I have done the action work on one Mauser, but I have not put a barrel on it yet. (It may be a while...) So this advice from a rank beginner.
The best advice I can give you is to get one the $400 custom trigger guard/magazines that fits the cartridge, then open the action up to fit. If you can't start with that, then you shouldn't try to play the game. (I did not learn this until 'way too late.)
Hopefully 90% of the metal will be removed from the rear of the action. ( I at least got this part right.)
Get Jerry Kuhnhausen's book on Mausers. Midway has it, as does Brownells. He's an expert, and he'll tell you not to do it.
Good luck,
Don
Jason
I agree that it's fun and it keeps you busy. I have not given up, although it now appears that I will wind up with a blind magazine and self-reworked military bottom metal, since I opened the action further to the rear than Blackwell or Sunny Hill magazines fit.
I just wanted to see what I could do.
Don
I also asked this question a while ago. The solution I've come up with so far is to use a US Enfield P14 action. There are still a few around, they run about $100.
I was thinking quite hard about doing what 358mark has done, cut two mauser actions and make a matched pair, but decided that should be a project for later. Gun Parts sells a magnum magazine box for the enfields ridiculously cheap, like $8.75 or so. Might want to get that then eyeball it to see how you can get it to fit dimensionally. What sort of mauser action were you planning on using?
JAG
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Ray Atkinson
It won't fit mine that is opened to the rear. I think I will go with a blind magazine.
Don
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"If you can keep your head about you when all others are loosing theirs and blaiming it on you..."
Sounds like to me you measured a std., or short mag. box...You are supposed to use a long mag. box and open the action to fit it and widen the rails. With your Sunny hill perhaps it needs to be set back by openning it up and rewelding.
You take all the lenth out in back and less than 75 thousands in front and thats nothing...
Also any magazine can be altered in any direction...lenth or width...
Holland and Holland lenthened and widened standard 98 magazines to drop box and 375 lenth and took only a smidgeon out of the feed ramp, mine is less than 100 thousands..They did excellent work that many US gunsmiths have not figured out to this day simply because they never took the time to study the English guns, or didn't know what they were looking at....
If you want the measurements I will be glad to forward that information to you....Better to get a Precise box that is so designed as I understand it....D'Arcy Echols makes one also but I don't know if he sells them...
These boxes are the reason the old English guns never had a feed problem..Better yet find and old English gun and take it down and study and take the measurments off of it..H&H, Rigby, Westly Richards and a few others.
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Ray Atkinson
I had a Sunny Hill drop bottom 375 length Magnum magazine box in my hands a week ago. It was a beautiful piece of work. The fit of the parts was outstanding. You literally could not see the seam where the trigger guard latch fit into the trigger guard. I sent it back because it didn't fit my modified action, not because of any fault with the workmanship. I had told Andy at Sunny Hill what I was up to before he sent it to me. He was very helpful and friendly, even though he knew there was a good chance it wouldn't fit.
The mag well was 3.615 inches. The rear wall of the magazine box went exactly into the rear slot on an unmodified 1909 Argentine when the screws were started in their threads. To me that means that to use the box you'd have to open the action up solely from the front.
I would not pay $465 for a trigger guard I had to modify to fit my action, though. My 1917 Oberndorf GEW has already been opened to the rear as you describe. I think I had to take .065 off the front ramp - but I may open it up to take 3.66 OAL (right now it's a no-margin 3.65) which would put me right at your .075 number.
I may take you up on the offer of free advice if I start actively working on it again, thanks. Right now I'm too broke to pay attention.
Don
The answer to your delima is to buy one from Jim Weisner at Precise or I believe Ted Blackburn..Give them a call, there made right and for that spicific purpose.....be sure and tell them exactly what you are doing...I really like Teds work....
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Ray Atkinson
I have already talked to Ted Blackburn, Darcy Echols put me on to Ted about a year ago. I got the impression that Ted made the trigger guards for Darcy when he was still doing Mausers (I may be wrong about that...) Ted was very nice and took time to talk to me at some length. I have not measured his trigger guards, but the chance of my already opened-up action being an exact fit is pretty slim.
Besides that, I really can't afford Ted's work.
Having a blind magazine is no real penalty to me, so I'll just have to keep trying until I make one I like. I used to be pretty good with a TIG, but I'm badly out of practice, and free time is in short supply.
Don
If I knew more about it I would tell you, but since I'm just learning, even the following vague description is liable to be bad advice.
I know that opening a Mauser up to the rear leaves a stronger action, but it means that you have to work on the ejector, and bolt stop as well as opening up the bolt face to the magnum dimension and truing it. I welded on a Brownells bolt handle.
The rear bridge gets milled to the FN contour (in height), then the ejection port is increased by moving the opening back to the back of the stripper clip slot in a smooth sweeping curve. It has to be long enough to cleanly eject a full length loaded round. After that the extractor was too short (didn't reach to the rear bridge) so I cut up a broken extractor and welded the back section onto the back section of my good extractor. I used slivers of the old extractor as my welding rod, and kept the front 2/3 cool while I welded it.
The body of the magazine needs to be 1.866 times the diameter of the cartridge (or a couple thousandths less) at the back (base or belt) and at the shoulder. This was worked out by Paul Mauser long ago to get reliable feeding with the shortest stack height. The sides of the magazine need to taper at the top to meet the bottom of the feed rails.
How to open up the feed rails is really an art. I won't be sure I did it right until I get a real barrel on the action. I made some dummy rounds and a dummy chamber (out of oak!), then whittled on the rails very slowly until it fed right. I asked everybody's advice, then sort of filtered it until it made sense to me. If you do it wrong you have a very expensive and funny looking single shot!
HTH,
Don
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Ray Atkinson