[dingode]

I bought a MKI a bit ago and am having a few issues. The sear isn't resetting when it's fired. I can cock it and dry fire it all day long. But if I simulate shooting by not releasing the trigger after a dry fire and racking the bolt again the sear wont engage the hammer. After releasing the trigger, I can wiggle it a hair forward, and I'll hear the sear click into the hammer, and it will fire.

I've found a few potential things that could be causing this.

#1. Sear spring stop pin is bent.
#2. Hammer pivot pin is bent (have a feeling this is the cause of my problems as I feel it isn't allowing the disconnector to freely move around the bushing or is holding the hammer a bit off)

I can find the sear spring stop pin all over the net. But I cannot find the hammer pivot pin anywhere. Will the MKII pin work in a MKI? I see it isn't a plain dowel, but has a head on it. I haven't looked it up yet, but while replacing pins I figure I may as well go ahead and replace the sear pivot pin too. Can it be found online anywhere? And, it there a chart somewhere showing compatability between MKI and MKII/MKIII parts?

Any other ideas to fix the problem would be appreciated too. I've not done a total dissassembly on this gun before, but I think I'm capable of it if need be.

 

[TimN]

Sounds like a seer spring to me. I just finished restoring a Mark I. My advise is disassemble the gun and inspect it. You should see obvious signs of parts being bent. A word to the wise. This may be a job for a gunsmith. There is a keeper on the trigger on the inside of the trigger pin that has to be removed be before it can be driven out. It can be a real pain to put back in place on reassembly. A seer spring is like $3.00 from Midway USA. I believe the Mark I, II and III pins are the same.

Here are some links that might help you.

MidwayUSA

http://www.ruger.com/products/_manuals/markI.pdf
Good Luck

Tim

 

[dV8r]

Also nearly all parts of the MkII and some from the MkIII will interchange with the Mark I and Standard. I have two of the Standard model.

 

[Bullseye]

A couple of things. First, if you don't release the trigger after dry-firing it won't reset by design. The disconnector is designed to prevent the trigger and sear from engaging unless it is rotated forward and the bolt is closed. The trigger plunger and plunger spring provide the tension to reset the trigger and disconnector. Second, attempting to use Mark II replacement parts may work in your pistol, depending on which frame you have (A54 or A100). If your pistol is a 1972 model, or later, you can use a Mark II hammer pivot pin and Mark II style grips, with the cut-out for the head of the pivot pin. An A54 frame does not have the same grip screw pattern and will not allow the use of Mark II style grips.

Sounds as if someone, at one time, tried to force the mainspring housing closed and the results were the bent pins. The frame crosspin, in the mainspring well, is not critical and can be tapped back into straightness without any difficulties. It is only there to provide a anchor stopping point for the sear spring. The hammer pivot pins are the same diameter between the generation models and one could use a later version to replace an earlier, no- head pivot pin. Mark I generation pistols use the grips to hold the straight shafted hammer pivot pin in place. If your pistol is an A54 version you could carefully cut the head off of a later pivot pin, as long as you maintain the original overall length of the pin, and carefully cut it to prevent over heating and possible loss of temper to the metal.

Next, I would detail disassemble and clean all the components. Pay particular attention to the top of the trigger and the trigger plunger and spring. Remove these components and thoroughly clean out the trigger plunger hole, lots of residue is deposited here and can cause symptoms like you've described. Removing a Mark I generation trigger is not difficult, but there is an "E" clip on the left side of the trigger locking and holding the trigger pivot pin in place. You can use a scribe or Jewler's screwdriver to pry the clip off of the pin. Reinstalling the clip is not difficult but can take some patience as it can slip off the pin and drop inside the frame instead of locking onto the pin.

Here's a couple of images that may assist you with your repairs.

Hope this helps.

R,
Bullseye

 

[Pappy1911]

I bought a MKI a bit ago and am having a few issues....

If you lose/break the e-clip ( A-34-1 ), I can send you a few free ones.

 

[North country gal]

Yup, that split ring, A34-1 is a real bugger. I wouldn't mess with it unless you have no choice.

 

[dingode]

So I took my micrometer to the pins. Come to find out the shank of a 3/32 bit works great for a sear spring stop pin and a #22 bit shank works great as a hammer pivot pit. Length for both seems to be right around .670 The bits are made in the USA out of HSS and ground to size. Anyone see a future problem with using these as pins?

I can now dry fire and keep the trigger pulled, rack the slide to cock the hammer again and when I release the trigger the disconnect resets as it should! YAY!!! I got to thinking last night after I said the sear wasn't engaging the hammer. If I were to wiggle the trigger forward there would be a click and then it would fire. That meant the hammer was cocked and the sear engaged, so it was the disconnect resetting/releasing that was making the clicking noise. So much more to learn about this gun.

I was able to cut the small bit down by grinding a groove and snapping off the rest of the bit. I tried it on the larger bit, but it bent rather than snapped, so I'll have to cut it tomorrow at work where I have the proper tools.

I haven't measured the sear pivot pin, but I have a spring kit on order and I'll measure that and hopefully find a suitable drill bit to use as a pin if the need arises.

I haven't had to mess with the trigger pivot pin yet, but we mess with those stupid little e-clips at work and I have a tool that will at least make putting it back on easier. If anyone is interested I'll try getting info on the tool and post it here.

 

[Bullseye]

If I recall correctly, the size of the "E" Clip is 1/8". You measure the inner diameter, between the prongs for the proper clip size.

FWIW, I don't have any issues removing these in just a few seconds with a hooked scribe or an Jewelers screwdriver - done hundreds of these over the years. Re-installation is nearly the same with a simple pair of duck-billed pliers. Your actual experience may vary but I'm a professional and used to working without a net.

R,
Bullseye

 

[Iowegan]

dingode, I have made several hammer pivot pins for Standards and MK Is from 5/32" drill rod. A shank from an inexpensive drill bit will work just perfect. As you noted, a 3/32" drill bit shank will work for sear spring pin.

Normally these pins last forever but if the pistol is reassembled incorrectly, both of these pins can get bent.

 

[dingode]

I'm guessing that's how the originals got bent. It's getting easier to put it back together now that I have done it a few times. The first time took me 45 minutes! Now I can do it in a minute or two.

I think I'm going to make a few extra pins and keep them in the case with the gun just in case I get lazy putting it back together and bend them again.

 

[dingode]

Well I shot it today and it shot AWESOME! Shooting plates at a club and I was nailing them, until the new hammer pin worked it's way out that is

I had MKII grips on it a guy gave me this morning and I hadn't had a chance to fill in the cut outs yet to retain the pins. I swapped over to my Sig mosquito.

Talk about going from a Cadillac to a Yugo. I'm only keeping the skeeter because it's light and small and I'm thinking the kids will be able to hold it easier when they start to shoot this fall. Other than that I'd dump it. Trigger is terrible and it's a jam master no matter what type of ammo is used.