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My MKIII seems to function fine on CCI standard, but when I practice with Federal bulk I get lots of failures-to-fire.

I used to ignore this, but after examining some brass I see that the strikes are lighter than they were a few months ago. I can see the difference with old brass I kept around for dry firing. The latest pin prints are not as deep and slightly higher (further from the center of the brass).

I shot through 100 rounds of CCI standard today with no problem, but about 85-90% of the federal goes bang.

I have been dryfiring by removing the firing pin every week, putting it back in on the weekend. I noticed the firing pin return spring is slightly curved, but I think the pin is seated ok. The firing pin does have a tiny bit of "play" in the track.

The chamber face is clean. I almost never clean inside the chamber but am wondering if this is a sign I should?

Is this a symptom of something that needs to be addressed?

melchloboo wrote:Is this a symptom of something that needs to be addressed?

my $0.22-worth... my first thought is try some "other" ammo to break the tie.

CCI has ALWAYS been my reference ammo. dependable stuff.
the "play" may not be anything at all. the firing-pin hangs-loose
and as it runs forward gets "focused" on where to strike...
since you regularly remove it for Dry-Fires, I would assume even
minimal cleaning/lube would be more than many firing-pins receive.

Do you have a 2nd MK2 to swap-springs?
...but... the spring would have the same tension for CCI-vs-FedBulk...

thus... I suspect some thicker-brass... on some runs of the Fed ammo.
let me/us know what (else) you detect...
-- toy

Another thing to check is your overtravel adjustment. You want the hammer hook to have full clearance and not strike the sear face after release, because that will drain off some of the hammer's striking energy. You might ask why would that make any difference? The answer is the type of brass for each brand of ammo. Some brands are thicker walled than others and the amount of hammer energy needed to dent the thicker brass is higher. Your hammer is striking at the same amount of force for all brands but the thinner brass rims are detonating more consistently.

R,
Bullseye

Some follow up: I shot a match today, 90 rounds of cci standard. I had one fail to go bang and had to shoot an alibi string. I have never had cci standard fail to go bang, nor so many of the cheaper bulk ammo fail as of late. I tried some federal bulk and remington bulk and 2/5 and 3/5 failed to go. Although I shoot matches with the pistol I like to practice on the cheaper stuff. (there is some benefit to the occasional dud in practice, it was nice to see that I had zero anticipation when the shot failed to bang). As I say, I used to save brass and use it to dryfire, so I got to know my pin's "print" pretty well. Its just not the same anymore. Its higher and not as deep.

I heard different things from club members:
1. One MKIII owner said he once took out the firing pin assembly to clean it, and afterwards was having the same problem. He said he sent it back to ruger and they said "they've been having this problem" and they did some things to it (he's not sure what) and sent it back and its fine. They sent him before and after brass to show that the prints were different before and after their work.
2. Another suggested that the hammer striking the bolt with no firing pin may have damaged the hammer or bolt or both, that my dry firing technique (25-30 a day) with the firing pin removed is the cause.

Bullseye-the over travel screw--you mean the one in the middle of the of the VQ trigger that is in contact with the finger? I originally blue loctited it and had several thousand rounds since installing it, but I suppose it possibly could have shifted. But I feel the problem is not isolated to depth of the strike, that the pin is slightly further from center, although maybe this is an illusion created by the lighter strike. But this is easy to test on empty brass....do I want more or less over travel? I had actually set mine to give a little give after break, I was concerned that it might not release the hammer consistently if I tried to make it "perfect". I can't say I completely follow your idea, as it seems to me once the hammer is released its released, but I'll give it a try just let me know if it should be more or less.

You may need a little more overtravel - screw backed out. The way to check is by first removing the receiver then manually catching the hammer with your left thumb while releasing it by activating the trigger with your right index finger and holding the trigger against the rear of the trigger guard. Once the hammer is released, you slowly let it move to the fully up position all while still holding the trigger rearward. The hammer should not drag on anything as it moves to the fully released position. If the hammer feels like it is dragging on the top of the sear then you need to back out the overtravel screw.

