Interesting malf. in MK2 Gov. tonight!


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model 649
November 23, 2006, 12:03 AM
I had an interesting malfunction at the pin matches this evening. I was running my .22lr (Mark 2 Gov.). I heard what sounded like the gun "doubled" and saw it was jammed and smoking quite a bit. There was an empty case lodged above a half-chambered round, against the roof of the receiver, pointed out of the ejector port(like a stovepipe). Apparently, the empty case was fired out of battery(though there is no strike mark on the base). The case ruptured but was still able to get the bullet out of the barrel(thankfully)and mostly cycle the action. I am curious how the round fired at all, let alone out of battery. The round is a Federal Game-Shok 40 gr. I have been using these since the middle of last summer with no trouble til now. The pistol appears undamaged and I completed the match without further stoppages. Any ideas? Here's some pix of the offending case for you all to puzzle on.
Josh

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Dr.Rob
November 23, 2006, 12:30 AM
I'd contact Federal and Ruger with the pics... that's a new one to me.

Looks like an overloaded case.

Bullseye57
November 23, 2006, 01:06 AM
Your cartridge fired partially out of battery. Looks to me like there's a firing pin hit just above the "F" but dimple has been mostly shape pressed out by the force of the detonation against the bolt face. This is a condition that can happen if the cartridge is mostly seated in the chamber but about 1/8th inch of the case is still out of the chamber. Try holding the bolt back about that much and pulling the trigger and you'll see the hammer will drop. Pull the bolt back a little farther and the hammer will not drop because the disconnector lever will disengage the sear from the trigger. The amount of room the disconnector will engage the sear varies from pistol to pistol but about 1/8 the inch is about the norm. Ideally no gap is desired but very few Ruger pistols actually meet this tolerance. You got a double case feed because most of the cartridge's energy was expended by the case rupture instead of normally pushing the bolt rearward when fully chambered. Your pistol probably looked like this one when you first noticed it, but of course the rear of the case was ruptured when you looked further at it.

http://www.guntalk-online.com/images/hungcase.JPG

This condition can happen if the chamber is dirty or lead fouled near the barrel's lands. Give the chamber a good scrubbing with a copper bore brush and some Hoppes #9. If there's evidence of heavy leading then consider purchasing a Lewis Lead remover from Brownells. Those brass screens really pull out the lead and your pistol will be operating normally in no time. Stay away from cheap ammo like Remington Thunderbolts to keep the leading down to a minimum. I realize that this was a Federal cartridge but the lead could have built up from shooting poorer grade ammo in earlier sessions or by rapidly shooting ammo and the barrel heats up considerably. This situation has happend in the past and your's was much easier than this one where the case head separated, leaving a large part of the case in the chamber.

http://guntalk-online.com/images/case_sep.JPG

Or where the bullet is lodged in the barrel and a second round is fired damaging the barrel beyond repair.

Hope this helps.

R,
Bullseye

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JohnKSa
November 23, 2006, 02:18 AM
Your cartridge fired partially out of battery.That's what it looks like to me too. Something hit the rim with enough force to fire the round before the bolt was all the way closed.

It could have been:

Fouling or a small foreign object jammed the firing pin in the forward position allowing it to fire the round before it was fully chambered.

The firing pin is broken and sometimes protrudes too far forward.

The gun fired slightly out of battery due to fouling in the chamber that prevented the round from fully chambering.

I'd strip the gun and clean the chamber and the bolt/firing pin area very carefully. Inspect the firing pin and make sure that it moves freely.

model 649
November 23, 2006, 11:13 AM
Thank you for looking guys. Yup, the chamber is dirty, the barrel ahead of the chamber looks good, though, as far as leading goes. The firing pin is in one piece as well (thanks for the tip). This happened around the 150 round mark since the last scrubbing. The pistol will indeed drop the hammer out of battery though not quite to an eighth inch.(Likely the exact distance the bulge in the case is thick..) Any thoughts/ideas about adding a bit of metal to the top of the disconnect/sear-release bar to shrink the distance the pistol can fire out of battery? I'm seeing a polished area where the bolt rides over the bar that might be helping this distance to increase. I don't have a new part to compare it with to see how far along it is really. If the "up to an eighth inch" condition is normal I'm thinking it could be improved. Thanks again,
Josh

Bullseye57
November 23, 2006, 11:53 AM
That distance is well within the factory limit, I wouldn't mess with the disconnector lever or try to change the timing. If there's any mistake you will not be able to get this part, it is a factory only replacement.

Your dirty chamber is the likely culprit, give it a real good scrubbing and the problem should go away. If this is a new pistol then the chamber may be a little rough and that can amplify the seating problem. I usually run a .22 match chamber reamer through any tight chambers to smooth them out but not everyone has this tool laying around and available.

Hope this helps.

R,
Bullseye


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JohnKSa
November 24, 2006, 01:25 AM
Was thinking about this and remembered a problem I had a long time ago with a MkII...

Is your feedramp rough? That can ding up the bullet enough in some cases that it will cause chambering issues and increase fouling in the leade. If your feedramp isn't smooth, fixing that might take care of the problem.

