Strange jam with a Mark I???????

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msinc

Bearcat
Joined
Jul 16, 2008
Messages
31
Location
Maryland
Hello, I have an older Mark I that was brought to me because it jams. I test fire it and sure enough the cartridge tries to climb up the feed ramp and stops the bolt when you try to load the first round from the magazine. If I try to hand load the first round it will climb the ramp and lock up on the second round. Cannot even fire two consecutive rounds out of this thing. Initially I polished the bolt face and the feed ramp, no change.
I clean the gun real good and get a new magazine. Same thing. I see all the posts on the web about rounding the sharp corners and try that...zero change. I adjust the feed lips and give them a good polish and that solves the climbing up the ramp thing, but now that i can actually load and fire the gun the bolt ends up on top of the "next" round and jams it that way. It is as if the bolt is short stroking. This doesn't make sense because the gun will positively eject the fired round. Now I am thinking some kind of timing issue. At this point you can load a magazine and hand cycle the action flawlessly. It loads, extracts, ejects and reloads no problem...just not when you fire it.
I take the gun completely down looking for a problem and find one. I really thought I had it...the magazine button was dragging on the inside surface of the right side walnut grip panel. I give it plenty of relief and head out to shoot it just knowing it will work...nope, same thing. I know that the bolt is very fast on the Mark pistols. What seems like a short stroke cant be because the fired round gets ejected perfectly, but for some reason the bolt ends up over top the next round and wedges between the round when it tried to get up the feed ramp.
It cannot eject the fired round until the bolt is well behind the next round in the magazine, so it seems like the only way the bolt could get on top of the round instead of behind it is if there was a delay in the round coming up {again, I know the bolt on these things is very fast} or the magazine is sitting too low in the receiver. Doesn't seem like it is sitting too low because, again, it cycles fine and picks up every round when cycled by hand {way slower, back to the timing thing again.}
For what it's worth, the owner says it has been shot a lot, but nothing appears to be worn. There is moderate peening on the breech of the barrel by the bolt, but everything else looks fine for its age. This is an early one. This gun is whistle clean, and the bore is perfect. The new magazine feels like the spring is heavier or stronger than my pretty new Mark III Hunter and definitely heavier and harder to load by hand than the old magazine. Thanks in advance for any info!!!!! All replies are greatly appreciated.
 
Joined
Apr 5, 2004
Messages
2,791
Location
Granbury, TX. USA
I'd look into the ejector (not to be confused with the extractor)

http://www.brownells.com/handgun-parts/action-parts/ejector-parts/ejectors/ejector-ss-sku780000346-11320-27974.aspx?cm_mmc=cse-_-Itwine-_-shoppingpla-_-Ejector%2C%20Ss&gdffi=4c10f1ff40354714b834b0032f76348a&gdfms=7DB87C98AF384661AD12F121A8A7409C

I've seen this exact same situation you described, and the ejector was "off"... replacing it resolved the issue.
 

PriseDeFer

Single-Sixer
Joined
Apr 22, 2014
Messages
450
I have a Mk I and have had first round hang ups. Problem turned out to be how I loaded that top round (last one inserted into the magazine). It can seat two ways, one way it sticks up higher than the other way and the sticks up way is the bad one. When the top round lays parallel with the others in the magazine all is well.
 

msinc

Bearcat
Joined
Jul 16, 2008
Messages
31
Location
Maryland
Thanks for the replies so far fellas...I am pretty sure the ejector is okay. The pistol ejects no problem whether I cycle it by hand, fast or slow, and when firing. It is there in place and does not appear broken or bent. I don't know what a new one would change if anything based on the appearance of the one that is there now. On the other hand it is not a very costly part so I just might go ahead and try it anyways.
I understand the first round thing...that is really what started this whole episode...but, the new magazine appears to have solved that problem. Before, I could not get past the first round for the jam against the feed ramp. Now, with the new mag I can hand cycle the action flawlessly...I just cant shoot the gun that way. To be clear, when shooting it will jam every round.
A gunsmith I know suggested that I try low power ammo. He is saying that there was no hi-speed or high powered ammo available when this gun was new and that since the bolt speed is so high anyway the bolt is closing sooner than the next round can get up into place. This sure sounds like exactly what is happening, but others on the web are saying that their Mark I will run with any ammo they feed it. A stronger action spring will just make the bolt close even faster. Thanks again.

Edit: I have to wonder what if anything different they did with the Mark III to shoot modern hi speed stuff...I have a Hunter model and it eats up any ammo I feed it, cheap, expensive, fast, slow...it likes it all. Over the years I have owned many Mark auto pistols and never had one jam, much less so consistently every shot. I feel like something should be jumping out at me, but it's not.
 

msinc

Bearcat
Joined
Jul 16, 2008
Messages
31
Location
Maryland
Well, I just got back from test firing this thing with Eley Target ammo...it shot flawlessly!!! Not a jam one for several magazines worth. I went back to the other hi speed ammo and got a jam every round.
This still begs the question...how does every one else's Mark I shoot any ammo {at least they claim theirs will} but this one will not??? Thanks again for the replies.
 

msinc

Bearcat
Joined
Jul 16, 2008
Messages
31
Location
Maryland
Well, that always seemed reasonable to me, but according to everything I have been taught or read a tighter spring causes the bolt to actually return faster. While there is no question that a tighter spring will slow the bolt down going back, it also makes it fly forward that much faster. The movement backwards to kick out the empty is not the problem...that could be doubled in speed and not really effect the loading of the chamber...it's the bolts return that is causing the problem.
I don't know how many thousands of rounds have been down the pipe on this pistol, but it looks like plenty and yet the spring feels about the same as my new Hunter Mark III. I also just realized I posted this entire thread in the wrong place. Thanks again for the replies.
 

jjas

Single-Sixer
Joined
Jul 15, 2011
Messages
268
While it may/may not be the recoil spring, it's a wear item on an older pistol that you said yourself has been shot quite a bit.

