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

[Ontario Hunter]

I fitted the P14 magazine spring this evening, it curtainly helps pushing the cartridges up. But I think it is obvious that I need to move the shoulder point forward in both the feed rails and magazine box.
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Is it feeding poorly? What are the symptoms? Is the bullet hitting the loading ramp? Cartridges not staying in the magazine?

 

[BlueFlyer]

Is it feeding poorly? What are the symptoms?

I was in a bit of a rush last night, and I really need to spend some time to analyse what is going on. Most are feeding perfectly, but I had a couple where the bolt went over the rim. The cartridges are bottoming on the shoulder and the rim tends to float around.
If I extend the shoulder rebate forward I am hoping it eases the pressure on the shoulder and reduces the freedom of the rim to float around.
Any thoughts and experience will be greatly appreciated.

 

[Ontario Hunter]

I was in a bit of a rush last night, and I really need to spend some time to analyse what is going on. Most are feeding perfectly, but I had a couple where the bolt went over the rim. The cartridges are bottoming on the shoulder and the rim tends to float around.
If I extend the shoulder rebate forward I am hoping it eases the pressure on the shoulder and reduces the freedom of the rim to float around.
Any thoughts and experience will be greatly appreciated.

No experience but I will offer some thoughts. This was exactly the issue encountered by Westley Richards' designer Taylor when he developed the first rebated rim cartridge, 425WR. He "fixed" it by making the magazine box narrow single stack and extending below the stock. Others have remedied it in conventional staggered stack actions by substantially beefing up the follower spring. Seems your Enfield spring, though stouter, still does not have enough poop. I would explore beefing the spring up even more. Start messing with the rails and you run the risk of cartridges jumping them prematurely. I'm wondering if the tilted design of Siamese magazine might be the problem. Magazine leaf springs are typically designed for horizontal boxes. Try this: insert a wedge between spring and end of your follower. That may add enough extra spring tension and compensate for drop at end of floorplate.

If that helps, you know where the problem lies. Perhaps consider ordering a spring from Winchester designed specifically for WSM rebated rim.

 

[BlueFlyer]

insert a wedge between spring and end of your follower. That may add enough extra spring tension and compensate for drop at end of floorplate

I like this idea - easy to try and reversible.

 

[Rule 303]

Good idea Ontario Hunter but not for Australia. Trying to get anything out of Winchester is a drama that takes forever. Better off trying a Ruger mag spring for their WSM rifles. Though the mag springs for WSM rifles are for short actions, not sure how they will work in a standard length action. I have not checked this so for all I know nowadays the make one mag spring for both actions lengths to save money.

 

[BlueFlyer]

I am going to keep trying to get this to work with the original magazine, but the final get out of gaol is a single stack box magazine. That was how I finally got my P14 in 9.3X64Brenneke to be 100% reliable.

 

[Ontario Hunter]

Good idea Ontario Hunter but not for Australia. Trying to get anything out of Winchester is a drama that takes forever. Better off trying a Ruger mag spring for their WSM rifles. Though the mag springs for WSM rifles are for short actions, not sure how they will work in a standard length action. I have not checked this so for all I know nowadays the make one mag spring for both actions lengths to save money.

I thought the Ruger "short" action is the same or almost the same "length" as a standard Mauser action. Both, as I understand it, are for 30-06 or 8mm length cartridges or shorter. The idea of WSM cartridge was to make a magnum cartridge work in a standard length action without carving into feeding ramps or extending magazines. Open the bolt face, modify the feeding rails slightly, and away ya go. As I understand it, the follower spring also had to be beefed up. And I'm sure the followers had to be changed. The idea was the same as Taylor's but for different reasons. Westley Richards couldn't get access to magnum length Mauser actions because Rigby had production locked up. Winchester wanted to build a rebated magnum on a short/standard action to cut costs.

If loading your last round is problematic, you may need to change the follower. But only if this is SOLELY the problem. Making the upright fence in the follower narrower on the cartridge contact side will allow more of the rim to be in contact with bolt face. With the fence face thinned, the cartridge moves further towards the center of the box which allows it to be pushed further away from feeding rails which allows the rim to be raised.

Look at my follower above. You can see where I carved into it at the point where I wanted the final 404 cartridge in magazine to slip sideways out from under feeding rail so follower spring can push it the rest of the way under the extractor and fully on the bolt face. The rails had both already been perfectly modified with three and then two dummy cartridges in magazine. Mistake many trying to build magnums on standard Mausers make is modifying the rail for last cartridge first. Then they discover too much metal has been removed from that side when box is fully loaded. Cartridges jump the rail before the bolt face can catch them. Crap! Putting metal back on the rails is an exercise in futility for most of us mortals. It would be MUCH easier putting metal back on a follower and reshaping it than feeding rail.

 

[BlueFlyer]

I need to get disciplined and step this out with changing 1 variable at a time to really understand the feed issues. At the moment the dummy cartridges have the projectiles seated at different depths.
No cartridges are jumping out.
Last cartridge is feeding fine, =right side rail.
First cartridge is feeding fine, = right side rail
I think all the feed issues have related to the left side feedrail.

But I need to confirm this.

