Mounting a Scope on the Universal M1 Carbine

Universal M1 Carbine Information Page     MaxIcon

A scope on a Universal M1 Carbine, or any M1 Carbine?  Seems a bit pointless to most people, given the accuracy of the rifle design.  Still, as my eyes age, I find a scope makes it a lot easier to get decent groups on anything, and the Universal is no exception.  I've been putting various optics on more and more of my guns, and the Universal is a favorite plinker of mine.  If not for the ammo cost, it would be right up there with the SKS and Mini 14 as a fun shooter.

The Universal M1 Carbine comes drilled and tapped for a scope mount, with a plastic filler plug for the 4 holes on the left side of the receiver.  Mounting a scope requires 2 pieces, both available from Numrich at  The Numrich part number for the set is 574040 (Mount With Base Set, $28.80 - prices are from 2003).

The scope base is a special part for the Universal M1, and only available from Numrich, as far as I know.  Someone on the 'net said this mount won't work with wood handguards, only metal. Mine is metal so I can't vouch for the wood.

The top half of the mount is a Weaver model 48409 M, which can be seen here: or (800 kB).  If you look on Numrich's Universal M1 locator chart, 545020B comes up, which is just the Weaver 48409 M side scope mount with 1" rings ($13.40). This is a drill-and-tap mount for a GI M1 carbine, I believe, and needs the side mount for the Universal holes, which comes with it in the set above.  The rings are standard Weaver stamped steel and not real high quality, but mine's been sturdy enough, and hasn't had any problems with loosening or shifting with a dab of Loctite on the mount screws.

It might not fit a red dot, depending on the tube, as the 1" rings are spaced more for traditional scopes and aren't adjustable. There's 3.7" between the inner edges of the rings, and the rings are 0.75" wide, so the scope would need to be more than 5.2" long to fit fully into both rings.

I held up an Ultradot to it, and if you mounted it so that the ridge at the back of the scope tube cleared the rear ring, the tube would only extend half-way into the front ring. This looks like it would work on the Ultradot, since the front of the tube is the same diameter all the way, but you'd want to remove the ring that protects the sunshade/filter threads, and tighten it carefully.  It might work better with the sunshade screwed in to give the front rings more grip.

It doesn't look like it, but with my Leupold VX1 3-9x40 mounted, the rear sight clears the rear scope bell by something like 1/16". You can still use the iron sights with it mounted, but just barely, and the elevation is all the way down. The top half of the mount comes right off and lets you use the iron sights. A smaller scope would give more clearance, of course.

Another option for more flexibility would be to make an adapter to go between a standard Weaver/Picatinny rail and the Universal-specific mount. That's on a future project list, and I'll be looking into inexpensive rails to experiment with.  Ultimak makes a scout mount for the GI M1 Carbine, but unfortunately, they say it won't fit a Universal. 

Here's the full setup. The screws for the bottom part of the mount needed to be shortened 0.2" to avoid binding the bolt, but you'd want to check fit first. I put a touch of Loctite on them, and they're still nice and tight, after 400-500 rounds.  Note that there are only 3 of the 4 screws installed, as the tolerances were a bit off on the last hole.


Here's the backside, and you can see that the brass tends to ding both the mount and the adjusting rings for the scope. It looks bad, but hasn't affected the operation of the rings yet. You could add a brass deflector on there if you wanted with a bit of drill'n'tap or some JB Weld.


Here's the top half of the mount on the scope.


Here's the bottom half of the mount on the gun.  Note the fine adjustment work on the rear sight, performed by a previous owner.  The sight's a bit wobbly in the dovetail, so I'm not sure why it's got so many hammer marks on it...

Other Universal M1 Carbine Scope Mount Options

I haven't tried any of these, but here they are, current as of 7/06: - Weaver mount that replaces the rear sight.

Any corrections, comments, or changes?  Send them to  I'm particularly interested in personal experiences with what works with the Universal M1 Carbine.