Out of 6MM Remington Brass

GregShooter

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Can 257 Roberts brass be used as a suitable substitute for 6MM Remington brass? If so, is there anything unusual about the re-sizing process I should know about? Thanks for any input and advice from anyone.
 
Can 257 Roberts brass be used as a suitable substitute for 6MM Remington brass? If so, is there anything unusual about the re-sizing process I should know about? Thanks for any input and advice from anyone.

yes you can, but the cases will come up a little short after fire forming. Not a big deal as the neck length is already long to start with. Personally, I'd cut down 30-06 or .270 or .280 brass and make my basic case as long as possible to make them come out as close to 6mm brass as possible. Anyway I used .257 brass to make 6mm cases, but they come in about .025" short. If your using a factory chamber (like Remington or Ruger), they are often reamed .05" too long at the end of the neck, so take full advantage of this if you can. That way the fire formed case will come in right on size after trimming.
gary
 
How much of a process is this? i'm not out of brass yet but I can see it on the horizon.

Considering your other options, too much of a process. Pushing a shoulder back .200" and ending up with a quality job that doesn't require fire forming will require some forming dies. You'd be much better off to use 257 Roberts or 7mm Mauser brass. Or you could check the websites of the obvious vendors every couple of days for the real thing.
 
How much of a process is this? i'm not out of brass yet but I can see it on the horizon.

Here's how I'd do it (.270 brass):

1. anneal the case necks and shoulders a little on the heavy side (they'll work harden during the reform operation)

2. run the well lubed (use Imperial wax) thru the 6mm die till you run out of room.

3. trim the cases back as much as you can, but leave plenty long

4. run the cases thru the die again, but leave them a tad long at the shoulder and an over all length of maybe 2.400".

5. this is the finished part and can make you some really nice brass, or junk. Find out exactly how long the max over all length of the chamber is (not the throat). Now finish form your brass to get the correct headspace, and trim it to where it's about .015" shorter than the actual chamber.

6. your ready to finish fire form, and trim back to the correct 2.235" over all length. I would go ahead an anneal the case necks and shoulders one last time as we've moved a lot of brass! I'd also expect to have to shave the necks as there will be plenty of brass flow up there. These cases ought to come out better than factory 6mm brass as they're built for your personal chamber.

of course this is a little more work, but still isn't hard. The two anneal processes are critical, and will make the case fire form better in my book. I had some problems with reforming .257 brass even though I've never eluded to it in the past. The cases come up a little short, but that's not so much the issue as burning a groove in the chamber neck when using some fairly hot burning powders. We spend a lot of time and money getting as perfect a chamber as we can, and then turn right around and screw it up in 400 rounds! Still the 6mm case is not a barrel burner in anyway like some other 24 bore rounds.
gary
 
lastly (I forgot to add this).

there a small company named Blue Star in Arkansas that has a lot of new and once fired brass on the shelf. I've bought new and once fired brass from them in the past, and they're strait up folks
gary
 
Considering your other options, too much of a process. Pushing a shoulder back .200" and ending up with a quality job that doesn't require fire forming will require some forming dies. You'd be much better off to use 257 Roberts or 7mm Mauser brass. Or you could check the websites of the obvious vendors every couple of days for the real thing.

I look regular but not hard. Baby my last 100 and re-barrell might be what happens.

Factory Winchester ammo is available at times.
 
Tricky,
I know this post has some dust on it but want you to know that Blue Star went out of business over a year ago.
 
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