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7MM Mauser Help: Update

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15 November 2003, 11:55
C.S. Justice
7MM Mauser Help: Update
Got my no-go gauge from Brownells....... bolt closes EASY..... not what I was hopeing for!! Thanks to everyone for the ideas and help. CSJ
15 November 2003, 14:57
jstevens
If the bolt closes easy, you've found your problem. Ain't supposed to work that way, as in no go. I'd be happy I've found the problem.
15 November 2003, 23:16
C.S. Justice
jstevens,

Thanks for the reply, you are right I should be happy I've found the problem...... I should have checked the headspace before I bought it...... one of life's lessons I should have learned from my first wife..... just because something looks really good.....CSJ
16 November 2003, 10:55
BigBullet
CS Justice,

All is not lost my friend. A couple things to consider. What type of action is this rifle? Does the bolt match the reciever? What is the cause of the headspace problem. If the action is soft then you do have a problem and the rifle is a wall hanger, but if not, you do have a few options if you would like to shoot this rifle.

First of course is to have gunsmith tell what the problem with the headspace is. Lets say the metalurgy of the rifle is sound. And there are no other problems other then the excessive headspace of "factory" ammo. You already have fireformed cases, simply neck size the cases and you kind of have a "wildcat by necessity" and you shoot the rifle. Just do not set the shoulders back on the case.

Second option is rechamber the rifle to a factory cartridge that will clean out the old chamber, such as a 280 Rem. You will not have to set the barrel back on this and it should be an easy job for a gunsmith if the action can hold the pressure (not for Mauser 91,93, 94,95,96)such as a Mauser 98.

Thirdly is to set the barrel back and rechamber to your origional cartridge. Most expensive option.

There are always options,
BigBullet
16 November 2003, 12:18
C.S. Justice
BigBullet,
Thanks for the reply. I think I'll go with option number 1 for now, the rifle is 1908 Brazilian Mauser, all matching. If you go on LOOKS alone it is in very good condition. CSJ
16 November 2003, 16:11
bartsche
CS
When you next fire form Cases, using option 1, get some cheap heavey, long bullets.
Seat them out so that you really have to work to close the bolt, but make sure it really does close.
I recommend a medium burning rate powder like 3031 somewhat below suggested max.
The idea is to have an interference fit between rifling and bullet to give you a tight head space. You might try "lightly" crimping even without the cannelure.
I have used this technique successfully. [Smile]
17 November 2003, 01:50
C.S. Justice
bartsche,
I got an E-Mail earlier suggesting I size 8MM brass with my 7MM dies until the bolt just closes...... something I do with .270 brass for my 6.5-06 sometimes (usally neck-up 25-06)..... for some reason I didn't think of that.
I already have 7MM brass and some long heavy bullets...... I think your idea will work great, thanks. CSJ
17 November 2003, 06:39
<eldeguello>
quote:
bartsche,
I got an E-Mail earlier suggesting I size 8MM brass with my 7MM dies until the bolt just closes...... something I do with .270 brass for my 6.5-06 sometimes (usally neck-up 25-06)..... for some reason I didn't think of that.
I

I think this would be the best solution, starting of with a case that has correct headspace before you fire-form it to begin with! Like making .338/'06 brass from .35 Whelen cases....
17 November 2003, 12:28
C.S. Justice
eldeguello,
Thanks, I think you are right again. CSJ
19 November 2003, 11:59
marley
How about testing the electrician tape theory-

see how many pieces it takes on the shoulder and/or bottom of the no go gauge for the bolt not to close.