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Hey Mark II experts out there…I need your help.
Problem: Ruger Mark II trigger won’t drop hammer unless I hit the pistol with a mallet.

Last week I bought my first Mark II, a nice blued 10” target model. After getting it home, I discovered that it had an intermittent problem where it won’t drop the hammer when I pull the trigger. The first time this happened, I cycled the bolt a couple times and then the hammer fell when I pulled the trigger. But the problem started to happen more frequently and cycling the bolt wouldn’t cure it. So I thought I’d field strip the pistol to take a look inside. Field stripping and reassembly were a challenge because it was difficult to drop the hammer - Bullseye, thank you for the great troubleshooting guide and pictures. Nothing seemed out of the ordinary inside, but after reassembly I still had the initial intermittent problem, pull trigger - no click.

So I decided to do a complete internal teardown and clean everything up. This is a mid-1980’s pistol and it was pretty dirty inside. Again, thank you Bullseye for the excellent instructions and pictures. I got everything cleaned up and reassembled…but again had the same initial problem…no click. Then…I hit the left side of the pistol pretty sharply with the heel of my hand…and the hammer clicked when I pulled the trigger. I cycled the bolt and tried this again and it worked. So now, about 80% of the time after cycling the bolt, the trigger will not drop the hammer. But, if I followup with a light hit to the side of the receiver with a rubber mallet, something happens internally so that the next pull on the trigger will drop the hammer. I have not yet fired the pistol.

Any suggestions? I’ve searched but not found a thread with this problem and I really don’t want to carry a mallet around with me while hunting or at the range! Thanks in advance for your help.

Welcome to Guntalk-Online.

There was another fellow a while back who had a similar problem with his Mark II. When you did your detailed stripping did you clean out the inside of the frame with a rag? Sometimes the shipping oil or old preservative builds up and causes the disconnector lever to stick. A sticky disconnector can cause the problem you've described. Equally responsible is the plunger found in the top of the trigger. If this is sticking the plunger cannot force the disconnetor upwards to engage the trigger, much like you've described. The top of the trigger is highly susceptible to powder residue from the chamber and will cause the plunger to bind. There is a relatively small spring underneath the plunger that can get gummed up too. I have taken a #9 twist drill and cleaned up the hole (like I've described in this post http://www.guntalk-online.com/forum/vie ... 8273#18273).

R,
Bullseye

Could it be the trigger overtravel stop is udjusted too tight & not allowing the trigger to pull forward at the top to drop the trigger bar/conector??
The factory Over Travel screw is in the top front of the trigger & can't even be seen unless your looking for it..
Good Luck!!
You asked at the right place..
Gary

This problem cannot be caused by the factory overtravel stop screw. The OT stop is at the top of the trigger and therefore is above the trigger's pivot point on the pin. When the trigger is in a static state, fully forward, the overtravel stop is at its furthest point away from the front of the trigger well. It is only when the trigger is moved rearward that this stop screw contacts the trigger well face and restricts movement.

The OP has not indicated any aftermarket parts in his pistol, so I am not including an adjustment for a pretravel stop. A pretravel screw is below the trigger's pivot point and therefore makes contact with the trigger well face when the trigger is static. This adjustment could affect how the disconnector bar interacts with the sear.

If the pistol has a VQ sear installed then it could be a possible source of the problem.

R,
Bullseye

Thanks for the replies - I’ll answer all of the questions so far. When I did the detailed stripping, I thoroughly cleaned all parts, levers, springs and the inside of the frame. There was some thick oil (?) between the frame and the bolt stop lever that I cleaned up. To the best of my knowledge, there is no more powder residue, dirt, or grime on any of the internal moving parts. Everything seems to move freely. I also have an ‘07 Mark III that I used for comparison. With the mechanical differences noted, both trigger/plunger/connector systems seemed to function the same.

I believe the Mark II is a stock pistol with all original parts. There is no pretravel adjustment screw. I’ll go over it all once again tonight paying close attention to the disconnector and the trigger plunger. If still having trouble I’ll post some pictures. Thanks.

Forum

Is it possibly the hammer pin is too short and workin out on the left side. When he snacks it the pin reseats properly?
Sounds like you need to pull the barrel off and put the mainspring back in. Run thru the firing and watch the sear/hammer/disconnector relationship. Be sure and catch the hammer.
J

When you cycle the bolt and release the trigger you should hear a 'clicking' sound; that is the disconnector resetting on the back of the sear. If you don't hear it, then try pushing the trigger forward manually with your finger. If it moves a little and you hear a click then your trigger is not returning fully forward. You can also check this with the receiver off the frame and the mainspring housing installed. Just push the top of the disconnector lever down and pull the trigger rearward and hold it. Slowly release the trigger and you should see the disconnector lever pop up; this is the click sound you hear as it engages the back of the sear. If your not getting the disconnector to rise then either the plunger or plunger spring is not doing its job or the sear is not in the same place as it was when the pistol left the factory. This could be an indication that someone altered the sear by improperly stoning the engagement angles causing a problem.

R,
Bullseye

Thanks for the great suggestions. Hopefully this update will help.

