New brass?

wisconsinteacher · Oct 18, 2013

I just got 100 pieces of Win 338WM brass today and want to prep it over the rainy weekend. I plan on sorting it by weight and resizing the brass to get the dents out of the mouth.

My plan is this.

1. Measure all the brass with a Hornady gauge to find where the shoulders are at. I am going to find the shortest length and then try to get all the rest of the brass to that size.

2. Trim all brass so it is the same length.

3. Weigh brass and sort it so it is with in 1% of the average weight of the lot.

Does this sound correct or am I missing something or over thinking something?

steve4102 · Oct 19, 2013

Chamfer and de-burr after trimming.

Guest · Oct 19, 2013

I think you'd be best suited to perform trimming, sorting, and shoulder measurements after first firing. Here's what I do with new brass:

Set up my die so there is a slight "cam over" compression fit with the press/shellholder. Resize every piece of brass this way initially.

Chamfer the inside of the case mouth, just to avoid shaving jacket material off the base of the bullet.

Prime and load as normal, remembering to drop back about 5% and work up, since it's new brass with unknown capacity/pressure signature.

Once you get the brass all fired once, you can check the shoulder length (should be uniform and set to your chamber now) and readjust your die to bump it .002" during sizing.

Once the 1x fired brass is all sized, you can trim it to absolute uniformity. Uniform brass is the ultimate goal here. After trimming, chamfer and debur the case mouths.

Now you're set to weigh and sort the brass if you'd like, though I don't generally weigh or sort brass for hunting rifles. No big deal if you want to. I just don't have time/interest. Some folks swear by it, though, so don't take my lack of doing it as gospel that it's worthless or bad. I just don't see the advantage in my own rifles so I don't do it.

If you trim your brass before you fire it the first time, you'll end up with a bunch of non-uniform brass after first firing, and some of it may be shorter than minimum case length for the round. I never trim before firing the first time on virgin brass.

Everybody does it differently, so you can certainly do it your way, and that's not wrong. The above thoughts are my method, and my opinion. Worth what you just paid to hear it, maybe more. Enjoy a good diversion on a rainy weekend, regardless!

wisconsinteacher · Oct 19, 2013

Great tip on the trimming. So far I ran it through the sizer to get the dents out. (they were bad) Now they are in the tumbler cleaning up. I will load them up and shoot them before I trim them and get them all the same.

Antelope_Sniper · Oct 19, 2013

My last lot of Winchester brass was very inconsistent on it length. Some was so long they would not chamber properly, so I'd test your 3-4 longest before loading to make sure they will chamber first, if you plan to trim after your first firing.

Guest · Oct 19, 2013

Good point, A_S. I'm in the position of not having bought new brass in a few years, after stocking up prior to the last shortage. As I understand it, QC is in the toilet on brass these days due to demand. Might be worth checking the long ones (post initial sizing, as sizing will change the case length) before loading to be sure they chamber.