I wouldn't really expect a MkII to start jamming after only 150 rounds. I clean mine every few years... :o

model 649
November 24, 2006, 11:30 AM
I wouldn't say the ramp is rough, but, there is a definite "step" at the top, below the chamber throat. I have seen this on other Mark 2's that function well over 150 rounds. The only time I observe damage to a bullet as a round chambered was with hollow-points, and it appeard that the top of the chamber mouth was contacting them. Round-nosed bullets chamber cleanly. I have wondered wether breaking the edge(and all the other sharp edges) that surrounds the chamber throat would help. That is an area that crud builds up in my observation( the factory didn't clean up the small raised "burr" of an edge at the chamber mouth). I hesitate to mess with the pistol too much as it functions very well if kept clean. Back to the disconnector thoughts, The amount of metal worn off the leading corner (where the bolt surface contacts it) doesn't seem to matter enough to replace it. The sear doesn't disconnect until there is a more substantial movement by the bolt. I still don't like the amount of wear there though. The edges are slightly rolled off it(so now it has a slightly wider contact surface, which might be beneficial) and it has a definite "dip" where there was once a radius. I keep it lubed with moly grease to minimize additional wear, but it appears that the former owner didn't pay much attention to this area. On the other hand, might this be getting exaggerated by using high-velocity ammo? I replaced every spring right after I got the pistol, including the recoil spring with a wolf "extra power" in anticipation of using the 40 gr. rounds for pin-top competition. So what say y'all? Should I start breaking edges and polishing? Or, should I just keep it the way it is, knowing I can't let it stay dirty match-to-match? Thanks for all the input thus far. I really appreciate having access to more experienced brains.
Josh

wally
November 24, 2006, 11:50 AM
These case head blowouts are not too uncommon with my AMT lightning MkII clone with the Remington "Golden Bullet" bulk pack ammo, although misfires are much more common. I got a new recoil spring assembly and hammer spring which has greatly reduced the frequency of both, but basically I just quit shooitng the Remington Golden Bullet ammo in it. Its fine in my other guns, although the misfire freqency overall seems a bit higher than with other brands of cheap ammo.

If it happens with increasing frequency and other brands of ammo I'd send the gun back to Ruger. It shouldn't fire out of battery period, but if its rare I doubt there is anything anyone can do about it untill it becomes reproducible. They might just replace the bolt and hope the problem goes away to keep you happy, so I'd send it back if this failure worries you.

But ther real lesson here is this is why everyone at ther range needs safety glasses on 100% of the time *anyone* is shooting.

Obviously, any round with abnormal report when fired requires that shooting be stopped immediately and the bore checked to prevent possible disaster!

--wally.

JohnKSa
November 24, 2006, 05:20 PM
Are you seeing any bullet material being rasped off by the ramp or accumulating at the step? If so, maybe some smoothing is in order.

Try chambering a round (at the range would be safest) and then carefully ejecting it onto a rag without firing it. Is the bullet dinged, scraped or bent?

If you don't find any problems then I'd be real tempted write this off as a freak occurrence until/unless it happens again. I'd also be tempted to put a stock weight spring back in.

I really can't get comfortable with the idea that you need to clean a MkII every 150 rounds to keep it working. That's never been my experience, to say the least!

model 649
November 24, 2006, 06:04 PM
The only bullets that get beat up are hollow-points. They seem to get hit by the top of the chamber mouth as they enter. The round-nose types are o.k.(no damage/dings/shaving). The whole area back of chamber gets pretty dirty with whatever ammo I have tried. The chamber and bore do well. I can generally only clean the area rear of the chamber to keep it running well. There is quite alot of mucky grime all over the inside of the pistol by about 150 rounds, and the malfunctions are usually FTF's where the gun doesn't fire. This one was a first-timer. It occured early in the fourth match, so about 150 rounds from a complete cleaning. This is my only Mark 2 so I can't really say how many rounds it should go between cleanings. As much muck as comes out of the pistol, I figure it can't go too much more. I use mainly CCI or Federal with some Winchesters and Wolfs in the mix. Rems are the filthiest so I avoid them. The reason I went to the heavier recoil spring is that it was recommended when using high-velocity ammo. The pistol still cycles the standard velocity ammo reliably, so, I don't know how much "extra power" the Wolff spring really has over the standard unit. This pistol's performance has been good as long as it gets cleaned out sooner than later since I've been shooting it. Parts haven't made any difference so far. Do you think removing or breaking the edge around the chamber mouth will have any effect or is the sharp edge pretty normal for these guns?
Josh

JohnKSa
November 24, 2006, 07:39 PM
The step you describe is there on my current MkII so I don't think you need to remove it. I'm not sure why the HP rounds are bouncing off the top back edge of the chamber, I've never had that problem with any of my MkIIs that I know of.

I can tell you that if you're having to clean every 150 rounds to avoid malfunctions that something is almost certainly wrong with the gun or the ammo you're using. Back when I was shooting a lot, I used to clean every 500 rounds, and that was really just 'because', not a result of malfunctions or problems. I don't clean that often these days and still don't have any malfunctions.

winchester62
November 24, 2006, 09:55 PM
I sent a MKII back for this very reason a number of years ago. It came back exactly the same - but dirty. Turns out *every* MKII I've owned fires out of battery. Keeping the chamber relatively clean keeps this from happening. It won't hurt the gun - just try not to catch a stray shard in the eye!;) :D

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