416WSM on Siamese Mauser & 416/348Ackley Improved on Martini

[Ontario Hunter]

Well, if it feeds and extracts and ejects cartridges that are spec overall length, then no need to change the rails. Is it cycling smoothly? The 416 Rem Mag bottom metal I bought for my 404J build was also narrower in the shoulder than Paul Mauser's cosine 30 degree formula. Figured I could widen it enough but didn't need to. It works fine. In fact, it probably works better. With the shoulders squeezed a bit, the bullets are pointed more towards center of loading ramp. Your cartridge rim should be up and into the claw well before it is to shoulder area of rails.

Good work. I am surprised you are cycling rebated rim WSM this easily.
Bolt was not overheated or you would not be able to reassemble the shroud. Whoever put the bolt handle on mine was not so careful. I had to true up things when changing to new safety.

 

[Spearhead]

Nice lathe work.

 

[BlueFlyer]

The Siamese Mauser magazine spring is anaemic. The P14 & M17 have much more force and I will try to swap one into the Siamese Mauser.

 

[Ontario Hunter]

Okay, looking at your photos the mag box is single stack that transitions to staggered at the receiver. I agree you may need to modify the rails at shoulder otherwise it looks like bullet tip will be hitting chamber on opposite side as bolt closes. So tuning the rails, follow my instructions earlier. Put three dummy cartridges in the box and tune the contact rail. Then two in the box and tune the other rail, then with just one in magazine tune the follower only, reshaping it as needed. I used grinding wheel on Dremel tool. A little bit taken off then reassemble and check. It took me almost two days to tune the rails and ramp but I had a lot more metal to remove. Be patient.

Sorry but the site is giving me fits today. Stop and start. Getting hung up all the time.

 

[mauserhunter]

Looking good, mag fit is pretty close. Now I'm thinking a 375wsm would be cool or even use the ruger case.

 

[Ontario Hunter]

Okay, looking at your photos the mag box is single stack that transitions to staggered at the receiver. I agree you may need to modify the rails and receiver at shoulder area otherwise it looks like bullet tip will be hitting chamber on opposite side as bolt closes. So tuning the rails, follow my instructions earlier. Put three dummy cartridges in the box and tune the contact rail. Then two in the box and tune the other rail, then with just one in magazine tune the follower only, reshaping it as needed. I used Dremel tool with grinding wheel. Took me two days to modify rails and ramp but I had a lot more metal to remove. Be patient. Remove a bit, reassemble, try cycling, start over, etc. Very slow work. Do NOT want to remove too much from rails.

Sorry but the site is giving me fits today. Stop and start. Getting hung up all the time.

Is the box stamped metal?

 

[Ontario Hunter]

Sorry for double post. Site is all over the place trying to post. Something is going on.

 

[BlueFlyer]

I missed posting the photo of the tool & cutter grinder setup.

 

[mauserhunter]

I really need to buy a tig welder I've got a few bolts that need welding, one day I'll see if the old clapped out south bend can make some bolt stubs to.

 

[BlueFlyer]

Is the box stamped metal?

The box is milled, single piece.

 

[Ontario Hunter]

This has been an intriguing thread. I have a buddy who's got a couple of those Siamese actions for donors. He is convinced 45-70 is all he can build with them. I would not have thought the bolt face issue could be overcome.

 

[Rule 303]

If it's an 8mm rimmed version of the Siamese Mauser then it would require changing a 16mm bolt face and extractor into a 13.6mm WSM ... if that's even possible. But apparently some Siamese Mausers were made in 30-06 and even 30 carbine (ugh!). If one of those, then it would be a manageable build to open the bolt face and extractor. But can they be reduced in diameter? And you're probably correct about feed lips. The feeding rails for a fat rimmed single stack cartridge would have to be widened for a narrower cartridge = adding metal. Would seem to be a challenge.

Yes this can now be down with Laser Welding. Can add as little 1 thou I am told.

 

[Grumpy gumpy]

Re the bolt face, Laser welding or sleaving the recess will both work. Whoever does it will need to watch for heat transfer, but most competent welders could do it.
gumpy