Hope this helps.

R,
Bullseye

Thanks, I think I understand now, I will give it a try. Probably wouldn't hurt to do a detail strip and clean everything...I had assumed this was a chamber or pin problem but maybe the culprit lies elsewhere...

If you can manually push the firing pin, and it extends and retracts cleanly without hanging up, then the pin is not causing the problem. That bolt is very hard material and peening it from the hammer is not an easy thing to do. If you could peen it with the firing pin removed, the same actions would be occurring when the pin is installed. The firing pin does very little to absorb the hammer's impact. The hammer's force is dissipated on the rear of the bolt all the time and everyone would be having firing pin troubles if the firing pin track could peen from high use.

R,
Bullseye

Update:
1. I removed receiver and without the bolt stop, put in an empty magazine, pulled the trigger and manually brought the hammer forward. It did seem to push/nudge the sear forward as it went upward, then again as I retracted it. I did this a few times and it consistently nudged it...although it didn't really feel like much, I could see the sear move.
2. I then tried it with the bolt stop in place but didn't resist the hammer as it came forward, it went too far forward where I felt I couldn't recock it with out giving too much force, so I had to take the gun apart and that ended the experiment.

I was about to put the gun back together then noticed the hammer is showing some wear:


The area where the firing pin has made a mark is not indented as it looks in the picture, its more of a polish(can't be felt with finger or fingernail). But that nick and line across are definitely there and can be felt as I run my finger over them. I think they are caused by some rough edges at the base of the bolt:


I kind of doubt that these have anything to do with the problem, if anything the dent allows the hammer to hit the pin more squarely than it would otherwise. However, it makes me wonder if the hammer is striking square or not, or at an upwards angle that is pushing the top of the pin into the bolt return spring? I kind of doubt that.

Anyway I wanted to run these by you before I put the gun back together. And to confirm that my way of checking hammer/sear clearance is ok, i.e. without the bolt stop pin in and just manually rotating the hammer forward and back while I have the trigger pulled. Because in your description it sounded like you meant having the bolt stop in, but I don't think that changes anything?

Lastly I would say the aside from nudging the sear the hammer was not swinging very loosely, there seemed to be slight friction but everything is clean.

That slight friction and nudging is the part were the hammer is loosing energy on the sear face. Back out your overtravel screw until you don't feel (or see) any dragging on the sear and you should be good.

R,
Bullseye

Bullseye-
I am not saying you were wrong, but I believe I found the cause. I believe it was the pin that holds the hammer strut (the little thing that swings on the hammer).

I started turning the overtravel screw as you described, and after a full turn I realized that on a light trigger pull the sear will always get rubbed slightly, unless the trigger is fully pulled back. The loctite was still binding, so I doubt the screw could have shifted that much.

What I really noticed was that the hammer was rubbing something. Eventually I saw that the head of the pin described above was cocked slightly on one side, as if the pin was inserted at an odd angle. I took the hammer out, squeezed on the pin with a pliers and now it sits more even and the hammer swings noticeably more freely. I was happy but mad at myself for not taking a picture first.

In other words, I think the sear energy loss is real, but not enough to cause the problem. The loose hammer strut pin was causing far more resistance as it rubs against the safety lever.

I'm going to reassemble the gun and see what happens. I'm debating whether to a) file the head of that pin down a little more, or alternatively the safety lever b) just put a dab of oil on the head, c) send the hammer back to VQ and hope they take my word for it that there was a problem, d) forget about it if all is well.

I'll try a dab of oil and see how my strikes look.

(P.S. and totally off topic, when you drop any small part of a gun it will defy all laws of physics and bounce to an unlikely location in your workshop that will take you at least a half hour to find it)

Update on empty brass:
1. The strikes with the VQ hammer looked a little better, definitely better than the strikes on the rounds that failed, but not as good as old brass. How free does the hammer swing? If the hammer is upright, should it fall back into place on its own (with the trigger pulled back)? Mine doesn't.

