View Full Version : Ruger Mk I Barrel Replacement

May 20, 2000, 07:33 AM
I have a Ruger Standard (skinny barrel), and I just found a replacement Ruger 5 1/2" bull barrel for it (clarkcustomguns.com). Has anyone done a barrel replacement on a Standard or Mk I? Any tips? Does anyone know if the American Gunsmithing Institute video on the Mk I (Ruger Auto Pistols Standard Auto, MKI & MKII) covers barrel replacement? Hate to spend the money only to find out it's a highly detailed video showing nothing more than disassembly.

Thanks for the help.


May 20, 2000, 02:44 PM
Ruger Mk I and Mk II barrels are installed with a crush fit. You'll prbably have to chuck the barrelled action in the lathe and relieve the barrel ahead of the receiver ring. Then employ your best barrel/vice wrench. This will basically destroy the barrel but it's better than harming the action.

Or box up the gun and have Clark do it.

May 21, 2000, 12:25 PM

How does one remove a crush fit barrel? Must be some way, because the barrel I am buying from Clark is a takeoff from a customer gun.



May 22, 2000, 01:19 AM
On some applications of removing crush fits you heat the part to expand it (receiver) and freeze the captive part ( dry ice on barrel causing it to contract). DO NOT KNOW if this will work on the Ruger.

George Stringer
May 22, 2000, 04:46 PM
Scott, this is really something you need to let your local gunsmith do if you don't have the proper equipment. You'll need a receiver wrench, a very sturdy bench or barrel vise and barrel block/shims made for your barrel. The barrel is held in the block and shims in the vise. The receiver is turned with the wrench. All barrels that screw in are "crush fit". That simply means that you tighten it as far as it will go and then tighten it some more crushing the last couple of thousandths. It's a fairly expensive proposition to tool up for one time use. Probably more than a smith would charge to replace the barrel for you. George

May 24, 2000, 10:46 AM
OK, I'm going to whip this dead horse a bit more. I got the bull barrel from Clark today. It's a takeoff from a customer's gun. The threads are flawless, from what I can see. If I have a good vice, could I just chuck the barrel in and turn the receiver with a (padded) wrench and give it a go? If I wrecked the old barrel, no loss, but I sure don't want to screw up the receiver. Am I kidding myself here?

May 24, 2000, 08:49 PM

Replacing a factory Ruger MkI/II barrel with a match barrel is a job for a gunsmith with good machining skills.

I found out the hard way. This job was beyond my "advanced amatuer" gunsmith status. A regular shop vise and monkey wrench aren't going to do it right and you want the job done right... Not only do you have to get the old barrel off without damaging the receiver, you have to properly index and headspace the new barrel...

Sometimes you just have to defer to the professionals!

May 24, 2000, 11:05 PM
I dunno. I may have to surrender on this one. I was tempted to press until you reminded my I have to index and headspace the barrel. This was supposed to be a low cost project to get a bull barrel on my Ruger Standard skinny barrel without spending a fortune. Adding a gunsmith to this project moves it out of the low cost arena.

Thanks for all the help.