Siamese Mauser 45-70 Super Nitro

[Ahall]

I agree the stamping looks like it was done with hand stamps, so who knows what the maker intended, or what they fed it. My money would be on hot hand loaded 45/70s, but thats a guess.

There is a lot of data on the old 45/70 and hot loads that take advantage of the case capacity and modern powders. I don't recall any of them mentioning Siamese Mausers as an approved action for the hotter loads.

Do your homework.

 

[Pulp]

AFIK, only two rifles are strong enough for max .45-70 loads, and they are the Siamese Mauser and the Ruger #1. There may be others, but those are the only two listed in my reload manual.
And in spite of what some people say, I’ve never found a load recipe that comes close to equaling .458WinMag.

 

[aarondhgraham]

Here is a Wikipedia article on the Siamese Mauser,,,
It doesn't say a thing about the re-barreled imports though.

Aarond

.

 

[TeamTomlyn]

Looking at the stamping, it appears the "super nitro" to be done by hand and not machined. The person stamping was very good but the lettering is not consistent which makes me think it was indeed a one-off barrel by a gun maker.
It will be really interesting to see what you find in your measurements of the chamber, etc.

My thoughts too, the letters are just a little off the line. Plus the barrel and action match perfectly; so they were at least blued at the same time.

 

[osu007]

My thoughts too, the letters are just a little off the line. Plus the barrel and action match perfectly; so they were at least blued at the same time.

I don’t know about the one in question, however I had a “Navy Arms” 45-70 that had been converted from a Siamese Mauser. I never tried to hot load for it as it shot lever evolution more accurately. Super accurate. It shot accurate enough for a head shot on a spike at about 70 yds and 45-70 lever evolution does a number on a deer’s noggin. There were also 45-70 converted from old enfields. Good guns.

 

[Jack Shootza 50]

Here’s a good one for the brain trust!

I just got handed this gorgeous Siamese Mauser chambered in “45-70 Super Nitro”

View attachment 314299

Contracted out from Germany’s 98K design; the king of Siam contracted with Japan to make 40K of these rifles between 1903 and 1908.
During production the Japanese arsenal added their own influence to the 98k design. Which from what I’ve read makes it one of the stronger Mauser actions but also makes its parts unique from other mausers.
In the 1960s these became surplus rifles and began showing up in the US. Due to the parent cartridges requiring a large bolt face it was popular to rebarrwl these for the 45-70.

Okay, cool history lesson, right? Well then this happened
View attachment 314300
Now let me save you a google search, it won’t be that easy. I have yet to find a whisper of a 45-70 Super Nitro anywhere on the interwebs.

either this has to be a 1 time wildcat elephant rifle with some kind of monster parent case.

Maybe he saw Quigley and wanted to get one up on his 45-120 by making his a Super Nitro

My guess is since the 45-70 cartridge has been around since black powder and you’ve got to be very cautious of your pressure levels. This being the latest and greatest in barrel technology of its time could handle all the CUPs/pressures and the old timer denoted that as a Super Nitro.

So before I slug the barrel and make a chamber casting what do ya think it is? Ever seen such a beast before?

I've built six Siamese rifles over the years, one in 45/70, one in 450 Alaskan, two in 50 Alaskan and two in 375/348 Improved, I still have one 50 AK and both 375's, I've never heard of the 45/70 being called a Super Nitro, I think some gun smith or customer got over zealous with the letter stamps

 

[Jack Shootza 50]

I've built six Siamese rifles over the years, one in 45/70, one in 450 Alaskan, two in 50 Alaskan and two in 375/348 Improved, I still have one 50 AK and both 375's, I've never heard of the 45/70 being called a Super Nitro, I think some gun smith or customer got over zealous with the letter stamps

Another tid-bit about the history of this action is the king of Siam requested that the guns be built by the Japanese because they had the best steel in the world at that time so the actions are quite strong and can handle modern day pressures, although the tenon is a smaller thread diameter than a 98 and shorter too. I have shot loads in my 375 that are at 55-60,000 psi with no ill effects although I generally stay below 50K just because it's easier on the shoulder. For anyone interested in the 375/348 the case capacity is almost identical to the 376 Steyr and that is what load data I used to compare with.

 

[WoodsCraft]

You can load a 45/70 within a hundred or so feet of a 458 win mag in a Siamese mauser or a Ruger No 1 . You probably won’t enjoy it much though unless you just like recoil. As someone who has shot Trapdoor rifles for years I can say factually most people don’t like full power trapdoor loads and those pressures are sedate compared to full power lever gun loads which a milder in comparison to loads which are shot in a bolt gun

 

[TerryP]

Never heard of such a beast, hope you find out it's something crazy cool and not just their way of saying it's a .45-70 built to handle smokeless loads.

This

 

[Rez Exelon]

You can load a 45/70 within a hundred or so feet of a 458 win mag in a Siamese mauser or a Ruger No 1 . You probably won’t enjoy it much though unless you just like recoil. As someone who has shot Trapdoor rifles for years I can say factually most people don’t like full power trapdoor loads and those pressures are sedate compared to full power lever gun loads which a milder in comparison to loads which are shot in a bolt gun

Yeah.... my trappy is probably one of the hardest hitting things in my lineup....and has a suuuuuper light trigger for that big banger.