Ruger Mark 3 Light Primer Strikes

[204dude]

Hello All,

I have been reading for a while but this is my first post.

I am having light primer strikes across several brands of 22s.

I have had problems with American Eagle, Federal 550, Federal Champion and remington golden bullet.

The gun has probably about 5000 or so rounds. I have not counted.

I honestly can't remember exactly when the problem started. It has been happening for quite some time and I just attributed it to cheap bulk ammo but it is too frequent to be the ammo's fault. Also I have saved these duds and fired them in another gun and they go bang so it is not always the ammo's fault.

I installed a volquartzen sear, removed the magazine safety and used a mark 2 hammer bushing as I read in another post. This greatly enhanced the trigger pull. I am very happy with the trigger.

I can't help but think that my modifications have caused this problem.

To be continued.

[204dude]

I have read on this forum and others about the possible causes and still can't figure this out.



As you can see in the photo my hammer and sear are not engaging evenly. You can see rub marks as indicated by the arrow. I am not sure what is causing this other than something is out of line and robbing the hammer of inertia.

I have been testing this lately with no success. I thought dirty chamber. No that's not it. I have stripped the gun and given a thorough cleaning including firing pin channel.

I did find a small burr in the firing pin on the right side just under where it strikes the brass. I polished this smooth and it still gives light strikes.

Today I cleaned the entire gun thoroughly and completely removed the loaded chamber indicator.

To be continued.

[204dude]

I am sure the root of my problem is the misalighnment of the sear and hammer but I am not sure how to address this so I wanted to eliminate other obstacles first.

Any suggestions are appreciated.

Thanks

[Bullseye]

The rubbing on the hammer face is likely the source of your light strikes. The sear face is not clearing the hammer and friction is reducing hammer speed and inertia.

From the picture it appears that the sear is touching the hammer bushing on the right side and this is tilting it. Is that the case? How is the clearance on the left side where the thumb safety hook is located?

It also looks to me like your overtravel stop may be set too close and that could cause the rubbing on the hammer by the sear face.

While the picture is clear, it is tough to see all the particulars without some shots at a slight angle for the hammer and sear engagements.

R,
Bullseye

[204dude]

Thanks for your response Bullseye.

You are correct when you say "the sear is touching the hammer bushing on the right side." The "clearance on the left side where the thumb safety hook" is ample. There is no rubbing.

You mentioned the "overtravel stop" This has a stock Ruger trigger. The only thing I did was eliminate the magazine disconnect, install a Mark 2 bushing and the Volquartzen sear. I was under the impression (mabee incorrectly) that the overtravel stop was only on aftermarket triggers. Am I wrong? If so where is it located?

I did not use a spacer to take up the space where the magazine disconnect was and I believe that may be the cause of the hammer and sear being uneven. Today I got a brass washer to act as a spacer. It seems that the hammer and sear are more even now.

I will try this out soon and report back.






Thanks

[Bullseye]

The first thing I noticed was the addition of the spacer washer. That is a regular Ruger Mark II bushing isn't it? At first I thought you had a Clark Oversized hammer bushing installed but now I can see by the loose fit of the bushing it's a factory one. Nice pics by the way.

The regular OEM trigger has an overtravel stop in it too. The factory trigger has it on the front face above the trigger pivot pin. You have to remove the trigger up slightly to see it. The allen screw is right in front, near where the disconnector pin mounts to the trigger. But if yours is like most, that screw is not even adjusted and is fully recessed inside the trigger body. When you squeeze the trigger all the way does the sear fully swing out and clear the hammer hook. Does this clearance hold throughout the full swing of the hammer upwards? If it does now then your brass spacer may be the answer to the rubbing problem. Once the extra hammer friction is eliminated your light strikes will disappear too.


R,
Bullseye

[204dude]

Bullseye,

You are correct it is a regular factory Mark 2 hammer bushing. As far as I can tell the sear is fully clearing the hammer hook and the clearance is holding throughout as you stated.

I am more confident that this has fixed the problem. I won't know until testing; probably this weekend.

Thanks for the compliment on the photos.

After carefully looking I NOW see the overtravel screw. I have never touched this so unless it backed out it is factory adjusted.

I will give a report soon.

Thanks for your help.

[Bullseye]

Take a sharpie permanent marker and color the area above the hammer hook where the parts were rubbing. If there is any more contact, the marker will be worn away indicating there's still a clearance issue, or it will indicate there's not an issue if the marker ink is untouched.

R,
Bullseye

[204dude]

Thanks Bullseye.

I will mark the hammer and test it out tommorrow. I will keep you posted.

[204dude]

I fired about 200 rounds thru the mark 3 this weekend. I am still having light primer strikes but not until about the 150 round mark. It happened with 2 different magazines. I marked the hammer above the hammer step with marker and there does not appear to be any more rubbing.
I noticed something I overlooked before. The "duds" have an indentation the exact size of the feed ramp directly in line with the firing pin ding. I did not see this before.
I now suspect the cartridges are hitting the feed ramp at an angle that does not allow them to chamber smoothly. Like I said this did not occur until about 150 rounds. so I am not sure how to proceed from here.

Any advice is appreciated.

Thanks

[Bullseye]

Are these dents on top of the round? Or are they on the bottom side?

R,
Bullseye

[204dude]

Bullseye,

The dents are on the top of the round directly in line with the firing pin strike which as you know occurs on the top of the round.

[Bullseye]

I didn't notice that reference in your earlier post about being in line with the firing pin dent. I would expect a feed ramp scrape on the bottom side of the round. Yours sounds more like a magazine timing error or a extractor claw catching the case rim. If the mag's feed lips release the case too late the cartridge nose will be forced upward into the top of the chamber mouth. A similar circumstance would occur if the case rim cannot slide underneath the extractor hook during case insertion.

R,
Bullseye

[204dude]

Bullseye,

Thanks for the reply. I think I will order the vq extractor and see if that helps. If that does not solve the problem would you suggest the magazine tweak where you round off the sharp edges where the cartridge is released?
I am hesitant to do this but I could try on just one mag and see if it helps providing the vq extractor does not solve the problem.

[Bullseye]

That is a possibility if the extractor doesn't solve the problem. You're using a good strategy - just do one thing at a time. That way you can determine what solved the light strike problem.

R,
Bullseye