The widely unknown and forgotten marlin mr-7 - building a mountain rifle in .270 sherman

[codyadams]

Good job! Nice to see things taking shape

Thanks rich!!

Next will be the remington adl mag box modification, my smith said he has several spare adl boxes, springs and followers laying around that he wouldnt mind giving me, so next time I get over to Rock Springs I'm going to grab those and start working on that part.

But things are about to slow down for a minute....in two days we are going in to the hospital, my wife and I are going to get to meet our new baby girl finally after 9 long months ha ha!!

 

[elkaholic]

Well that's even better news! Congratulations and I'll pray that everything goes smoothly there!

 

[Alibiiv]

Well got a little update on this rig!!

My cousin got the stock ordered in, and it turns out it needed a little more fitting than we initially thought, though its nothing a dremel and a router bit/attachment couldn't handle!!
View attachment 126856
View attachment 126849Here, I had to take the inletting about .300" deeper and widen it about .025"

View attachment 126850
Here is the result!!!

View attachment 126851 On the trigger guard area, I had to take it about .030" deeper in the rear, lengthen it behind the rear action screw about .045", and in the front deepen it another .200" or so to allow the trigger guard to fit properly. Also, I had to widen the square notch you see there in the deeper part of the inletting.
View attachment 126853Final result....
View attachment 126854 And a couple rifle pics!!!

View attachment 126855

The action needed some minor inletting, mainly just widening in the bolt area of about .150" or so, and squaring off the inletting under the tang, as it had radiused edges for the Winchester vs the square edges of the Marlin. Bare rifle wieght is still 7.6 lbs, finished with rings, bases, scope, pillars and bedding, it will be right around 9.3-9.5 lbs, so not ultralight, but not too terribly heavy either. I also think it helps when a rifle is balanced, and this one feels pretty good.

We could take about a lb off if we went with an ultralight stock, but we didnt want to dump $500+ into a carbon stock when we were unsure of what inletting would need to be done. Knowing that it's not too bad now (with a dremmel and router attachment), it may be an option for the future, but I think the $150 boyds will be on it for quite a while, my cousin seems to really like it.

This doesn't have anything to do with your build, however I did notice your Dremel tool setup. Just something that I found extremely useful/helpful when using the exact same setup that you have in your first photo here. I Superglued a 3" X 6" piece of clear plexi-glass to the base of the attachment in the photo. I'll use either the router bit that you have in the Dremel now, or will use the long, spiral router bit when I relieve stocks for glass bedding or when relieving stocks for upgrades/modifications. All you have to do is set the depth of the bit and start removing material and it makes all the modifications level with the top or bottom of the stock.

 

[codyadams]

This doesn't have anything to do with your build, however I did notice your Dremel tool setup. Just something that I found extremely useful/helpful when using the exact same setup that you have in your first photo here. I Superglued a 3" X 6" piece of clear plexi-glass to the base of the attachment in the photo. I'll use either the router bit that you have in the Dremel now, or will use the long, spiral router bit when I relieve stocks for glass bedding or when relieving stocks for upgrades/modifications. All you have to do is set the depth of the bit and start removing material and it makes all the modifications level with the top or bottom of the stock.

That is very useful, thank you. I think I will end up building a few attachments for this dremmel to get a little more precision out of it, though this project didn't turn out bad, I would like it to be a little better. Eventually I'll have myself a decent mill and life will be better, but until then I'll find ways to get by ha ha

 

[Alibiiv]

That is very useful, thank you. I think I will end up building a few attachments for this dremmel to get a little more precision out of it, though this project didn't turn out bad, I would like it to be a little better. Eventually I'll have myself a decent mill and life will be better, but until then I'll find ways to get by ha ha

The plexiglass really helps steady the router bit, plus it makes the bottom of the routed out sections parallel with the side you're routing from. Once the plexiglass was glued on, I chucked a 1/8 " drill in the body, then screwed the fixture down onto the drill bit to get a center hole. I then took the attachment off the router body and drilled the center hole out with a 3/8drill
To accommodate the larger router bit. With the clear plexiglass you can watch what the router bit is doing.

