Ruger MK II Target disassembly question

youtube has scores of videos to look at.

Agsalaska said:

I just got it. I said to heck with the rubber grips and stuck it in a vice in my garage. That was an insane amount of pressure I had to put on it to get it out. I am going to soak it in ballistol and see if that make it any easier.

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Before reinserting the pin, use a tight fitting drill bit, turned by hand, to “ream” the fit between the upper and lower, so the pin will no longer bind so tightly. You can also hand fit the upper to the lower at the forward lug and the side rails, which makes a HUGE difference in the tension in the fitment between the two.

Doing this will ensure the pistol comes apart easily and quickly in the future.

I have a number of MKII Rugers. Getting the mainspring pin out of the receiver can require some “encouragement”. Under no circumstances would I ream the hole in the receiver. That is a critical dimension that should never be altered. Nine times out of ten, it’s the yoke in the bolt spring that hangs up on the receiver pin. I always put a little light grease on the top of the pin to help it get past the bolt yoke on reassembly. Make sure that you push the back of the bolt all the way up against the breech face of the barrel and hold it there when attempting to reassemble the pistol. It is sitting there free and will cause the pin to hang up on reassembly if it’s even backed out a hair.

Were I you, I would remove the grips and put the pistol in a padded jaw vice. Don’t clamp down too hard. It just needs to be firm. Open the mainspring assembly and pivot it up as far as it will go. Take a brass drift punch and put it on the top of the large pin sticking up out of the frame. With the mainspring assembly rotated out as far as it can go, give the drift punch a sharp whack with a hammer. You’re not driving a railroad spike. A sharp whack with a 1/2 ounce hammer will do the trick. That should start the pin out of the frame. At this point, you should be able to remove the mainspring assembly. Reassembly is not hard but does require some practice. Just watch the videos on YouTube. Make sure the hammer is all the way forward and that the hammer strut is free so that it will swing freely. With the hammer all the way forward, grab the pistol with your non-dominant hand with the barrel pointed upward at about a 45 degree angle and swing the mainspring assembly back into the frame. You need to capture the hammer strut when you close the mainspring assembly. You will feel the mainspring compress as you push the assembly back into the frame. If you don’t feel any spring tension, you have not captured the hammer strut, so repeat the process.

With the receiver pin fitting as tight as yours does, you may need to give the mainspring assembly a whack with a small brass hammer to get the pin back into the frame. Not all that hard...just requires some practice.

whatnickname said:

Under no circumstances would I ream the hole in the receiver. That is a critical dimension that should never be altered.

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1) Gunsmiths alter “critical dimensions” every. single. day. as a matter of essential practice.

2) But frankly, the bolt stop pin really isn’t much of a critical dimension, in any way. All it does is retain the upper to the lower (ever noticed how non-critical the fit of AR uppers and lowers really is to their function) and stop the bolt in the upper receiver. These do nothing at all “critical” for headspacing, fire control, or any other function. But when properly sized pin stock does not pass through the receivers because the relatively loose production tolerances caused the pin bores to fail to align, fixing that alignment is quite simple. In many cases, simply lapping with a pin stock mandrel will do the trick, but reaming helps. Considering this a critical dimension and recommending this should never be altered indicates a gross misinterpretation of the mechanical design of the Ruger Mark Series pistols.

When bits of kit don’t fit, fit the bits.

There is absolutely no risk and no damage to be done by properly fitting the early Mark Series Bolt Stop Pin (what you’re calling the receiver pin) to improve takedown. It’s tolerance work that Ruger should be doing at the factory, but does NOT do because it adds labor and cost.

Have the same pistol. Was a bit stiff the first few times but loosened after several cleanings. I always grease it well before re-inserting and that helped. Once you get it down and really think thru how it all works, you'll be amused at all the "Ruger Mark*" disassembly/assembly horror stories. It is a very clever design!

Some are tight, some are loose. My SS M II bull barrel has been tight from the day I bought it.
Others I have just fall out.

Simply take a plastic, brass or wood dowel and tap down the bolt stop pin after you have housing latch swung out

Putting it back is more fun You have to top the assembly back up, while keep the angle of the dangle correct.

tap the top of the bolt retainer with a brass punch to get it to pop out. mine did the same thing. after fighting with it a few times, I took a q tip and looked for burrs and there were some. I just used a small file and a stone to smooth off the burrs, and it still takes a good bit of a pull to get it to come out, but I had what you had and it isn't right. I had burrs on the pin and the hole through the bolt. I touched it up with Oxpho Blue after removing the burrs and smoothing it a bit and it will probably never be an issue again. I don't really like pulling on things too hard, I've cut my fingers open and banged my knuckles too many times over the years.

