My local 'smith tells me that at one time someone was making/selling prechambered and threaded barrels in 45/70 for the Siamese Mauser action. Anybody out there know if there was or is such an item? Anybody happen to have one that needs a home? Thanks.

Just a fair warning about building a 45-70 siamese. Often they only held 2 cartridges down in the magazine, to the disappointment of the owner.

For the same cost you can build a vz24 model 98 mauser into a 458 winchester magnum. It will fit 3 down easily. And you can load it down to a 45-70 if you want.

$0.02

Craigster,

Try E.R. Shaw, http://www.ershawbarrels.com. (Be sure to specify 'Siamese Mauser' not '98 Mauser')

I sent my Siamese Mauser to them 10 years ago. I had them to the installation and perform work like opening the bolt face and machining the front of the receiver as well.

I'm going off memory, but I think I could smash 3 rounds into the mag, but the follower is a jimmied non-original unit. I'll go home today and refresh my memory on capacity and see how it feeds with factory ammo.

As I remember,Numrich Arms was the driving force behind the Siamese Mauser to 45/70 conversion kits. I've built one of these and as others can tell you, if your not in it for the novelty, consider other options. Feeding and ejection problems are the rule rather than the exception and while it can be made to work. It will be a giant pain!Why bother! You can't make a 458 win mag out of a 45/70 even in a Siamese Mauser action. Your way better off with a std Mauser and stay away from rimmed cases.-Rob

30/40 Krag works better in the Siamese action. Easy to duplicate .308 win ballistics in the M98 action.

E.R. Shaw still offers them.

Thanks for all the info, guys. Yeah Rob, this is somewhat of a novelty/nostalgia project, some guys never learn. Another round that looks damn close to perfect is the 7.62x54R Rooskie. Yeah, that's it, a German designed rifle, made in Japan, sold and used in old Siam, and chambered for a Russian cartridge. Now that would be novel! Like my signature says, there's a ine line between..., well you kow the rest.

I took my .45/70 Siamese out this past weekend. I discovered it will hold three in the mag, and a 4th in the chamber. The trick was to press the 4th halfway down into the magazine to chamber the round, making sure the rim was behind the extractor (a two hand operation). Feeding seemed a little sticky with Remington 405 grain flat-points. Sometimes a little back-and-forth action on the bolt was needed to get the rounds up the front of the magazine and feed ramp and into the chamber. No problems with extraction. Ejection was mediocre. About 75% of the empties would clear, but the rest would hit off the ejector and settle back into the action. The rim of the last round would consistently hang up on the follower and stick out at a 45 degree angle, still held by the extractor. I've got no details on accuracy with the Shaw barrel because, well, I recycled the scope onto something else.
I'd have to agree with the other posters that this is a novelty, and the money is best spent elsewhere, but best of luck on treading the fine line...