Trimming brass

[Coyotecontrole]

Im new to reloading and i want to know when i should trim my brass. My fired one time shell dont show any sine of strecthing.

[Bill K]

You will not know for sure the length, unless you measure it. just looking does not really tell. Trim and keep it within the limits for that cartridge, then you know you are running it safe and within limits. Bill K

[futuretrades]

I am guessing, you are talking 204R. Your brass in the 204 does not stretch much, unless you are loading "HOT"

If you don't have a caliper, get one. A caliper is the only way to get an accurate measurement, other than a micrometer, to check the length of said brass. No need to trim until brass is about .010 over max length. At that time, only trim back to minimum length, which is shown in your reloading manual, or trim back to the length of your shortest brass.

[RAMOS]

Measure your chamber length and trim a couple thousandths shorter than that. Published 'trim-to' length is most likely shorter than needed.

[Coyotecontrole]

I am a 204r shooter and i do own a caliper. All he reading I have done made it seen like id be trimming every reload. To tell ya the truth I've measured 150 cases so far and not one was longer of ever the same length as new brass. All slightly shorter. Is that normal

[Nor Cal Mikie]

Most chambers are "about" .020" longer than Max Trim length. Best to measure your chamber write that measurement down and refer to it when you start checking brass at reloading time.
I have BR brass with 20 to 25 + reloads on them and they still don't need trimming. I use bushing bump dies that keep the cases from growing.
Sinclair Int. makes chamber measuring plugs so you'll know the actual "measured" length of your chamber.
EVERY one of my chambers is measured and that measurement is written down so there's no guess work when it comes to trimming or not.
At the same time, measure the freebore so you know how to set the OAL to reach the lands, or not.

[Jim White]

As mentioned, spend the bucks and buy a good quality set of calipers.

A handy tool that gives a visual reference for case OAL (Min & Max) and sizing (over & under) is a "Wilson Case gage". I have them for all of my calibers except 20VT.

HTH

[DannoBoone]

Any brass I've bought the past few years is all shorter than my Hornady handbook states
for "trimmed" length. Keep wondering WHY?

[futuretrades]

Any brass I've bought the past few years is all shorter than my Hornady handbook state

That is a very good reason to Fire Form your brass before you even think about trimming that precious brass. Once fire formed, check for need for trimming, but my guess is you still will not need to even trim the longest piece of brass. And if you only neck size your brass, it will be a long time before you need to trim. It is a good idea to check tho, so you can keep track of what is going on with your brass. Full length sizing will cause your brass to stretch each time you run your brass thru that FL die, thus the reason for neck sizing.

Just my 2 cents