It is frustrating enough to try to figure out if you have the hammer in the right position for the right operation, that pin being too tight and sticky doesn't make that easier IMHO. Once you've done it a few times, it starts to seem almost too easy to have ever been so tricky to do the first few times. That's been my reaction anyway.

Agsalaska said:

They say pull hard. I did. They say it can be tight. It is.

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It's not exactly tight. . . the nub at the back of the return spring guide seats into a detent on the pin. A gentle hammer tap on the pin head will do wonders to pop the pin over the rim of the detent.

And if you think this is bad. . . try disassembling a factory-tight GP100. They must have bought Kimber's old sight press to seat the trigger group.

Agsalaska said:

I just got it. I said to heck with the rubber grips and stuck it in a vice in my garage. That was an insane amount of pressure I had to put on it to get it out. I am going to soak it in ballistol and see if that make it any easier.

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Ballistol makes everything better, contrary to what my shooting partner thinks. What does he know, he's an ignorant old man. Good thing he can't read.

I'd skip the drill bit. I would just take out the spring and put it in a few times. It will loosen up. If I had trouble getting it started out, I'd give a few pecks from the top with a brass punch and/or brass hammer. I would also consider polishing the bolt stop.

edwardware said:

A gentle hammer tap on the pin head will do wonders to pop the pin over the rim of the detent.

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This is what is SUPPOSED to happen. But factory tolerances being what they are, it doesn’t always work out that way.

I’ve had Mark series pistols come across my bench which simply wouldn’t come apart, even using a hydraulic press against the bolt stop pin. I also have a screw press fixture I made to drive stubborn Mark series pistols apart. Those which refuse made a one-way trip back to Ruger and were replaced by the Mothership as they couldn’t get them apart either.

Checking and correcting alignment and fitment on a receiver set seems like it shouldn’t receive so much protest. We fit slides and barrel blocks, we fit bolt lugs and barrels, why are guys so averse to fitting problematic Mark Series pistols? Or are guys just unwilling to accept that not all Mark Series pistols leave the factory with ideal tolerances for simple takedown as they were designed?

JohnKSa said:

How do they get them together at the factory? The thing is symmetric from the standpoint of installation/removal. If it takes that much force to get it apart, it should have taken that much force to assemble it.

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No idea. Probably the same gorilla Remington used to use to put over 150ft.lbs. of torque on their barrels.

But I have had multiple Mark Series pistols which even my press wouldn’t open, and Ruger replaced them all as they too couldn’t get them apart. I tend to assume someone at the factory used a bigger mallet to whack the upper onto the receiver to make them fit when tolerances were out of whack than I’m willing to use on a customer muzzle (and I DO use a pretty damned big mallet in my attempts before abandoning hope to send them back to the mothership, hence also exhausting efforts like the screw jack and hydraulic press fixture).

Make sure the magazine is removed, chamber is cleared, point in a safe direction & dry fire- now you can start removing the main spring housing.

JohnKSa said:

If it takes that much force to get it apart, it should have taken that much force to assemble it.

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That reminds me of the time a fellow put all 120, 10-32 stainless SHCS into the bulk head that encloses the fuel bladder in a area Reynard Indy car, without a drop of anti seize. Went in with a finger, I think 5 came out without breaking of. Doesn’t seem like it should be that way but it is sometimes.

For the pistol, I never found taking them apart a problem. Many years ago learned there was a certain way to hold them to put them back together though.

Much like some of Ruger revolver. Try to swing the trigger guard down and out! On some it takes a lot of force. There use to be a tool called a Ruger Popper! Basically a screw driver pry tool.

https://www.brownells.com/aspx/learn/learndetail.aspx?lid=10413

edwardware said:

It's not exactly tight. . . the nub at the back of the return spring guide seats into a detent on the pin. A gentle hammer tap on the pin head will do wonders to pop the pin over the rim of the detent.

And if you think this is bad. . . try disassembling a factory-tight GP100. They must have bought Kimber's old sight press to seat the trigger group.

