Trigger Failing to Reset, Ruger MKII?

[RogerBarker]

Gun Guys,

I own a MKII with a problem. After firing the gun seems to cycle normally and the hammer is cocked. The problem is that about 50% of the time the trigger fails to reset. Pushing the trigger all the way forward after the shot does not necessarily reset the trigger. Wiggling the trigger from side to side after the shot seems to always reset the trigger.

I suspected dirty trigger mechanism was the problem so I used Gun Scrub to blast the grip frame with trigger mechanism. This did not fix the problem. I noticed some old white grease was not remove by the Gun Scrub so I soaked the grip frame with trigger mechanism in mineral spirits overnight and buzz it in an ultrasonic bath (still in mineral spirits) for an hour at ~120 deg. F. I then gave the mechanism a light spray of Rem Oil. This still didn’t fix it. I have the instructions for internal disassembly and reassembly and am thinking this is my next step, but I really don’t want to do this unless I must.

This gun had a 2.5# trigger job done by Warren Pecsok back in 1995. I don’t really know the details of what he did other than I can see he added the trigger stop set screw. Warren may have changed some of the springs. I mention Warren’s name here incase one of you know his work well enough to know what changes he may have made during the trigger job.

So, what do you guys think? Any suggestions/advice would be appreciated.

Roger Barker
North East Ohio

[Bullseye]

Roger,

There can be a couple of causes for your problem. First, the main problem is the disconnector is failing to reset. Now we just have to isolate why.

Having a trigger job done by a reliable smith is good but tolerances can change over time. Has any thing else (trigger or sear wise) been changed on that pistol lately?

Does your trigger have a pretravel screw? This is a screw that limits the forward movement of the trigger. Does it have an over travel screw? This is the screw that limits the movement after the trigger is pulled and the sear breaks. Do you have an aftermarket trigger installed? What kind is it? (i.e. VQ, Marvel, Clark)

Here's a picture of where these screws should appear on your trigger.



The only spring that could be causing this type of failure is the triger return spring. This is the spring that sits on top of the trigger and has a round metal plunger on top of it. The plunger contacts the metal tab on the disconnector lever and pushes it up after the bolt is closed. Putting in a lighter spring here will only net you a reduction of pull about 4 to 6 ounces and is not really worth the change. Does the trigger feel like it is under a little tension when it is returning forward? Will it return forward on its own?

Wiggling the trigger is a good description and tells me that your trigger is likely not traveling forward enough to reset the disconnector and sear. Check for a pretravel screw. If you have one then, turning it in very slightly will solve the problem. You will likely have to do some disassembly to verify this modification. Here's a picture of how to remove the trigger in a Mark II/III http://www.guntalk-online.com/detailstrip.htm#trigger

Let me know what you find and we can discuss a fix from there.

Hope this helps.

R
Bullseye

[RogerBarker]

Bullseye,

Thank you very much for your post. You provided the key for fixing the problem, “disconnector failing to reset.”

I should have mentioned my Mark II is the target model. I’m thinking it has the standard target trigger with a fairly large setscrew in the center of the trigger blade that can be adjusted to prevent excessive over-travel. I see no pre-travel setscrew. All the internal parts are stock as far as I can tell.

I found that I could see the fail to fire condition by manually pulling the bolt back and then firing the gun on a snap cap. The gun would not fire on the first pull even if I wiggled it from side to side and pushed it forward very hard before pulling the trigger. However, the gun would fire after I pulled it hard, released it, and then pulled it again.

I removed the barrel/receiver to get a look at the mechanism in action. I didn’t really see any problem, but without the hammer under tension it didn’t work very smoothly. I reinstalled the main spring housing assembly. Then I could cock the hammer and fire the gun while holding the hammer back. I held the hammer back because I suspect it would damage the gun to fire it without the firing pin and bolt in place to stop the hammer’s forward travel. Anyway, I got to see the disconnector function. Mine moved up into position when I took up the slack in the trigger. Only very slight downward pressure on the disconnector would prevent it from moving up into place. When I held it down the gun would not fire just like I had been experiencing. I wondered if the disconnector might not be rubbing on the magazine so I installed it. Bingo! The magazine touched the disconnector and kept it from moving up into place on the first trigger pull. Taking the slack up a couple of times “walked” the dssconnector up into place.

I then tried my second magazine. It did not interfere with the disconnector. I measure the thickness of the two magazines at the “lower top corner”. The one that interfered was 0.364 inches and the one the worked was 0.361 inches. I put the gun back together and fired a clip with the magazine that hadn’t interfered with the disconnector. It fired on every pull of the trigger. I then put the other magazine between two strips of wood in vice and carefully pressed it down to 0.360 inches. This was a little tricky because there is some spring tension in the steel. I used the top of the strip of wood to hold the follower button so the follower was not at the top of the magazine while being pressed in the vice. This magazine works fine now too.