 

[codyadams]

Small update, it's slow going but progressing!!

Got the pillars cut and bedding done, it came out alright, I tried to do the bedding of the bottom metal at the same time as the action, as well as another friends Rem 700, and the bottom metal bedding didn't come out as nice as my usual bed jobs, I may go back and fill in the gaps with some more devcon. The action bedding itself came out decent, but if I fix the bottom metal gaps then I will touch up the action as well. Even though it doesn't look the best, it has what I call a nice "click fit" when it goes together that I look for in my bed jobs, where it literally clicks as it comes together. I think it will make for a very accurate bed job, but due to my particularity I may fix it. Here are some pics

This is the part I'm especially not proud of, I didn't even take a picture after removing masking tape and cleaning it up cuz I think it looks like crap ha ha.

So here are some pics after the Leupold VX-5HD installed, along with the mag box and follower/spring for a total weight of 9.58 lbs. We may end up shaving down the beavertail forend and cutting it at an angle for sleeker looks and to drop some weight as well, but gor now, here it is.

One more little thing I found, while installing the bases, the front screw hole on the rear base stripped out at only 10 in.lbs!! So, looks like it will be upgraded to #8 base screws when it goes to the smith for a rebarrel.

Speaking of barrel!! It has been ordered. An 8 twist #3 fluted Mcgowen that will finish around 23-25 inches depending on how much the shank is able to be trimmed down.

Between the barrel that is about the same contour as what is currently on it, plus about .5 lbs dropped from the fluting, and trimming down the stock, we should be able to finish in the mid to upper 8 lbs range without much trouble.

Next, to start fitting the box magazine!!

 

[therifleman556]

Looking good! As long as you're having fun don't sweat the internal cosmetics.

 

[codyadams]

Looking good! As long as you're having fun don't sweat the internal cosmetics.

That is what my cousin said!! I'm certain it's a solid bed job, but I am just very picky about my work. I may be able to leave it alone if I just keep it covered up ha ha

 

[elkaholic]

If it makes you smile when you shoot it, what's underneath is insignificant!

 

[xsn10s]

I knew a smith that was a collector of those Marlins. Very cool thread.

 

[codyadams]

Another update. Mag box was fitted and feeds nicely with .270 ammo, just need to clean up and polish the edges. It fits snugly in the mag well. The only hurdle now is figuring out how to attach the follower spring to the floorplate, but that will wait until the rifle gets back from the smith. After fireforming a few rounds I will also likely modify the feed lips slightly to accommodate the sherman cartridge.

Last week my smith said he had it tore down and was just waiting on the reamer, which he said would be there in the next couple days, so hopefully we will have the rifle soon and can start some COW fireforming.

As a side note, we are doing a second .270 Sherman at the same time, on a Ruger m77 action. My other cousin didn't have the money for a new barrel, but his factory .270 win barrel shot sub MOA with factory ammo, and has under 200 rounds on it, so he is having it reamed to .270 Sherman. Also, he lives in California, so is limited to copper bullets, and since it is the factory barrel, is a 10 twist. So....he will be shooting the 128 Badlands Bulldozer out of a .270 Sherman!! Should be a screamer!!!

 

[elkaholic]

Very cool project and can't wait to see the progress reports.

 

[codyadams]

Small update, have the rifles back and now we're waiting on some Norma brass (should be here monday) and going to have the marlin cerakoted. We will probably start fireforming and load developement on the ruger asap, as my other cousin will be out here in Idaho on their hunting ranch next week and will be here for about 6 or 7 days, so hopefully we can have a good load worked out by then with the 128's and he can take it back with him.

So here is the marlin with the new barrel and MBM baby beast brake, what are thoughts on a cerakote color? We're thinking a light grey, swamp type green, or a fde brown type. Ideas?

 

[therifleman556]

I'd try to match the green in your stock imo