What Load Level in a Siamese Mauser .45-70?

[Gray Fox]

This Wednesday I'm picking up what photographs show to be a nicely done .45-70 on a Siamese Mauser action. I'm wondering what level of .45-70 load data from the manuals is appropriate. Specifically, can I use data recommended safe in a Ruger #1 or Browning high wall? If not, I'm assuming date for the Marlin 1895 would be safe.
If I can make the photo attachment thing work I'll post some photos once I get it. GF

[KCSO]

You can go all the way from trapdoor to OUCH! The mauser will hold more powder than you will care to shoot. I have used Ruger #1 loads in mine but can't stand the recoil anymore. My 500 grain bullet load was IIRR just 150 fps slower than a 458 Winchester load for my buddy's Elephant rifle. My Siamese conversion was done about 40 years ago by Charles Hanson of Chadron Nebraska.

[Gray Fox]

This one looks to be at least that vintage. I'll know better once I get it in hand. About 15 years ago my B-in-law and I went elk hunting in Utah. We took bolt guns, but each of he took a #1 in .45-70 and I an 1885 in the same caliber in case the area we ended up in was largely dark timber. He work up some loads that probably would have done in an elephant. The second sight-in shot he took he knocked off two caps on his front teeth. I think he toned them down a bit after that. GF

[No_1]

A correctly converted Siamese Mauser will handle the most powerful 45-70 loads including all loads deemed safe for Ruger #1's.

[Larry Gibson]

A correctly converted Siamese Mauser will handle the most powerful 45-70 loads including all loads deemed safe for Ruger #1's.

That it will. I built mine in '73 and refer to it as a 450-400-70 (I have my hallucinations from reading too much Ruark, Taylor, Hunter, Capstick, etc.). I throated mine so the Barnes 400 O SP could be seated to just short of mag length. That gives increased powder capacity and I push it at 2300 fps. Also the 400 gr 458483 at the same 2300 fps. I push a 500 gr C457-500-FN at 2050 fps which is 458 Winchester velocity. Of course it can be loaded down to all the other levels of 45-70 loads. Recoil is punishing off the bench but from standing or sitting you just roll with the punch. BTW; I also pressure test 45-70 loads with my Siamese Mauser and find it possibly takes loads to a 4th level above the 3 levels most manuals list. It does so at psi's the Mauser is capable of handling, whether my shoulder is.........

Larry Gibson

74492744937449474495

[EDG]

I built my Siamese in 1972 from a complete rifle that cost $12.
Most of the Siamese rifles were bult with barrels and stocks that are not heavy enough to absorb the recoil of the top loads possible. There was an early Rifle or Handloader Magazine that had maximum loads a good bit beyond any of todays loading manuals. Basically you could look at a 400 grn loading and that magazine used the same powder charge for a 500 grain bullet. I tried only one 3 shot group like that. I was afraid I would break my stock.
My rifle had the throat cut to exactly match the 400 grn Speer when seated to the second cannelure.

[Uncle Grinch]

Like previous posters say... It will handle more than you probably can.

As for me... I've moved away from those some time ago. Still have half a box of 500 grain Hornady soft points!

[Hiwaygrille]

I am building a 45-70 Siamese Mauser and I am having trouble locating a conversion stock. The posts about Roberts Microsoft stocks scared me away but I don't know of any other makers. Can anyone make a recommendation?

[No_1]

I have 2 Siamese Mauser's. The top is in 30-40 Krag and the bottom is in 45-70. Both are nice, both are strong, both are capable of exceeding standard load data but never do. Last year I foolishly passed on one chambered in 348 Winchester listed on Gunbroker. I am still kicking myself.
http://i129.photobucket.com/albums/p206/no_one_photos/SIAMESE%20MAUSERS/DSC01129.jpg (http://s129.photobucket.com/user/no_one_photos/media/SIAMESE%20MAUSERS/DSC01129.jpg.html)

[Gray Fox]

Boy, do I like the looks of that classic stock on the bottom. GF

[pietro]

That lower rifle's roll-over cheekpiece stock w/Rosewood FE tip & gripcap looks exactly like the takeoff H&R Model 300 issue stock I bought @ a funshow to put on my custom 7x57 1909 Mauser.

My factory H&R stock wore skipline checkering, though.



.

[Andy_P]

That it will. I built mine in '73 and refer to it as a 450-400-70 (I have my hallucinations from reading too much Ruark, Taylor, Hunter, Capstick, etc.). I throated mine so the Barnes 400 O SP could be seated to just short of mag length. That gives increased powder capacity and I push it at 2300 fps. Also the 400 gr 458483 at the same 2300 fps. I push a 500 gr C457-500-FN at 2050 fps which is 458 Winchester velocity. Of course it can be loaded down to all the other levels of 45-70 loads. Recoil is punishing off the bench but from standing or sitting you just roll with the punch. BTW; I also pressure test 45-70 loads with my Siamese Mauser and find it possibly takes loads to a 4th level above the 3 levels most manuals list. It does so at psi's the Mauser is capable of handling, whether my shoulder is.........

