MRX Mag Mod Ruger American Ranch

[Eve]

With the release of Black Creek Labs MRX 20rd magazine I decided to take advantage and adapt my Ruger American Ranch AR bolt action to accept this new magazine. It is a relatively simple mod if you have the right tooling, I have access to a CNC mill. I modified my MDT LSS-XL chassis as well as the OEM Ruger magazine well insert. Both have functioned flawlessly so far. The magazine is snug in the magazine well, no flopping around which I prefer so not drop free. With the bolt closed it requires a good tap on the mag to seat into the catch but with the bolt open it seats perfectly. I believe the feed lips contact the bolt slightly at first but break in after working the action a few times. There is no bolt hold open with this magazine like when using AR magazines with the Ruger American which I prefer, makes it feel more like a bolt action. If anyone is interested in this I am thinking of offering a service. Any questions please ask.

Below are some pictures.

https://drive.google.com/drive/folders/1kQGinMfiUve-FaUh2LuWg8sH12qxkBdC

Edit: I posted some files to my Grabcad if anyone wants some dimensions.

https://grabcad.com/library/mrx-modification-1

 

[Mr.4570]

Is the gun forever changed to only this MRX mag or will 5 round AR mags still function correctly ?

 

[Eve]

All other magazines function the exact same. All this adds are some relief cuts to the magazine well to allow clearance for the ribs on the MRX magazine.

 

[GimpyGolden]

Funny I was going to post this very thing last week.
I don't have a mill, did mine with a dremel and files. I didn't slot mine but actually just filed in groves for the ridges.

 

[Eve]

Nice one! Yeah it's not really hard to do if you have the aptitude and the balls to cut into your gear. I was sweating doing the MDT chassis just because of the cost of making a mistake. I thought of doing slots but didn't have tooling that diameter with the reach I needed so I went with a profile cut instead. Glad it worked out for you.