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#1 odies dad

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Posted 10 January 2007 - 12:47 PM

Since the Mauser supply seems to be drying up at the peak of my sporterizing fever, I thought I might think of reworking some other breed.
Of course I can't leave anything as is. That would be too boring and wouldn't antagonize a purist.
My idea is making a 45-70 out of a MN. I think the bolt head would be close enough. Some companies use the same number for their shell holders. A new barrel, a decent stock, etc.
Has anyone tried rechambering a MN? I'm trying to stay away from bolt face modifications. Feeding is an issue to be dealt with.


#2 z1r

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Posted 10 January 2007 - 01:10 PM

The .45-70 rim is like .605" and the MN is more like .570" you will need to open the bolt face up some.

i would think a .375 MN would be kool. The Finns neck the case up to .366" or 9.3mm.

#3 sonic1

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Posted 10 January 2007 - 04:26 PM

from what have tried and read feeding is the real issue with the mn..seem like this thing was built around the 7.62x54 in all aspects but please have at it..

#4 gun nutty

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Posted 10 January 2007 - 05:37 PM

The MN is designed around the 7.62X54 in every way.

A real strong candiate is the 405 Win. Rim (.540 vs .563) and overall length are close (405 is just a bit longer). I suspect that it won't feed from the magazine though.

The biggest problem that I see is the feed ramp. Mausers and most other actions have the feed ramp forward of the magazine. Not so with the MN, as it's situated midway in the magazine opening. Opening the magazine for larger cartridges (45-70, 405, etc.) eliminates the feed ramp partially if not entirely.

The long ejector holds the rear the case (the rim) down and the feed ramp centers and guides the point of the cartridge into the chamber. Insert a 7.62X54 round into the magazine and push the bolt forward, looking carefully at where the case hits the ramp. Look also at the way the rear of the case is held-down by the ejector. Smaller diameter rims just don't seem to position the case right at the rear. The actual case head diameter seems irrelevant. It's the rim and cartridge body taper doing all of the work.

I'm guessing that the best candidates for this action are rounds based-on the original Russian case, or cases with a rim diameter very close. 30/40 Krag or 303 British might work well also. 30-30, 44 Mag, 444 Marlin rattle around too much. Looking at my magazine, I think a .32 caliber case would be about max without the front of the magazine (cartridge neck area).

Getting back to to the .405 Win, I think it might make a good donor case for a 7mm, 6.5mm, or .257 wildcat. The case head diameter is .462 (vs the .470 of the 7x57). Using a 7x57 reamer and running it in short to the .462 diameter point would allow using a standard 7x57 reamer. The depth is easy to calculate via a CAD system or a bit of trig. Standard dies could have their bases ground off by the shorted amount. Other than grinding the dies, there would be no additional cost. A good selection of cartridges, or rather their respective reamers and dies, would be available; .244 Rem, .257 Roberts, 6.5X57, 7X57, and 8X57.

#5 sonic1

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Posted 10 January 2007 - 06:50 PM

a barrel for a .405 is not easy to come by...not like a .458 barrel for a 45/70 ..midway does show one in stock for a .405 at $123.00

#6 gun nutty

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Posted 10 January 2007 - 09:17 PM

Douglas offers .411 barrels and specifically lists the .405 as a chambering option; they will long (finish) chamber:

http://www.benchrest...hamberings.html

The Douglas barrel is 1.2" in the chamber area, which will work well with the MN (1.225"). I think most barrels are about 1.2, but some might run 1.25", which would just plain suck.


#7 gun nutty

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Posted 11 January 2007 - 12:44 PM

Now this is interesting...

1. The 6.5X55 Cartridge fits the MN magazine, "oh-so-sweetly". My immediate thought was "if it only had a rim..."

2. The base-to-shoulder length of the 6.5X55 is just 0.023" shorter than the 7X57. I don't have a 7X57 case to try in the MN to verify fit.

3. Midway sells 7X57 Rimmed Norma brass for $20/20.

4. The 7X57 Rimmed rim diameter is .532, according to my reference.

If the 7X57 Mauser fits in the magazine, the 7X57 Rimmed case is an great candidate. The 7x57 is the parent for the .257 Roberts .244 Rem and 6.5X57. If feeding is good, this could open the MN to a number of cartridges. I'm not sure that the MN ejector will hold down the .532 rim though...

Might be a winner. Thoughts?

#8 Racepres

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Posted 11 January 2007 - 03:17 PM

Bring a Large Fan of the 7X57, as well as addicted, to Wildcats... I can see tremendous possibilities!! Keep us posted. MV




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