Thanks again for your help, Bullseye. Your comment that the disconnector is failing to reset got me to the fix.

Roger Barker
Northeast OH

[Bullseye]

Well done Roger! That was some mighty fine troubleshooting. It would've taken me considerable time to talk you down to that level of repair, we would have had to go through a lot of intermediate steps to get there. The credit is yours alone, it was you who described the problem in great enough detail to allow me to suspect the disconnector. I feel like the little boy who saw the truck stuck under the bridge and says, "Why don't you let the air out of the tires?" I didn't fix anything just made a comment. You did a outstanding job isolating and eliminating the problem.

Good on You!

Bullseye

I know a little about NE Ohio; What part are you from?

[RogerBarker]

Bullseye,

Thank you for the kind words. You’re too modest about your contribution, though. I didn’t even know what the disconnector was or that it was involved in the firing process till your post. You helped, believe me.

I live in Middlefield, Ohio, and work in Willoughby about 30 miles east of Cleveland. How is it you know northeast Ohio?

Roger

[Bullseye]

I live in Middlefield, Ohio, and work in Willoughby about 30 miles east of Cleveland. How is it you know northeast Ohio?

Ah... the heart of Amish country, I know it well. I grew up not too far from there, in what used to be a sleeply little township called Chester. My parents still live in the area. Took my younger boys out to Punderson to sled ride just a few years ago. Bit of a drive to Willoughby from Middlefield. I thought I had a drive when I lived in Chesterland and worked in Willoughby. You got that beat.

R,
Bullseye

[RogerBarker]

Bullseye,

Wow! Our paths have been close. Before moving to Middlefield 6 years ago, I lived for 20 years on Wilson Mills Rd. in Munson Township. My route to Willoughby took me up Rt. 306 and sometimes County Line Rd. I suppose you knew Neil of Pistol Pete’s. Neil died suddenly this March which was a real surprise to me. Here’s a link to his obituary in case this is news to you: http://www.news-herald.com/site/index.c ... 1849&rfi=8

Roger

[Bullseye]

Well Roger we shared some of the same turf but I left Chesterland in the mid-70's. My folks used live near to you for a time when they lived close to Wilson Mills and Heath Road.

I didn't know Neal personally but I had heard of him. My Dad knew him pretty well. Pistol Pete's store was on a lot where I used to pick blackberries as a kid. Back when I lived there, there wasn't a whole lot to Chesterland. Pistol Pete's store was across the street from where the old police station used to be, back when they only had 4 radio cars for 36 square miles. The only traffic light in the township was at the corner of 306 & 322; not counting the blinker at 306 and Wilson Mills Rd.

Funny sometimes how small the world is - huh.

R,
Bullseye

[bearandoldman]

Funny sometimes how small the world is - huh.

R,
Bullseye

Ain't that the truth, amazing as we get together and compare notes we find out all kinds of things that we have in common other thatn shooting.
Just like Bullseye and myself both being of Polich extraction and having been educated to some extent by the Felician Sisters ie. PENGUINS and having shared some of the same experiences.

[Tbag]

Bullseye, I want to thank you for having this site up and running. I was a about to post a question concerning my MKII not wanting to fire on the first pull after a fresh mag was inserted,it would fire on second/double pull, but I decided I would peer back into some old posts first. And what do I find possible fix. Plus I don't think it was happening with all of the mags, I only have about 6 of them. Time for isolation.

[Bullseye]

Tbag, That's why forums like this one are so valuable, you may have a similar problem that someone else already tackled. Roger Barker's original problem may be similar to yours. He measured the magazines and found one slightly wider than the others. This wider one was imparting just enough drag on the disconnector lever that it was interfering with its movement. Try numbering your magazines with a sharpie marker and see if one is the culprit. Roger's fix will work, just be careful. Use a dial caliper/micrometer to verify the width of the suspect magazine. Go slowly when squeezing it or permanent damage could result.

I also appreciate you bringing this back to my attention. I thought this was a one-time problem, but now that you have something like it, I'm going to add it to the Troubleshooting-Remedy page.

If magazines aren't the problem, be sure to check the trigger return spring and plunger for smooth operation. A lot of crud can build up on the return plunger and go unnoticed over time, then when there's a failure is under evaluated as the source of the problem. If your plunger hole is too tight then you can open it up a little with the next size up drill bit. Just be care full to only slightly widen the hole and not deepen it. The same goes for if you have a Pretravel screw in your trigger, be sure it hasn't walked from shot vibration. You may need a little tweaking and some Locktite applied to the screw

Thanks, and good luck isolating that problem.

R,
Bullseye