Rebarrel Ruger MKII

[KenH]

Hello all - I'm a bit of hobby type gunsmith. A bit of background so ya'll will know a bit about my abilities as well as limitations: I've rebarreled Remington Rolling Blocks, Mauser 98 and 93 actions in the past which involved cutting threads and setting headspace. I've got a lathe and mill as well as a few other tools.

My current project is to rebarrel a Ruger MKII pistol. I understand these barrels are screwed into the tubular receiver with a "crush fit" requiring a LOT of torque to remove barrel. I just ordered this barrel to replace the damaged barrel.



Can anybody enlighten me about the two holes in the top of that barrel? Note the bullet ramp on bottom, but at the top are two holes, one in the chamber area, and the the other in the thread area which would be past the bullet. What is the purpose of those holes?

Next, on the receiver/barrel assembly I have on the bottom there is a setscrew (takes 1/16" allen wrench) that screws into receiver. Does that just tighten against the threads? OR - is there a dimple or hole the screw tightens into? Is it put in with loctite? I've put a bit of pressure and it doesn't loosen. It is a right hand thread? I "***-u-me" the barrel is also right hand threads on a Ruger MKII?

Thank you for any and all good info

Ken H>

[Kestrel4k]

Can anybody enlighten me about the two holes in the top of that barrel? [...]

Correlates to the drilled & tapped receiver ?
(The ~last year of MkII production and subsequent MkIII production.)

[popper]

My mark III is tapped for a sight rail.

[KenH]

Thanks for the info - that does explain the holes on top of barrel. The little tubular receiver is too thin to hold much in the way of threads for scope mounting for sure. I can see why those holes would be needed. I guess they don't go all the way thru? They are blind holes?

Now, does anybody have any comments about the setscrew on bottom of receiver that looks like the setscrew is tight against the threads?

[KenH]

OK, here's a short update on the barrel project. The setscrew in bottom just would not come out. First try was to put barrel/receiver unit in a dry ice/alcohol mixture (about -95F) and soak for an hour to get good 'n cold. Next play a little heat with hand propane torch around receiver setscrew hole hoping that would free screw. No joy - the little 1/16" allen wrench just wouldn't turn screw.

Well, no choice now but to drill setscrew out. Drilled nicely. Soak barrel/receiver unit for another hour in dry ice/alcohol mixture, quickly clamp barrel in vise with aluminum jaws protecting barrel - clamp tight! Play hand propane torch over receiver to expand receiver at threads while applying pressure on wrench on receiver. This uses a 1/2" aluminum bar to fill slot in receiver with cresent wrench on aluminum bar so it won't mar the receiver. A bit of heat, barrel screws right out.

Now, one the new barrel gets here Monday it will be screw in - and "hope" the new barrel will index close. I'm not sure how much the barrel can be turned to allow indexing. I would think the ideal would be for barrel to screw in stopping perhaps a 1/4 turn so only a small amount will need to be turned from shoulder of barrel. I'd think worse possible condition would be for barrel to screw in just past index point so shoulder would have to be relieved enough for barrel to turn almost a whole round which would put barrel face further into receiver.

Can anyone give any guidance here?

Thanks again for any help.

Ken H>

[Der Gebirgsjager]

Hi -- wish I could offer you some advice based on experience, but can't honestly do so. I do own one, but it's the first, original model that some now refer to as a Mk I, and it doesn't seem to have the hole features you are talking about. I tinkered with guns for 30 years and was never asked to rebarrel one, but I do recall a fellow student in the gunsmithing school I attended having a terrible time getting the original barrel off of one like mine that he wanted to install a bull barrel onto. So, here's a little story for you that might be worthy of consideration in the future. In the 1990s a fellow brought in a Mini-30 that he had loaned to a "friend". The friend fired lots of Chinese corrosive 7.62x39mm through it, but cleaning was something he just didn't believe in, and when the owner got the rifle back well over a year later the bore was rusted completely closed. I attempted to buy a replacement barrel from Ruger, and they refused to sell me one, but offered to rebarrel the rifle for $85, and that included the cost of the barrel. I really didn't have a choice, so sent it to them and it came back in just a few weeks looking like new. The lesson I came away with from this incident was that Ruger would do the job cheaper than I could, and thereafter I sent all Ruger firearms that needed rebarreling back to the manufacturer. They have all of the specialized tools in house to do the job efficiently. Good luck with your project.

[JimB..]

I predict that in a week you’ll be posting about remounting the original barrel, drilling it out and installing a liner.

Not sure how to get it to index properly AND have the predrilled holes in the barrel line up with the holes in the receiver. Sure they’ll both be on top, but if you take anything off the shoulder they won’t line up. Seems that it’s either going to drop in, or not.

I hope that either the barrel or the receiver isn’t drilled.

[KenH]

The receiver isn't drilled so the holes in the top of the barrel above will be covered by receiver so that's not a problem. The only thing that needs to line up is the extractor groove and bullet ramp. At this point, I'm not at all sure this new barrel will fit at all. The old barrel wasn't any problem to unscrew..... Once I soaked in dry ice solution and put a little heat on receiver. Didn't take much heat at all - no discoloration at all.

The setscrew on bottom isn't factory I'm pretty sure - never heard tell of it before, and this MkII was "diddled" by a "gunsmith" 20 yrs ago who I expect installed the setscrew.

The idea of shipping back to Ruger is a GREAT idea - I'll follow up with Ruger to see if they'll install a barrel and cost.

Ken H>

[KenH]

One more update for this thread. Got barrel today, perfect fit. Hand snug barrel was about 45 degree from index. Cleaned shoulders good, put a pipe on vise to tighten wood blocks on barrel, just barely able to get barrel tight enough to index. Looks just about perfect. Ran a mag thru rapid fire and didn't miss a beat. Inside and out the barrel looks like factory. I'm a happy camper now.

I was going to call Ruger to see what they had to say and cost, but decided to wait until barrel got here. No reason to call now.

Ken H>

[Petrol & Powder]

Excellent !!

Pictures?

[KenH]

Here ya' go. I'm happy with how it looks - just like factory.

[EMC45]

Looks excellent! Just like factory.

[Texas by God]

Happy,happy. Easy is good.

Sent from my SAMSUNG-SM-G930A using Tapatalk

[KenH]

Thanks for compliments - rebarreling those Ruger MK's are not so hard after all - as long as the new barrel will index ok. Getting the old barrel off is a snap with dry ice/alcohol mixture and decent barrel vise.