Converting a savage LA (7mag) to feed 7RUM cartridges from the magazine?

[Max Heat]

Since the (staggered) magazine WILL NOT fit the .35" longer RUM cartridges, I know it would have to be changed to one that is longer. The problem that I am seeing, is that the bottom part of the action where the mag attaches would have to be cut/milled, in order to accept a longer mag. I am neither a smith, nor a machinist, so I don't have a mill or any type of machine that could do that. What are my options? (aside from the "take it to someone that does" answer)

 

[KRP]

Do you have a set of files?

 

[KRP]

Do you have a set of files? Do it the old fashion way.

 

[geargrinder]

Go nuts with a dremel.

Take the back end of the mag opening flush to the lip of the lip of the bolt head.

Take the front of the mag opening so that it is flush with the mag box. Go easy here, your removing material right behind the lower abutment.

Take a mag box and slot the front end so the bullets can stick out. Make a floor for it to hold in the follower and spring. Then epoxy the mag box assembly into the stock.

You should be able to run about a 3.9" or so COAL.

I've done it, but I don't think it's worth it. Single shot is so much easier, and no permanent mods to the action.

 

[Max Heat]

I do have a dremel, and lots of files, also. But I thought I would have to start out by obtaining a longer mag box, and removing enough metal, from both front and rear of the action, to get it to fit in. I think slots also have to be cut, both front and rear, that lips on the box need to slide into. MY CUV stock should be able to serve as the floor, for the spring & follower, I would think.

I would prefer to install a box (and follower too, I guess) that IS the proper size for the rounds, rather than slot out the front of my existing one. I would only have to modify the action to fit the box then. Any ideas on where the correctly sized mag box can be purchased?

Oh, 1 more question: The "lower abutment" isn't what the right-side locking lug locks down into when the bolt is closed, is it? I would be VERY hesitant to remove ANY metal from THAT area, if that is in fact, the case.

 

[can1010]

when i did my 338 edge i took two mag boxes and spliced them together with jb weld epoxy then extended the follower. it works great but takes a lot of time. you will still have to open up the action

 

[geargrinder]

There is no box long enough for the RUM's and long seated bullets. You either need to make one or modify one.

You have to remove material from the front of the mag opening (lower abutment) or the bullets from your longer magazine will hang up on the bottom of the action.

You're asking the savage action to do more than it was designed to. The Savage is not well suited for the long seated RUMs except as a single shot.

 

[KRP]

With a shorter front baffle(RUM, pushfeed WSM, modified original) you can get more length without modifying the front of the mag opening.

 

[geargrinder]

True, but that only works if you are using the front of an unmodified stagger feed magazine.

It won't work if you use a centerfeed magazine or slot the front of a stagger feed magazine.

You'll also have to remove more material very close to the rear action screw.

The Savage action just does not have much room to work with between the action screws.

 

[can1010]

i didnt remove as much as people think. started with 375 h-h with opening of 3.775 . moved front of box flush with feed ramp and back flush with bolt face now have 3.925. moved bolt stop back slightly to get .020 behind cartridge. total romoved from back .055. gun has same screw spacing 5.062 . now i know 7mm opening is smaller and he will have to remove more but factory already makes ultra mags. i dont think he will be weakining it in any way

 

[Max Heat]

Actually, what I would consider to be the optimal approach, would be to exactly duplicate the savage factory 7RUM setup. Would a mag box for one of those work?

But for some reason, I don't think that the stagger-fed, non-accutrigger 110 model like the one I have was even available from the factory in 7RUM, or was it? Plus, I was under the impression that the models that DID come in 7RUM had a beefier (larger OD) action. I just measured mine, and it is 1.350. I'm not sure what size the larger one is, but it would make sense that the RUM WOULD have used it. All I know, is something I heard about savage being the only manufacturer that went to a larger size. Is there truth to any of this?

If it is true that the factory 7RUM savage actions ARE beefier than the 7RM ones, I won't even consider doing ANYTHING to MY 7RM action that is going to be fitted with a 7RUM barrel. I would just have to accept single-shot mode.

 

[can1010]

max heat. the 375 i am using is the same as yours. savage made large and small shank barrels in ultra mag. all three of mine have same 1.350 action. just barrel shank is different. dont know if an ultra mag box is available nobody lists one maybe try calling savage. i spliced two together 338 edge 3.830 fits and functions perfectly. good luck on your project

 

[Max Heat]

OK, so you are saying that RM barrels are small shank, but RUM could be small OR large shank?

Now I'm concerned about the possibility that the RUM barrel that I ordered may not be the right size to fit my RM action. Would this be a legitimate concern, or will the new RUM barrel be the small-shank version by default?

I may consider leaving it single-shot. I'll have to try it out first, before I make a final decision on it, I suppose.

 

[can1010]

older rum is small shank. newer ones are large shank. call your barrel maker and double check you need small from what you described. 1.055 inch shank