Loose barrel to frame on Ruger Mark pistols.

[raw6464]

This procedure will fix a loose receiver to barrel fitting on Mark pistols by taking up all the space worn by wear and tear between the square receiver lug hole and the frame lug it attaches to.

Step 1. Break the gun down to receiver/barrel and frame.
Step 2. With alcohol or acetone clean out the square hole on the barrel that the lug on the frame fits into, no oil based solvents please.
Step 3. With a cotton swab place a film of oil on the lug in the frame… so nothing will stick to it.
Step 4. Mix a small amount putty epoxy, the kind you can form and shape.
Step 5. Place a small amount of the mixed putty epoxy in lug hole on the barrel.
Step 6. Reassemble the barrel to the frame and make sure you install the bolt stop completely in the assembled barrel receiver. You may have to bang the front of the barrel to get it far enough down to install the bolt stop. If you can’t reassemble the bolt stop you’ve probably put too much epoxy in the lug hole and the receiver is not going far enough down on the frame… remove excess and retry.
Step7. After you’ve reassembled the gun, disassemble it again.
Step 8. Now remove any residual putty epoxy from the barrel and frame that spilled out of the lug hole. You just want the epoxy to be in the lug hole on the barrel.
Step 9. To let the epoxy fully cure leave the gun disassembled overnight before the final reassembling.

[bgreenea3]

I've had good sucess with the beverage can shim method.

1. empty beverage can (you may need to empty a few to get the correct thickness of shim )
2. cut can open and cut out "tombstone" the width of pistol frame and the length of the plunger on trigger to just short of the front of frame
3. cut square hole in the tombstne the size of frame lug.
4. trim to fit
5 put tombstone over lug and put upper on normally. fit may be tight you might have to convince it on.
6. check for function


the shim has the bonus of keeping crud out of trigger group and has been called a blast shield by others.

[bgreenea3]

other folks say the only right way to fix a loose fit is to squeeze the frame together in a vise frankly that scares the snot out of me, I would ruin it.


your epoxy method sounds good. but when the epoxy crack or chips those chunks could get into the action and jam the pistol.

[bigfatdave]

I wish I had this problem!
I still have to bonk off the barreled receivers from both of my mkIIIs, and they've been down and together more times than I can fathom.

A note to the casual reader:
Don't panic if you have a bit of slop, the sights are mounted to the barrel rather firmly.

other folks say the only right way to fix a loose fit is to squeeze the frame together in a vise

Fun! How's that work on a 22/45?

[raw6464]

Squeezing the frame does work... but you need to be very careful and patient applying pressure a little at a time... we're talking 1-2mm here.

As far as epoxy breaking off in the frame. I have not found that as a problem as long as the gun is assembled there is no wiggle room for any epoxy to break away into the frame. You just need to keep this procedure in mind when you take the gun down... it's a point that needs to be examined each time the gun is disassembled.

[bgreenea3]

I wish I had this problem!
I still have to bonk off the barreled receivers from both of my mkIIIs, and they've been down and together more times than I can fathom.

A note to the casual reader:
Don't panic if you have a bit of slop, the sights are mounted to the barrel rather firmly.

other folks say the only right way to fix a loose fit is to squeeze the frame together in a vise

Fun! How's that work on a 22/45?

I would hate to see someone try it.....maybe some gentle heating to soften the plastic

[arizona-hermit]

I wish I had this problem!
I still have to bonk off the barreled receivers from both of my mkIIIs, and they've been down and together more times than I can fathom.

A note to the casual reader:
Don't panic if you have a bit of slop, the sights are mounted to the barrel rather firmly.

other folks say the only right way to fix a loose fit is to squeeze the frame together in a vise

Fun! How's that work on a 22/45?

So true BFD,

I have always found that bull barrels have a much tighter fit than the lil pencil barrels. Every single pencil barrel I have ever owned was 'loose' after a few years. None of the bulls I have are and many have been around 20-30 years now.

Just my experience, others may vary.

[ruger22]

Just to be on the safe side, I always put a little grease on the lug and in the hole, using a swab. Still tight after several dozen teardowns.

[raw6464]

Just to be on the safe side, I always put a little grease on the lug and in the hole, using a swab. Still tight after several dozen teardowns.

I used grease for a while and it works. The only down side was cleaning the grease up after shooting.

My barrel to frame became loose after I sent the barrel out for re-bluing. They polished the barrel a little bit in prep for the bluing, the polishing took some metal off the barrel. I did squeeze the frame in a vice and it did tighten up the fit. But the epoxy in the lug hole put the icing on the cake and it's holding up very well.