First, I've rechecked, and the working parts (plunger, plunger spring, connector, etc) are clean and freely moving.

Second, with the pistol fully assembled and after getting the hammer to drop (with mallet technique), if I hold down the trigger while cycling the bolt, then release the trigger, I hear the click and the next pull of the trigger will drop the hammer. I can do this repeatedly without failure. Hold trigger...cycle bolt...release trigger...hear click...pull trigger which drops hammer...hold trigger...and so on. But, if I do not hold the trigger down while cycling the bolt, then "it" does not reset and I have to tap the pistol with a mallet to get the trigger to work. But I found out that I can also get it to reset by wiggling the trigger. If I do this enough, I eventually hear the click, and then the trigger works.

Third, I also tried the "barrel off - mainspring on" test. If I depress and hold the disconnector lever... pull and hold the trigger while releasing connector...then when I release the trigger I do hear the click and see the disconnector lever pop up. Functions the same as my Mark III. (Got frustrated for a few minutes when I couldn't get the mainspring on the frame. Realized I was trying to put the MkIII mainspring on the MkII )

One other note: when I push down the disconnector lever it feels a bit "gritty" even though It seems to move freely. Pushing down the disconnector lever on the Mark III doesn't have the same gritty feel. But again, they seem to function the same.

Just field stripped and reassebled again and its working a bit differently. Now, with the pistol fully assembled, after cycling the bolt the trigger will not drop the hammer (just as before), but, when I pull fully back on the trigger I hear the internal click. Then if I release the trigger and then pull the trigger, the hammer will drop. It does this repeatedly/consistently.

As with my last post, I can still cycle the bolt while holding the trigger down, release the trigger and hear the internal click, then pull the trigge to drop the hammer.

i would look at the plunger/ spring on top o the trigger, I had a simalr prooblem with a PPK/s only on closer inspection found that the triger spring was broken so it was not resetting the disconnector to the sear. you may be having a simalar problem check the plunger and spring that push up the disconnector there may be some gunk or a burr in there that is causing it to stick and not push the disconnector back up into its place

How much side to side movement do you have in the hammer/bushing/pin. Is there more than 1/8"? The reason I ask is my MKIII had a lot >1/4" with this much play you have an additional ~0.004" to 0.005" of slack that needs to be made up to drop the hammer.

Is the disconnector straight and flat. I have seen the with a little warp which will make it bind against the frame. If this is not straight you are loosing distance make the disconnector shorter by a few thousand's, but this all all your needing.

Do you have enough post travel in the trigger to adj the disconnector? This would require filing very very lightly on the tip that contact the sear. Bullseye can instruct you on this a lot better than I can...

The plunger and spring on top of the trigger are clean, complete, and moving freely.

There is less than 1/8" of slack on the hammer pin.

The disconnector appears to be straight and flat.

How would I check to see if I have enought post travel in the trigger to adjust the disconnector?

When I have more time tomorrow night, I plan to do another compete tear down and close inspection of all parts.

Thanks and please keep the suggestions and help coming.

BTW, there is a bright side to this story. I now understand the internal workings of the Mark pistols much better than I ever did. I've always had to blindly follow the Mark III's step by step field strip and assembly instructions...not knowing why I was inserting mag, pointing pistol down, holding trigger down, blah, blah, blah. Now I can do it wthout following the instructions because I know wha't going on inside the pistol.

Could it be that someone has cut the trigger spring down??
The one in the top of the trigger..
I have read were some guys use an "Ink Pen" spring cut down for this..
The trigger spring works the disconector/trigger bar..
Good Luck!!
Your on to the answer..
Let us all know when you figure it out.
Gary

Well, you are on to the problem. It is definitely the disconnector failing to reset on the back of the sear. There is some interference on the disconnector lever causing it to bind and not reset. Your noticing the gritty feel on the disconnector is the problem. There are four points to check. One is the plunger and spring in the trigger. Two is the disconnector pivot pin in the top of the trigger. It should not be binding and the disconnector should pivot easily when installed. Three is the inside of the frame where the disconnector lever touches. It should be a smooth surface, no burrs or grit. Four is the squared hole in the disconnector where the hammer bushing rides. If the hammer bushing is hanging up inside this hole the same effect will happpen, like you're describing with the trigger not engaging. You can use a Sharpie magic marker and color the side of the disconnector that faces the frame. Re install the disconnector and run it through several test dry fires, then open and recheck looking for any shiny scrape marks on the lever. This technique will isolate and reveal where the binding is happening. It will also work for the part of the lever where the hammer bushing touches. This will reveal if the source of binding is the bushing.

R,
Bullseye

- Plunger and spring are not the problem.
- Disconnector pivots freely in the top of the trigger.
- The inside of the frame where the disconnector lever touches is smooth with no burrs, grit, etc.
- That leaves the area around the hammer bushing...

I colored both sides of the disconnector lever with a blue sharpie, reassembled, and dry fired several times. There was a bit of wear but it did not seem excessive. Here's a picture of the outside of the disconnector.
(alt+p)

(Posting this first to see it the photo link works)