So for less than $10.00, why not try that?
 

msinc

Bearcat
Joined
Jul 16, 2008
Messages
31
Location
Maryland
Early on I did in fact swap out the recoil spring with the one out of my Mark pistol and it made no difference. Mine runs perfectly. I even put that one in my gun and it still shot fine.
I tried 6 different brand/types of ammo, but they were all hi-speed stuff. Not until I went to target ammo did this thing function properly. Turns out that the issue was the bolt speed. The early Mark I was not designed to operate with hi speed 22 long rifle ammo. Again, I have to wonder what the difference is or what they changed because I also have a Mark III that eats up everything I feed it.
 
Joined
Dec 25, 2007
Messages
10,030
Location
missouri
"Maybe the recoil spring is worn and you need a new spring, to compensate for the high speed ammo?"

The MK1 will function fine with HV ammo IF the spring/guide is in good condition. The comment about "the owner says it has been shot a lot," would be justification to replace the spring.
 

msinc

Bearcat
Joined
Jul 16, 2008
Messages
31
Location
Maryland
Mobuck said:
"Maybe the recoil spring is worn and you need a new spring, to compensate for the high speed ammo?"

The MK1 will function fine with HV ammo IF the spring/guide is in good condition. The comment about "the owner says it has been shot a lot," would be justification to replace the spring.

I understand what you are saying...but, if bolt speed is the problem and I know it is because target ammo cured the issue...then how would increasing bolt speed even more allow this gun to function with hi-speed ammo???? A stronger or new spring would allow the bolt to return even faster, how fast it flies back is not the issue because the gun functions perfectly up that point, it's the return of the bolt to battery that is when the jam occurs.
Again, when I swapped out the action spring assembly with a newer, known good functioning assembly it did nothing to correct the problem with this pistol. When I placed this pistols assembly in another gun it {that gun} worked OK.
 
Joined
Dec 25, 2007
Messages
10,030
Location
missouri
"A stronger or new spring would allow the bolt to return even faster,"

It's not so much how fast it closes but how much slower it opens. Overall cycle speed may actually be the same. If the problem is in fact the delay of the mag lifting the next round, the miniscule time between the retracting bolt clearing the base of the round, reversing direction, and traveling forward is critical.
There may be a combination of issues so the resolution may involve simply replacing parts until a functioning combination is found.

"What seems like a short stroke cant be because the fired round gets ejected perfectly,"
It's often possible for a semi-auto to eject a spent case w/o fully cycling. The AR15 platform has a whole list of this sort of malfunction. When shooting sub-sonic ammo, my 10-22 will often eject the fired case and catch the next round in the middle simply because the bolt is "almost but not quite" making a full cycle.
I'm a firm believer in keeping fresh springs in the MK and 22/45 pistols. We have several so I keep at least 2 new mainsprings on hand.
 

m657

Buckeye
Joined
Dec 1, 2007
Messages
1,419
Location
sunny Orygun territory
not a gunsmith, yet have seen this same thing on my Mk Is in the past.

Was told by a gunsmith this was the problem: HV slide opening on a worn spring is faster, throwing the timing off on the rest of the cycle.

SV slide opening on worn spring is 'normal'; closing speed for both HV & SV isn't the problem.

Decrease the 'window of slide retraction time' then slam close 'normally' means you shaved a little time off the feed-the-next-round.

New recoil spring fixed mine. Good luck on yours.
 

jackell

Bearcat
Joined
Sep 5, 2013
Messages
4
msinc said:
Well, that always seemed reasonable to me, but according to everything I have been taught or read a tighter spring causes the bolt to actually return faster. While there is no question that a tighter spring will slow the bolt down going back, it also makes it fly forward that much faster. The movement backwards to kick out the empty is not the problem...that could be doubled in speed and not really effect the loading of the chamber...it's the bolts return that is causing the problem.
I don't know how many thousands of rounds have been down the pipe on this pistol, but it looks like plenty and yet the spring feels about the same as my new Hunter Mark III. I also just realized I posted this entire thread in the wrong place. Thanks again for the replies.

I think what would happen with a stouter recoil spring is it would decelerate the bolt, which would make it take more time through it's cycle, instead of letting it whip all the way to the rear, rebound, and come flying forward aided by the rebounding effect. Making it take longer to cycle might aid in getting the round situated correctly at the top of the magazine after the previous round gets stripped off, that and an ultra clean magazine.
 

jackell

Bearcat
Joined
Sep 5, 2013
Messages
4
msinc said:
Mobuck said:
"Maybe the recoil spring is worn and you need a new spring, to compensate for the high speed ammo?"

The MK1 will function fine with HV ammo IF the spring/guide is in good condition. The comment about "the owner says it has been shot a lot," would be justification to replace the spring.

I understand what you are saying...but, if bolt speed is the problem and I know it is because target ammo cured the issue...then how would increasing bolt speed even more allow this gun to function with hi-speed ammo???? A stronger or new spring would allow the bolt to return even faster, how fast it flies back is not the issue because the gun functions perfectly up that point, it's the return of the bolt to battery that is when the jam occurs.
Again, when I swapped out the action spring assembly with a newer, known good functioning assembly it did nothing to correct the problem with this pistol. When I placed this pistols assembly in another gun it {that gun} worked OK.

A stronger recoil spring would decelerate the bolt going back and prevent in from rebounding to strongly, yes it would have more energy coming forward because of the stronger spring, it would not necessarily be going any faster. You would have to find the sweet spot of each spring/bolt combo, just like guys do with their 1911 race guns.
 
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