Trim or not trim brass?

[millhouse961]

I am brand new to re-loading, have my bench all set up, deprimed a test piece of brass, trimmed it, deburred, everything looks good. Was watching a couple youtube videos of guys operating the lee classic turret (which I have) and I noticed the would start with depriming and go through the whole process coming out with a complete cartridge. Doing it this way there is no step to trim the brass, is this not always necessary?

[Hunter47]

It depends. For auto loading rifles you must stay within specs. Consequences can be devastating. For bolt actions you can measure the maximum case length of your chamber and in most cases factory chambers are generous. Measure you brass after full resizing for rifle and resize it if you need to. For Pistol I usually don't trim (especially for revolvers) but I'll let the pistol shooters weigh in.

[mike.h]

I don't trim pistol brass.

[pdq_wizzard]

I trim all my rifle brass (even if it is with in specks) I like them to be as close to the same as I can.

I have never trimmed pistol brass.

[millhouse961]

ok you all bring up a great point I failed to realize: the video I was watching he was re-loading pistol brass. That explains it. Thanks for the info!

[HighLander51]

You don't trim pistol brass.

[Bill Steele]

While I agree with the "no trim" for handgun brass, the exception for me is I do trim revolver cases. I am not focused on a specific dimension as much as I want them to be as consistent as possible in length. When roll crimping, you get better results when starting with consistent length brass.

But in general, no trimming required for straight wall handgun brass, always trim (or at least measure to assure you are not past spec length) when you F/L size bottle necked rifle cases. When I neck size bottle necked rifle cases, again no trimming required.

[Fishslayer]

I trim & chamfer pistol brass if it's going to get roll crimped. Much easier to get consistent crimps that way.

EDIT: HA! Bill beat me to it...

[M1NM]

Depends on the caliber & Brass. Always had to trim my 30-30 but haven't needed to trim 30-06. Might be because they are military cases (harder than commercial brass)

[Munk]

I don't trim my straightwall brass, but I have started checking my .460s&w after a few firings just to see how its doing. Haven't had cause to trim it yet.

Bottle-neck brass gets trimmed after their first firing (or if using brand new brass, right after FL resizing for the first time) and I check to make sure they're not so far out of spec. This usually amounts to a trimming about once every 3 firings for some headstamp/caliber combos (differing brass thickness/consistency results in different amounts of brass lengthening) and sometimes as often as every firing for the ones that shift a lot (in some of my .30-30 loads).

[BisDak]

You don't trim straight wall pistol brass. The more you shoot them, the shorter they become.

Necked case (most rifle) brass is the other way.

Measure it.


.

[russt]

I trim all rifle brass, and any pistol brass that gets roll crimped.

[koehn,jim]

I measure the brass and trim as needed. For my rifles I use the Rcbs x dies and once set up no trimming is needed for the life of the case.

[bigchinner]

I haven't trimmed any of my 40sw or 9mm brass, as of yet. However, some of my 38special cases are looking a tad long. I think I should trim 1mm or so.

[Exodus343]

I trim all my rifle brass uniformly for accuracy and consistency
Can't say for handgun, don't load it