Home Forums Hunting & Shooting Gunsmithing Let's lengthen the innards of a Ruger m77 mkII short action mag box

Well, it had to be done. My OAL was such that I wanted more room in the mag box, so here's what I did. Sorry if this has been posted before, but I haven't seen it here. This is a Ruger m77 mkII .223 rem, but would work on others with the partition inside the box:

The mag box and inner partition is spot welded together. The inside dimension (length) was 2.310" before I started. I wanted 2.400" when I was done:



I used an end mill to get rid of the weld in these spots (4 on each side of the box), marked with yellow dots:


After milling:


Separate the 2 pieces:



The yellow line on the feed lip (above pic) needs to be trimmed back .070" (approx.), to be back against the aft end of the box and open the inner portion up to 2.400".

I clean the parts and get ready to weld back together:
[img]http://i1180.photobucket.com/albums/x401/chiefbsa/IMG_0623_zps721c464d.jpg[/img]

Here are the 2 pieces as 1 again:
[img]http://i1180.photobucket.com/albums/x401/chiefbsa/IMG_0624_zps64cbe4bf.jpg[/img]
[img]http://i1180.photobucket.com/albums/x401/chiefbsa/IMG_0625_zps438b44ea.jpg[/img]

Here's the finished mag box after a little cold bluing:
[img]http://i1180.photobucket.com/albums/x401/chiefbsa/IMG_0628_zps4d7cb62c.jpg[/img]

Continued.....:




The original .223 follower works as it should at this new inside dimenstion:



I loaded some dummy rounds so they just cleared and did a function test:

[img]http://i1180.photobucket.com/albums/x401/chiefbsa/IMG_0640_zpsd654dc24.jpg[/img]
This is the 4th one in the box and they all function flawlessly. Just thought I'd share this easy fix, since I hear it all the time how you are limited to how close you can load to the lands because of the short mag box. This took about 40 minutes. Hope this helps some of you guys out there.