[cbujol]

I’ve got a mas 36 converted to .308, the ones done by Century Arms. I’m trying to make it more practical and really correct Century’s mistakes. It’s a fun gun to take to the range so I’m pretty satisfied with it but I’d like to take it hunting every now and then. I can fix most of the issues no problem but its biggest issue is how tough it is to feed.

It’s a 2 step process of getting the nose of the round into the chamber, pausing, then actually chambering the round and closing the bolt. This only works with FMJ too. It’s almost impossible to feed soft tips or hollow points from the magazine. I’m sure polymer tips would be a bit better but I want to try to fix the issue entirely.

I was thinking that making the barrel ramp a bit shallower would at least help. It’s definitely not worth sinking the money into it that a trip to the gunsmith would cost so I’d do the work myself. I have no real way of taking the barrel off so I would have to do the work through the receiver. I’ve got a dremel with a flex shaft and all the bits I could ever use to do most of the work with. I’m not a professional but I’m fairly experienced and have done some similar work.

Is there anything I should consider while doing this? Any dimensions that I could work with? Any advice would be helpful.

 

[JBelk]

What is a mas36 and what was it before conversion?

 

[shreck]

I just had a google on the mas 36 ,cool looking rifle ,hybred french battle riffle ,looks like a good scrub /range gun.
I quiet like its rugedness.

 

[Bong Son Buck]

You state that you think the feed angle should be lessened, but to do that you would remove metal? I don't know much about the MAS, other than Hornady's caution to make SURE the primers are set BELOW flush, or it will slam-fire! I think you'd be better served if you bought a 7.5X54 replacement barrel (I think they're available from SARCO) and had it installed. That way, the feeding geometry should be right, and it should feed properly. The ammo is probably going to be hard to find, but not impossible. Try Graf's. The ballistics are about the same as 308 Winchester. I HAVE heard some nasty stories about those conversions, and not knowing how true they are, I'd err on the side of caution here. And welcome to the discussion!

 

[rojkoh]

I’ve got a mas 36 converted to .308, the ones done by Century Arms. I’m trying to make it more practical and really correct Century’s mistakes. It’s a fun gun to take to the range so I’m pretty satisfied with it but I’d like to take it hunting every now and then. I can fix most of the issues no problem but its biggest issue is how tough it is to feed.

It’s a 2 step process of getting the nose of the round into the chamber, pausing, then actually chambering the round and closing the bolt. This only works with FMJ too. It’s almost impossible to feed soft tips or hollow points from the magazine. I’m sure polymer tips would be a bit better but I want to try to fix the issue entirely.

I was thinking that making the barrel ramp a bit shallower would at least help. It’s definitely not worth sinking the money into it that a trip to the gunsmith would cost so I’d do the work myself. I have no real way of taking the barrel off so I would have to do the work through the receiver. I’ve got a dremel with a flex shaft and all the bits I could ever use to do most of the work with. I’m not a professional but I’m fairly experienced and have done some similar work.

Is there anything I should consider while doing this? Any dimensions that I could work with? Any advice would be helpful.

Can you take a picture looking down into the action, showing the feed ramp and magazine follower?

 

[shreck]

My rossie has a bit of a curve worked into the bottom of the barrel face ,would doing that be dangerouse.

 

[cbujol]

Sorry for the late response. Had computer trouble, got busy, and nearly forgot about this post. I've got the bolt action mas 36 so the slam fire isn't an issue. I'd really like to keep it as a .308 due to all the variety. Below is a picture of the ramps.

When the rounds encounter the ramps it either loads fine, the nose angles up pretty drastically and it catches on the follower, and on occasion rounds on the right will go nose first into the flat under the ramp.

 

[rojkoh]

Sorry for the late response. Had computer trouble, got busy, and nearly forgot about this post. I've got the bolt action mas 36 so the slam fire isn't an issue. I'd really like to keep it as a .308 due to all the variety. Below is a picture of the ramps.

When the rounds encounter the ramps it either loads fine, the nose angles up pretty drastically and it catches on the follower, and on occasion rounds on the right will go nose first into the flat under the ramp.

Not hard to understand why.... the ramp on the breech end of the barrel is not good, especially to the right. It's just really badly done.

There's a number of ways to improve that either by having the ramps on both sides improved, or you can done one to cover both sides of the feed like I have on a .308 barrel I have screwed on my 03 at the moment. IF you want pictures, let me know.

OR if the company that built this is still around, call them and raise H*LL

 

[cbujol]

I'd love some pics. Single feed ramps seem to be easier to get more reliable.

Century is kind of known for their crappy production and customer service so i really don't want to deal with them.

I'm thinking that I can grind down the ramps a little bit and solve the issue. That shear cliff on the right needs to go and the left feed ramp needs some work too. It can't get much worse and if I do screw it up I'm willing to get a new barrel.

This is really just something to tinker with and I've made quite a few modifications and have greatly improved the rifle with more to come in the future.

 

[JBelk]

cbujol-- As a gunsmith with a drawer full of feeding 'experiments' gone wrong, I'd advise a VERY careful study of the feeding system used in that rifle with original ammo. Are those 'feeding ramps' in the butt of the barrel or are they clearance cuts for the bullet nose? MANY military, control feed guns are fed from the cartridge SHOULDER, not the bullet. All M-98 Mausers with bowed rails are such rifles. Straight-rail Mausers use the bullet nose. There are many thousands of ruined M-98 actions with 'opened up rails' from a 'smith not knowing the difference in systems before grabbing an abrasive.

Double-stack magazines are a matter of geometry and spring forces. Most Mausers are 45 degree stacks and 47 won't work right and neither will 43 degrees. Your MAS maybe the same, you'll have to figger that out your own self.

 

[MontyF]

Welcome to the shooters forum.

Looking at the pics it appears the feed ramps, especially the left one extends some distance in the chamber. I would certainly be careful making them any deeper since you will be getting into unsupported head territory with a high pressure cartridge.

 

[rojkoh]

I'd love some pics. Single feed ramps seem to be easier to get more reliable.

Century is kind of known for their crappy production and customer service so i really don't want to deal with them.

I'm thinking that I can grind down the ramps a little bit and solve the issue. That shear cliff on the right needs to go and the left feed ramp needs some work too. It can't get much worse and if I do screw it up I'm willing to get a new barrel.

This is really just something to tinker with and I've made quite a few modifications and have greatly improved the rifle with more to come in the future.

Jack's right about the geometry of the magazine feeds, you can get yourself into trouble real fast on something like this, including undercutting the relief and end up with an unsupported/improperly supported case. I'll get to the pics asap, Have to pull 2 or 3 rifles out because I have a number of .308 rifles and I think I still have a 7.62x39 barrel on my SAKO. It was originally for .308

Sorry, I really haven't touched one of those in at least 40 years. Not a real big fan of french firearms.