 

[Rule 303]

I thought the Ruger "short" action is the same or almost the same "length" as a standard Mauser action. Both, as I understand it, are for 30-06 or 8mm length cartridges or shorter. The idea of WSM cartridge was to make a magnum cartridge work in a standard length action without carving into feeding ramps or extending magazines. Open the bolt face, modify the feeding rails slightly, and away ya go. As I understand it, the follower spring also had to be beefed up. And I'm sure the followers had to be changed. The idea was the same as Taylor's but for different reasons. Westley Richards couldn't get access to magnum length Mauser actions because Rigby had production locked up. Winchester wanted to build a rebated magnum on a short/standard action to cut costs.

I am not sure what you are saying. The action lengths are, Short, Standard/Long and Magnum. Short actions are for the 308 and similar length rounds. The WSM were made to fit and cycle through Short Actions. The Winchester M70 has the longest magazine of the short actions and as far as I can tell is still shorter than a Standard Magazine as in the Mauser 98. Yes some have made actions specifically for 223 length rounds or shortened their magazines in a Short Action to hold the shorter rounds.

The Rugger Extractors are a shorter carbon copy of the M17 extractor even on their long actions, don't know about the Rugger Magnum Actions.

 

[Rule 303]

Blue Flyer I am surprised you could not modify a P14 or M17 magazine to reliably feed 9.3X64 in a double stack configuration as they sides can be taken off them and the ends narrowed or widened as needs be. May have needed to work the feed rails as the P14, as you know, was set up to feed the 303 cartridge. 303 Rim Dia .530" 9.3X64 Rim Dia .492" with a Base Dia of .504"

Please remember I am an out right hack when it comes to these things so I could be barking up the wrong tree.

 

[BlueFlyer]

I am surprised you could not modify a P14 or M17 magazine to reliably feed 9.3X64 in a double stack configuration

The M17 will feed the 9.3X64 no problem, as it is set up to feed the 30/06. My M17 is chambered in 280AI, no feed issues for it.
The P14 is a totally different beast in the feed rails. It has an extra wide cutout for the rim and the Brenneke base diameter is much smaller than the rim of the 303, the Brenneke is also a rebated rim just to make it more difficult. I made numerous magazine boxes and extended the sides up into the rim rebates. I got it close to working but never 100%. I am very reluctant to try and add material to the rails by welding. My worry is warping the action, as the molten weld material cools it shrinks significantly, and creates localised tension and stress which may cause the action to warp.
The single stack Schultz & Larsen magazine is clamped into location by the hinged floor plate and is 100% reliable and zero risk as the feed rails are no longer relivant to feeding the cartridge. As per the Wesley Richards solution to the problem.
The Siamese Mauser is much closer with the WSM cartridge unmodified than I was with P14 and Brenneke, so I am still hopeful it will feed without going to a single stack.

 

[Ontario Hunter]

I am not sure what you are saying. The action lengths are, Short, Standard/Long and Magnum. Short actions are for the 308 and similar length rounds. The WSM were made to fit and cycle through Short Actions. The Winchester M70 has the longest magazine of the short actions and as far as I can tell is still shorter than a Standard Magazine as in the Mauser 98. Yes some have made actions specifically for 223 length rounds or shortened their magazines in a Short Action to hold the shorter rounds.

The Rugger Extractors are a shorter carbon copy of the M17 extractor even on their long actions, don't know about the Rugger Magnum Actions.

You are correct.

 

[BlueFlyer]

Had some time this afternoon to try and sort out the feed issues. I resized 3 fresh cartridges and then seated the projectiles to an overall length of 74.5mm. Spring used was P14.
The first and 3rd cartridge (right feedrail) would feed fine the second cartridge (left feedrail) the base consistently slip under the bolt face. The base was slipping further to the left as the cartridge was fed forward. This indicated to me that I need to try an control the base of the cartridge from moving left. I cut out a small plate of 0.8mm material and just wedged it in there to see if it worked.
The first trial and all 3 cartridges fed and ejected without any problems. Ultimately I will soulder and rivet the plate in if in the long term it is totally reliable. For now I have just glued it in with 24hr epoxy to perform live fire trials.

 

[Ontario Hunter]

Excellent. So this sleeve meets the feed rail or does it extend above it?

Edit: I see. It must extend beyond the feed rail if the same height as backing plate on end of the box. The solution for rebated rim feeding problem faced by Taylor of Westley Richards would seem to have been make a box and rails that sqeezes together at the top back end. Not that difficult to satisfactorily reshape the rails but making an alternating stacked mag box that significantly tapered in at the top perhaps required more complex machining. So he opted for single stack longer (more unsightly) design.

Your solution was a cautious approach. Very smart. I think many guys would have tried messing with cutting away on the right rails/receiver to move the alignment in that direction. But difficult to put metal back if it doesn't work. Adding that shim was something that could be easily reversed.

 

[BlueFlyer]

No work on the Siamese Mauser today. I have open sights arriving next week and I have also ordered a walnut semi finished machined stock from Hatchers, they are the only source I could find that will supply Siamese Mauser stocks. I would have preferred a synthetic stock but I could not find anything available. The screw spacing is shorter than the other "short" K98 actions like the Yugo.
I did make a stand for the bullet swaging press that I have recently built. The Rockchucker was OK forming the jackets out of 1/2" copper tube, but the extraction system was the weak point.