2. So I put the old factory hammer back, I notice a few things. First its pin head is much more flush, doesn't spin so easily, and thinner. I realize maybe the VQ hammer is narrower to account for this, I don't have calipers to check though. Almost imperceptibly, the factory hammer does swing a little easier, but still doesn't fall back into place on its own, and requires a hard flick to get up like the VQ hammer.

3. But most of all the strikes with the factory hammer look much better. They are deeper, particularly on the bottom edge of the pin (closest to the center of the brass) the line is more defined and deeper. The strikes with the old hammer are almost as good as the old brass. Maybe this is also attributable to the factory hammer being heavier.

So what now? I think the factory hammer is going to be more reliable, and I don't recall why I got the VQ hammer other than it was part of the kit. I guess I will weigh the trigger pull again and make sure its not heavier.

I am somewhat convinced though that both hammers would greatly benefit from having the face of the safety lever reduced with a file because both hammers have their strut pin head rub against it. Unless that friction is necessary to keep the hammer stable and lined up? I notice that both pin heads have grooves which is maybe intended to increase friction?

I guess in sum questions are:
1. What are advantage/disadvantage of VQ hammer?
2. Should my hammer be swinging freer than what I have described?
3. Would creating space between the hammer strut pin head and the safety lever be worth a try?

Update 2:
Weighed the trigger, now its somewhere between 2# and 2.25#, probably .25# lighter than my post a while back with the VQ hammer:
http://www.guntalk-online.com/forum/vie ... highlight=

So more and more the factory hammer looks like the keeper.

One more question, is it safe to go back to the factory hammer and dry fire without the firing pin, i.e. is the factory hammer able to take that un-cushioned beating?

(p.s. to address the marks I pointed out earlier on the hammer face, the old factory hammer has the same marks so I guess its normal)

If the overtravel stop adjustment didn't fix the problem we would have progressed down the line to other symptoms that could cause the same type of failure. The rivet head on some hammers does stick out too far and drags on the thumb safety lever. When this happens I usually use a file then a stone to dress down the rivet head on these and make it a little thinner. You can check for excessive hammer drag by marking the rivet head with a sharpie style permanent magic marker and then dry firing it a few times. Remove the hammer and look for drag marks that have scraped off the marker ink.

You will be fine with your practice routine and the factory hammer.

I have recommended for years to just use a OEM hammer with the VQ sear for the trigger upgrade. I have not seen a marked difference in the engagement angles to justify purchasing the VQ hammer. The VQ hammer is lighter than the factory original and has been known to cause light firing pin strikes in some pistols.

A hammer moving freely under gravity does not act the same as on under the tension of the mainspring. It should move fully rearward on its own but is the hammer strut getting caught on the crosspin?

Hope this helps.

R,
Bullseye

Thanks. I don't think the strut is getting caught. For example, if I put the hammer straight up, keep the trigger held and then hold the gun pointing up, the hammer just sits there. It needs to be pushed all the way back and will stick all the way. In this position the strut is just hanging free.

I didn't do the magic marker test, but I oiled just that rivet head and there is oil on the safety lever as well now. I'm pretty sure I can see them rubbing.

Do you think there would be any difference between filing the rivet versus filing the safety lever? Only because I don't have polishing stones, and I'd be less worried about taking too much off and could get it done by just by hitting the safety lever with the dremel to grind off some clearance for the rivet head.

Or, if I can get to the range tomorrow if all seems well I may just leave it be. The strike mark looks like cci should now fire every time, I think the cheap walmart ammo should fire better now too. I have an 1800 match on Sunday, I want to figure things out before Saturday...bad juju to play with things the night before a match...

A new hammer is much easier to get if something goes wrong than a thumb safety lever. But either way, if you remove some material the result will be the same. You likely wouldn't have to remove very much rivet head material, and since it has the smaller surface area would be the best place to shave off metal. If this safety lever is blue then you'd have to re blue it. Hammer rivets don't have that concern.

R,
Bullseye