the resizing die(backed out 1/2 turn), trim and chamfer/deburr. Then you are starting with all your cases exactly the same. Just my 2 pennies.

[dragonrider]

New brass needs to be sized then measured for length, trimmed if needed according to what Ominvore posted above.

[novalty]

Thanks for the advice. I'll put it through my sizer die first and measure and proceed from there.

[dragon813gt]

I FL size, run them through the trimmer and then chamfer. It takes me just as long to measure them as it does to trim. If they're short than they aren't trimmed so no big deal. I only do this for bolts/levers. For straight wall pistol I just size and load as normal.


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[pietro]

all the new brass i have ever used came with out of round case mouths and very rough edges. I can not imagine how anyone could seat a boolit without a trip through the resizing die(backed out 1/2 turn), trim and chamfer/deburr. Then you are starting with all your cases exactly the same. Just my 2 pennies.


. +3


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[Chill Wills]

I like to fit my cases to the chamber of the rifle it will be fired in. Especially for use with cast bullets which do not like to jump the gap. Double especially, you should check the needs of your rifle if it is an old rifle. Some of the older rifles are found where the chamber lengths where not held to modern standards, in other words, "loading book trim to lengths". (I mostly shoot 100+ year old rifles rifles)

As a mater of practice I have found even current production rifles have correct length-plus chambers running 0.025 to 0.035" too long. By trimming to stated length you end up with short cases. Your rifle does not know or care what the book said. When handloading and especially for cast bullets, we can accommodate this to our advantage to produce more accurate, less leading ammunition.

I won't go into how the correct length is determent. Plenty has been written elsewhere about that. You should trim to what ever the "book" says if that is beyond your handloading at this point in time.

There are many benefits to having the correct, full, safe length cases when shooting cast bullets.

[OverMax]

novalty wrote: Thanks for the advice. I'll put it through my sizer die first and measure and proceed from there.
Excellent idea running all the brass thru a resizer first. Then you can trim them anywhere between 2.020 and 2.040 just so long as they all are the same length after trimming is what your looking for.

[geargnasher]

+1 to all the previous posters who mentioned fitting the brass to the chamber. How will you know what your trim-to length is without knowing the length of your chamber, especially on a very old gun? A chamber/throat cast or impact slug is in order.

Gear

[rintinglen]

Heck yeah. Brass varies in length way too much not to trim it. A while back I measured 100 38 Special cases from Starline. None of them was long enough to exceed the trim to length and what I had measured ftom 1.133 to 1.146. If your brass starts out all over the map, your shots on target will reflect that.

[TXGunNut]

Most certainly! At this point I'd want to establish a baseline. First, measure each case to ensure none were over max. I'd fire each case with a starting load then resize and trim to SAAMI minimum length. WW and RP factory cases have been a bit troublesome for me lately; awesome brass but lengths vary. I'm fussy about case lengths on cases that require a crimp.

[northernlead]

I shoot 45c out of a rbh,bought some starline brass,over half were shorter than the trim to length in the manuals.Can I just trim to the shorter length and load?

[zymguy]

I shoot 45c out of a rbh,bought some starline brass,over half were shorter than the trim to length in the manuals.Can I just trim to the shorter length and load?

How short are we talking?

[osteodoc08]

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.

[Tom W.]

Just bottle neck rifle brass. Size first then trim. My .270 was bad about having to trim every other loading. My straight wall pistol and revolver cases never again. I did that once to my .44 brass while recuperating from surgery. Yes, I was bored. Never again....

[gnostic]

I give new rifle brass the whole treatment, trim after sizing, case mouth bevel, flash hole and primer pocket.

[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.:bigsmyl2:

[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