Absolutely Perplexed with a MK II

[bobobooie]

Recently bought another MKII bull with a 4" brl. Added the Volq trigger and sear and a red dot. Was not satisfied with the trigger and decided to tear it back down and put in another disconnector that was not as worn.
The sear pin is loose and backed out causing the sear to fall out. No big deal.

Put it all back together. And my headache started...

The hammer would not go forward when trying to insert the mainspring housing to lock it all up. With downward pressure on top of the hammer it finally did release. The bolt pulls to the rear and cock the hammer. The trigger has no effect on the function. The gun will not fire The hammer will not fall when the gun is all together. I backed out all the screws on the Volq trigger and did it all again. Same thing.

I put the old disconnector back in, same thing. The trigger moves, but the hammer and sear stay connected. The disconnector moves a tad when the trigger is pulled, but the sear and hammer do not separate.The trigger is under the pressure of the return spring/plunger. I cannot get the hammer and sear to separate by using the trigger to do so.

I put everything down and will take a break. I have become frustrated. My Rugers have been apart many, many times. I have never had a problem with the assembly. Now I realize I really don't know how each part interacts. I have books and videos, but none of them have a checklist after every pin/part is installed. I have never needed it, but am totally at a loss now. Every part worked fine, now they don't???? I have the feeling I have messed up the assembly somehow.
Thanks in advance for any advice.
Paul

[bobobooie]

Took apart the Aristocrat rib gun and saw that the trigger pulls the disconnector which moves the sear away from the hammer.

The troubled gun does not do this. The trigger moves the disconnector, but has no effect on the sear. Arghhhhhhhhh!

[Bullseye]

Let me fill in a few of the blanks for you. The trigger moves the disconnector lever forward when pulled. The disconnector has a small tab on the bottom edge that slides in a groove on the right side of the sear. When the disconnector lever is aligned with the bolt, and the bolt is fully closed, the top of the disconnector is free to lift upward. This upward movement allows the disconnector tab, that small metal piece riding in the slot, to rise up and push against the back of the sear rotating it forward on the sear pivot pin. This forward rotation causes the sear face to slide out from underneath the hammer hook and the hammer releases to strike the firing pin. If the disconnector lever does not rise up two conditions could exist; one is that the trigger return spring and plunger in the top of the trigger are bound up, or that the disconnector lever may be hanging up on the edge of the hammer bushing which prevents the lever from moving upward.

If you have free movement on the trigger return plunger, and the disconnector lever springs upward freely with the receiver off and the mainspring housing installed, then you may have some interference from the thumb safety hook on the top of the sear.

You can see an animation of the trigger, disconnector, sear, and hammer here- http://www.guntalk-online.com/images/mk2triggerani.gif

I hope this helps some.

R,
Bullseye

[bobobooie]

I think your explanation will help. The small tab on the bottom of the disconnector was explained really well. I'll go at it again this afternoon. I had been checking without the mainspring housing installed, utilizing the small pressure the return spring provides as I work the trigger rearward.
The return spring and plunger are not bound up and their hole was polished with 600grt wet/dry sand paper, but not deepened.
I'll start over and utilize the mainspring housing when I check.
Thank you for your excellent explanation.
P

[bobobooie]

Could not wait and went back to the bench. Used another MKII frame for comparison as I put the guts back into the trouble frame.

Without the mainspring into the frame the two frames act the same. The hammer can be moved forward when the trigger is pulled. I can see the sear rotate.
When I insert the mainsprings into the frames is where the trouble starts.

The good frame acts normal and the trigger moves the disconnector, the sear rotates and the hammer springs forward.

On the troubled frame the trigger moves, the disconnector moves, and nothing else happens. The sear stays stationary.

From what you mentioned earlier, is it the safety hook holding up any movement of the sear? Without the mainspring housing in, all appears fine. Under spring tension the sear is not responding to trigger movement.
Thank you again for your time and patience.
P

[blue68f100]

With the barrel on, can the dissconnector be moved using a punch through the ejection port? It should be able to pop up freely when you depress it. If not it may be binding up on the side of the frame or not centered in the bolt slot. I have seen these (disconnectors) bent and they can cause you a lot of problems.

[bobobooie]

With the barrel on, can the dissconnector be moved using a punch through the ejection port? It should be able to pop up freely when you depress it. If not it may be binding up on the side of the frame or not centered in the bolt slot. I have seen these (disconnectors) bent and they can cause you a lot of problems.

I'd rather poke it with the barrel/receiver off for the time being. I'll play with the disconnector tonight with the mainspring housing in place. For some reason, once the assembly is under pressure from the mainspring, the trigger via disconnector won't trip the sear from the hammer.
When I was trying it with the barrel/receiver on, the bolt would cycle to the rear cocking the hammer. Then it would not fire and I was having to pop pins to get it apart again. Once it functions in the frame, I'll button it all up and see what happens then.
Keep the ideas coming though, and thank you.
Paul

[bobobooie]

Well duhhhhhh! I still do not understand the why???? But, the gun is up and running with the crispest trigger pull yet.

I decided to start replacing parts as I have small parts bins with extras I have taken off other Rugers. I decided the first order was to try another hammer. It was then I noticed the hammer in the gun had two holes in it, not one hole just for the bushing. Volq? I think so.
I put in a factory hammer and VOILA! I adjusted the pre and over travel and so happy with the crisp trigger.

I may never know what it was about the hammer and the new Volq sear. I had problems a couple years ago with a hammer from Volq and this time I only ordered their sear and tried to mate it to the hammer in the gun.

The sear that was in the gun is gold colored. I researched it and found some member of this forum asked about one back in 2010. It is not heat related. The entire thing is maybe coated with slickness??? It mated up to the hammer I took out, so I marked them and will leave them as a set .

I would love to know the why this hammer caused this; the mechanics of it.
Thanks for listening and for the advice.
Paul

[Bullseye]

Difficult to say without being able to inspect the hammer. It could be that the engagement angles of the hammer and sear are not compatible and caused the sear to get stuck under the hammer hook. When you pull the trigger the hammer does rotate backwards slightly just before let off as it has a slightly negative engagement angle. Under mainspring pressure, the negative angle of the hammer may be too great for the sear to overcome and this is why it is sticking. However without the additional pressure of the mainspring the sear can move under the hammer when it is not installed. These are the best theoretical reasons I can describe without seeing the actual components.

R,
Bullseye