Click to expand...

You got that right about Kimber sights. You can’t get one of those sights out with a stick of dynamite!

Varminterror said:

1) Gunsmiths alter “critical dimensions” every. single. day. as a matter of essential practice.

2) But frankly, the bolt stop pin really isn’t much of a critical dimension, in any way. All it does is retain the upper to the lower (ever noticed how non-critical the fit of AR uppers and lowers really is to their function) and stop the bolt in the upper receiver. These do nothing at all “critical” for headspacing, fire control, or any other function. But when properly sized pin stock does not pass through the receivers because the relatively loose production tolerances caused the pin bores to fail to align, fixing that alignment is quite simple. In many cases, simply lapping with a pin stock mandrel will do the trick, but reaming helps. Considering this a critical dimension and recommending this should never be altered indicates a gross misinterpretation of the mechanical design of the Ruger Mark Series pistols.

When bits of kit don’t fit, fit the bits.

There is absolutely no risk and no damage to be done by properly fitting the early Mark Series Bolt Stop Pin (what you’re calling the receiver pin) to improve takedown. It’s tolerance work that Ruger should be doing at the factory, but does NOT do because it adds labor and cost.

Click to expand...

I wouldn’t do it. Shooting the pistol makes the bolt hammer the breech face of the barrel. That tight fitting receiver pin is the only thing that prevents the repeated action of the bolt from moving the upper receiver forward on the grip frame… and it will do it over time. Take off too much material out of the hole in the frame and I can see all kinds of problems from headspace issues to feeding problems. Besides, I’ve never seen one yet where the hole in the receiver was too tight. The problem is always getting the pin past the yoke on the back of the bolt spring. Reaming the receiver hole has nothing to do with that and nothing is gained by doing this. Best way to test your theory is to run the pin through the hole with the receiver off the frame and the bolt out. Haven’t seen one yet where the hole in the receiver hole was undersized!

whatnickname said:

Take off too much material out of the hole in the frame and I can see all kinds of problems from headspace issues to feeding problems.

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This assumption is false, as it’s simply not how the pistol functions. The bolt stop pin is not the forward stop for the bolt. As you stated in your own claim, the receiver is the forward stop for the bolt. The bolt will continue carrying forward to stop against the receiver, regardless of the bolt stop pin.

The job I describe is to CORRECT the incorrect dimensional fit of the receivers. We’re not introducing additional clearances or slop, we’re fitting the receivers to achieve the dimensional congruence they were designed to have, but due to production tolerances, unfortunately did NOT.

whatnickname said:

The problem is always getting the pin past the yoke on the back of the bolt spring.

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This too is a false claim, as this is not “always” the sole reason for excessive resistance to disassembly. Yes, many people do struggle with overcoming the bolt spring on the ramp in the bolt stop pin - but common “whack it with a punch” solution resolves this. However, in some cases, the receiver bores cannot be aligned with reasonable assembly force to index the upper bores to the lower. The first solution SHOULD be to hand fit the receiver rails and forward wedge to allow alignment, but sometimes we end up getting on the edge of “too loose,” and the receiver bores simply don’t align as freely as they should. When an owner is stuck HAMMERING their receivers together and apart - rather than simply tapping apart or together - to achieve alignment of the pin bores, we know the tolerances are out of whack. Super simple fix.

If it doesn't want to come apart ... leave it alone ... Do NOT Force it !
I owned and shot my Ruger MKII for about 10 years ... every time I cleaned it (after each range trip) I would attempt to take it down ... the bolt retainer never wanted to pull out with the force I exerted with my hands ...
so I just left it alone and cleaned it best I could ... after about 10 years of this ... one day I pulled down and the pin popped free !
This is what my old Daddy once told me about this kind of thing
" If something doesn't want to come loose ... don't force it , just leave it alone. "
Forcing things usually results in broken parts !

also ... the hard part isn't taking it apart ... the hard part is the MKII is a sun of a biscuit to get back together ... and I've owned a MKI Target since 1974...no trouble with it ...But the MKII made me say cuss words and throw a tool or two before I discovered the right way to hold my mouth and the "secrete" .
Gary

My mark 2 is stainless I've only completely taken it down one time for the initial cleaning I usually just blast the receiver out really well it's run for years without any issues

Try this
https://www.hammerstrutsupport.com/

I have no affiliation with this company but this works for me.