8mm mauser-220 Swift conversion

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mattL46

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So I was doing some research and because I'm awfully fond of the swift cartridge I was thinking AFTER I play extensively with the 8mm Mauser ( when and if I can buy ammo/reloading components) I MIGHT want to convert it to the swift. Considering the head Diameter is actually the same and the swift is shorter is there really much I would have to do to the bolt/claw and feed rails etc? thoughts and opinions. Again I doubt I'll ever convert because I really like the 8mm just me thinking.
 
Sounds like a question for the Gunsmithing Forum. Drawing on my knowledge as a "Johnsmith" I know the Swift was marketed based on the 6MM Lee Navy and I wonder how close that is in measurements to the 8MM Mauser.
 
FLG who did a lot of that stuff in the First Wave of surplus Mausers, pre GCA68, said he never bothered with magazine alterations on target and varmint conversions.
Do you need a rapid fire Swift?
 
Sig the head dimensions are the same body taper a bit different. Swift is shorter. I think it would be a pretty minimal conversion myself.
 
That conversion is simple, new barrel and you should be good to go.

FWIW, the 220 Swift has the same rim size as the 8X57, the head size is slightly smaller than the 8X57 head size.
 
Scorch good info. That was my thinking. I was say head and was meaning rim. Head is only about 3 thous. Difference. You don't think the feed rails would need attention? Taper is similar. Body size and diameter is similar.
 
No, the feed rails won't need any work. That is a very straightforward conversion. New barrel, maybe some extractor tweaking, but pretty much plug and play. Easier than 22-250.
 
Not trying to hijack the thread but this has got me really thinking as well... I have a sporterized 8mm Mauser, and I also have a Green Mountain barrel chambered .220 swift, threaded for a Remington 700. How close are the threads between the two? Could I have the Barrel re-threaded to fit the Mauser?
 
By all means Steven. You would have to know the thread pitch and diameter of both which I don't before hand.
 
I dont know. Havent had the barrel off of it. Its a '44 model German 98 made by Gustloff Werke in Weimar, Germany. Dont know if that would tell you anytyhing for sure about the barrel thread dimensions. I'll have to do some research. Thanks for giving me the idea
 
Yeah there is ALOT to know. Shank length. Thread pitch and diameter. I lightly researched it and its way over my head. Ha ha. Very interesting though.
 
Scorch anyway you can send me in the right direction for said barell? Reputable quality barells?
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McGowen barrels. Best value in a premium barrel that I know of.
I have a sporterized 8mm Mauser, and I also have a Green Mountain barrel chambered .220 swift, threaded for a Remington 700. How close are the threads between the two? Could I have the Barrel re-threaded to fit the Mauser?
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You will need to have the barrel rethreaded. If you have a good machinist, you won't have to lose any length, either. Rem700 threads are 1.061"-16 tpi IIRC, Mauser threads are .990"- 12 tpi IIRC, so you could just recut the shank and rethread, then headspace it. You will have to cut the chamber a little deeper because you will lose about 5/32" at the rear of the barrel due to the bolt head recess on the Rem700. Anyway, very doable.
Does the Mauser have an interrupted thread?
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Very, very few factory commercial Mauser 98s have interrupted threads. Probably no military 98s. Europeans have always liked switch-barrel guns, but they are not terribly fond of interrupted threads for some reason. I have seen two commercial Mausers with interrupted threads, but I am unsure whether these were done in the USA or made abroad and then imported. Griffin & Howe used to convert many rifles to takedown by making them into interrupted thread switch-barrels. The European switch-barrel Mauser 98s I have seen used a dovetailed affair to hold the barrels, and may not have held up to extensive firing.
 
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I wondered how an interrupted thread on a usually high powered rifle would hold up. I'm not sure I would want the convenience of a takedown/switch barrel on that type of rifle.
 
Here's an answer from someone who built his own Swift from a M98 Mauser action. There's a big diff in the case shape with the Swift being much more tapered. Feeding is iffy depending on how worn the original action was. In addition, care must be taken when loading the magazine so that the rim of each round loaded lies in front of the rim of the previous case. There may also be problems when the round pops out of the magazine w/o being caught by the extractor and/or feeds nose high with the bullet catching the face of the barrel shank. I tried some of the aftermarket single stack detachable mags which helped considerably.
Remington barrels can be rethreaded to fit SMALL ring Mausers but not large rings unless you wish to cut the original Remington barrel shank off and recut the shank as well as the threads. I had several Turkish 98 actions(physical outside dimensions like a large ring but with small ring barrel threads) built using new takeoff Remington barrels.
 
Thanks for the input mobuck...hopefully I don't have the same issues. These are just thoughts at the time. I'm going to play with the 8mm for awhile first.
 
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