Home Forums Reloading Big Game Rifles fire forming brass

Can aged brass even annealed not move much with a max load and bullets touching lands ? This is LC .30-06 brass. Also virgin Winchester .270 Winchester brass. I didn't anneal the .270 brass. Same deal with the .270 max load and bullet touching lands.

What are you trying to do?

I was told I have a tight chamber.

I'm thinking I do..... SAMMI says 2.048 max 2.058 min I measured with my Hornady HS gauge on my calipers with my Forster NG gauge and it measures 2.044. My fired case measures 2.041. I remember bumping back .004 to chamber. And the bolt is a little stiff closing with 2.041.

RCBS says the zero on their precision mic is 2.048 and the gauge reads .005 which would be 2.053 on the HS gauge, but the Hornady reads 2.044. I did some math, (took the difference between the part of the RCBS gauge outside the case, only from the datum and the case head, subtracted those lengths) and both gauges read a case the same according to gauges and RCBS's instructions.

BTT

I've never used or seen the RCBS tool so have no idea about it. The Stony Point (Hornady) gauge is but a comparator. It may or may not (most likely not) read to the SAAMI datum point on the case shoulder.

OK, so why is this important to you?
I see no problem with a tight chamber, as long as you can resize the brass to fit it, and as long as factory stuff, if needed, will chamber.
Personally, I take no measurements of my cases, other than OAL, instead using the rifles chamber to tell me what it likes. I usually push the shoulder back about 3thous. I stick a piece of Scotch tape to the case head, that`s about 3 thous thick, and close the bolt. If needed, I will push back the shoulder until the bolt closes easy, or just smeering the tape. I then try about half of the sized cases for fit, and adjust if needed.

Keep in mind that different brands of brass may size differently, even when annealed, so after sizing one or two, try them in your rifles chamber.

With SAMMI chambers just surprised with a chamber that would be tight.

I'd question your tools and your measuring technique. Are you a machinist that uses precision measuring equipment day to day? I'd read CGPAULS post above, as he points out some valid explanation and advice. Personally, I'd give 2 chidts about it, if you can chamber and fire factory ammo. That means there is no issue with your chamber. Measure the factory stuff and see what it tells you. If it does not chamber factory ammo, then there is an issue. This is a good reason I generally say some of you guys need to leave all that fancy measuring schidt alone and get back to the basics..

If you are questioning my tools and my technique then let's hear it.


Some brass takes more to form than others. Just curious about someone mentioning about a tight chamber somewhere else but here. Just ruling out inconsistences with load procedures that's all.


A tech from Sierra.....said this

I’ve noticed that brass sized from a different cartridge, or necking up or down in diameter, even when new, needs to be annealed before the forming and 9 times out of 10 needs to be annealed after also. I’ve had match brass from the 50’s that took several sessions to make it soft enough to work with. It was used brass with a lot of time on it, and I found it to be specialized because the rim didn’t have a bevel on it. Other than that, it still worked. Let me know how it goes for you, I’ll be interested in hearing back if this brass can be salvaged.

My experince from forming brass is consistent with the Sierra tech comment. When making 25 WSM brass from 300 WSM I first anneal (propane torch technique). Form to 7mm WSM and 25 WSM then anneal. I have also found Imperial Sizing wax is the best lube.

Hardened brass will move less that soft brass but then you already know this.

Here's a trick: take an empty primerless 9mm case and drop it over the neck. The case will pick up a datum line on the shoulder. It's a tricky measurement but it sounds like you're up to the challenge. Note, measure a case fired in your chamber then measure after you resize.

I'll try and remember to pick up a 9mm case next time I'm at the range

Measure a datum line on a fired case. Size in a die set generously long. Incrementally size the case adjusting the die tighter until it stops growing at the datum point and bumps back one thousandth less than initial measurement. That is exactly ALL you need to do.

I don't agree
I don't agree with you. The shoulder isn't moving much but I know the body is. Why else would a NG gauge have a smaller diameter body ? To only measure from the head and shoulder.. that's why. I bet you that if a die, like a body die, only sized the body completely and not the shoulder you would see what I'm saying.

Well, ok then.

Case closed. Pun intended...

And Mike S is an expert. Case closed Go away Mike

I HIGHLY DOUBT he understands what he's disagreeing with, but who cares. I don't. It's Friday, I have the WHOLE weekend OFF, and it's Beer O'clock. I don't give a single flying [bleep].

BYE

Guess numbers don't really mean much. I'm just backing off on a NG a few thou and calling it a day.