Brass Trimming

[hogcarpy]

Folks,

I'm a fairly new reloader. I've reloaded about 1000 rounds of pistol cartridges and just started reloading rifle rounds. I'm currently working up a load for 300 WSM. The Hornady and Nosler manuals call for a trim length of 2.1".

I've got the following brass at the stated trim lengths...
20 rds Federal @ 2.09" (once fired)
80 rds Nosler @ 2.1" (once fired)
25 rds Nosler @ 2.08" (brand new)

Do I trim the Noslers (once fired) to 2.09" assuming the new Nosler brass with lengthen after firing? Or trim everything to 2.08"?

 

[Bigjay73]

Id trim all of the nosler brass to 2.1 and not use the rest. I think using uniform brass makes a difference. And imo, nosler brass is pretty damn good

 

[Jordo5220]

I wouldn’t trim any of it below what the manual says, the cases will stretch over time and need to be trimmed. No need to add the extra step now if you are under spec

 

[Laelkhunter]

I don't trim new brass before loading. I have found that the case seems to stretch the most on it's first firing. I would trim it after the first firing to the recommended trim-to length.

 

[MThuntr]

Here's my take...don't mix headstamps aka get rid of the federal brass

Fireform brass using whatever method you so choose. Size your brass...I tend to start with a shoulder bump (there are hundreds of threads and videos). Set your trimmer to 2.09 and get any of the brass that may be a touch long and start your load development.

 

[44hunter45]

A couple of things:
Start thinking in thousandths of an inch. Not 2.1" or 2.10" but 2.100". If you do not have a caliper that reads in thousanths, get one. The SAAMI listed maximum case length for 300 WSM is 2.100"

This is important. 2.100" is the NOT the trim length, it is the MAXIMUM case length. If the chamber in your rifle is cut to minimum SAAMI dimensions or less, you can get excessive pressure as you approach max case length.

We want to get all our brass to the same length somewhere between around .010" less than the maximum. Hence the manuals saying to trim to 2.090"

It is much safer and more consistent to have all your brass shorter, but the same.

Do I trim the Noslers (once fired) to 2.09" assuming the new Nosler brass with lengthen after firing? Or trim everything to 2.08"?

Trim the fired ones to 2.090" and do not trim the new ones.

At this point that is all you really need to do.

There are several threads here on HT about trimming standards and tweaking extreme consistency out of your loads.

Try typing "trim" in the search button on the upper right, near you login info. You will get list of many thread about it.

Welcome to handloading, it can become an addiction.

 

[WapitiBob]

Your case neck id/or chamfers need to be as consistent as the overall trim length; the end of the case is sitting in space.

 

[std7mag]

I check the trim on all my rifle brass.
Even new brass, as i've found some that have needed it.
Personally i use the Lee case length gauges. 1 for each cartridge that i load for. Easily stores in an index card file box.
Set the trimmer up, run each case through it after sizing.
No guessing of should i trim or not.

Note.
AI cartridges do need trimmed also. Just not as much taken off as standard cartridges.

Cases like 223, 308 can be checked every other loading. I'd advise doing magnums every time.

 

[lifesupport4u]

Have you already resized them? If not do that and then trim. I use Lee case trimmers... simple and accurate.

I also weight sort and use matchesd head stamps for hunting ammo.

 

[Bigjay73]

I weigh mine too, another reason I like Nosler, very uniform weight

 

[hogcarpy]

Thanks for the help fellas. I will

Have you already resized them? If not do that and then trim. I use Lee case trimmers... simple and accurate.

I also weight sort and use matchesd head stamps for hunting ammo.

I've sized them and I have a Hornady case trimmer.

 

[hogcarpy]

Thanks for the help fellas. I decided to trim any long cases to 2.09 and live with the new brass for now. I'll shoot the new brass this winter as I develop a load.