Larry Gibson

74495

I'm considering one of these in 45-70 or 45-90. What the max OAL that the mag allows?

[Larry Gibson]

It's a 3" magazine. The OAL of the Barnes load is 2.918". For the full house loads with the Lee C457-500-FN I seat them to and crimp in the top lube groove instead of the crimp groove. The OAL of those is 3". The magazine takes 3 rounds of thus loaded 45-70s.

Larry Gibson

[oger]

It will take more than you can. My shoulder gave up at 1980fps with a Winchester 500 gr fmj.

[JHeath]

A German-proofed Siamese Mauser can handle any load as long as you do not pull both triggers at once. Here is the proper way to load and shoot a Siamese Mauser:

http://www.youtube.com/watch?v=0LXamhyW_aY

[MtGun44]

Both triggers?

Bill

[JHeath]

Both triggers?

Bill

Check the video, and remember this thread is about "Siamese" Mausers.

JH

[Larry Gibson]

Very "punny" there JHeath.....I liked the video and the subtle humor........

Larry Gibson

[CDFingers]

Here's mine, the one I came here to look for loads for.

111455

I have some cast boolits of around 410 grains. I have snagged a few loads through a search. I want to shoot subsonic at 100 yards.

CDFingers

[Bullshop]

In the Pet Loads column in Handloader magazine Ken Waters treated the 45/70 as 4 different cartridges each with a different max load level There was a group 1, group 2, group 3, and super group 3. Group1 was the weakest and the strongest was super group three which included Ruger#1, Browning B-78, and the Siamese Mauser. Possibly the Whithcliff falling block as well as it was popular at the time.

[Uncle Grinch]

Here is my 1969 vintage 45-70. It's parkerized with a Williams receiver sight and sports a utility grade Bishop stock that I primed and painted with black wrinkle finish paint, which has amazingly, held up very well. I also glassed the entire action and barrel, which is 19 inches long.

[Ben]

Mike

I just bet that Siamese Mauser .45-70 (http://castboolits.gunloads.com/showthread.php?204399-What-Load-Level-in-a-Siamese-Mauser-45-70/page2)
is a " MEAN, MEAN, KILLING MACHINE ! "

Ben

[quack1]

Here's mine, built it around 1985. Took it to ER Shaw and got it barreled and chambered and then did everything else myself. It weighs about 9 lbs. The blank came from Fajen. You can go from nice mild loads to ones that will rattle your teeth with no problem.
http://i291.photobucket.com/albums/ll300/1quack1/IMG_0251.jpg

[Bullshop]

I had an interesting exchange with a tech at the Speer lab in Lewiston many years ago. I was using their data book loading their 400gn fn in a Siamese Mauser 45/70. I got to the max listed load of as I recall 62gn Re#7 for about as I recall again about 2100 fps.
At this load level my rifle was still showing plenty of room to keep developing the load up. The tech at the Speer lab told us that the data was not discontinued due to maximum allowable pressure but they cut the data off there simply because he could no longer tolerate the recoil of the test rifle, a Siamese mauser 45/70. I kind off agreed and called it good at 62gn.

[Larry Gibson]

63 gr RL7 under the Barnes 400 gr Original SP runs just under 2300 fps at 62,700 psi measured in my rifle. I consider that a max load. 50 gr H4895 under the Lee C457-500-FN runs 1770 fps at 50,900 psi. 62 gr H4895 under the 400 Speer FPS runs 1978 fps at 36,200 psi. 28 gr AA5744 under a 431 gr cast runs 1420 fps at 27,400 psi.

Larry Gibson

[StrawHat]

I just got the parts to build a second Siamese Mauser in 45-70. Not sure why as I sold the other one back in the 90s. I beat the heck out of my shoulder with that rifle before realizing black powder and soft lead boolits gave come pass through on any of the game I was likely to be hunting. So now I contemplate a second one?!?!

Would really prefer one chambered in 405 WCF but they are not that common.

[Uncle Grinch]

Mike

I just bet that Siamese Mauser .45-70 (http://castboolits.gunloads.com/showthread.php?204399-What-Load-Level-in-a-Siamese-Mauser-45-70/page2)
is a " MEAN, MEAN, KILLING MACHINE ! "

Ben

Ben,

You are so right. I was sitting on a dove stool with a small blind around me and a small buck came walking down the trail towards me. I almost decided to let him pass, but decided at the last moment to go ahead and harvest him for the venison. I shot at 7 yards and the 350 grain PB cast boolit went in the front upper chest and lodged under the skin on his rear quarter. Should have tried a neck or head shot at that range.

The buck staggered back and sat on his rump and then fell over.... very dead!