MN perpetually poor pin pertrusion problems

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Ratfood

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Hi folks, my type 53 is giving me some problems.
My firing pin is sticking out .110 "and I know it's max should be .095" A nice man named Frank on surplusrifle forum told me how to adjust my firing pin so I gave that a try. The problem is that I screw my pin in just as far as it will go (till the threads run out) and then back it out about 1/8 turn to match the timing lines. Now at this point the rear of the pin is actually sticking out the back of the cocking knob a thread or two. Then I measure the protrusion and it is still .110" (holy moly!) I think the pin is just too long for the bolt!

I ran across some instructions on how to shorten a pin on a web page somewhere with a file and some sandpaper (it was for a different kind of rifle) and I was just wondering if there was any reason why I shouldn't do this?

By the way, I shot about 15 rounds of Check silver-tip thru the rifle and no pierced primers but Im gonna step up to some Bulgarian heavy ammo with a little more macho and don't wanna go blind just in case. Thanks for any help!
 
Could be a headspace problem. The firing pin is sticking out far enough, but there is too much space between the cartridge and the bolt or the cartridge is moving forward when the firing pin hits the hard military primer.
 
Darryl said he checked headspace before he shipped them so it should be OK. However, I can buy a field guage, and I have 3 other type 53's I can swap parts with. You think I should just swap out the whole bolt with another 53 that I'm not going to shoot for a while (after field guaging it)? I have four 53's with unmatching numbers so I can swap out whatever.
so, If buying a field head guage and swapping out parts till I get two working guns seems the easiest then I'll just do that~
 
Ratfood, the headspace is dead on, There is something going on here though and I'm suspecting it has to do with your measuring, there simply is no way possible to have the same measurment with the pin turned in as with it turned out that simply isn't possible, do ya have a mosin Protrusion tool?

Now were ya getting punctured primers with the pin set in its original position with the rear flush?

Can ya post some pics of how your measuring it?

PLZ do not trim anything at this time as its simply not possible to keep getting that measurment after turning it back, I'm suspecting we got something else goin on here.. Do me a favor if ya got a caliper then measure from the front of the collar on the FP to the tip of the pin will ya?

DMK, he is mearuring the fireing pin protrusion....... has nothing to do with headspace as your measuring how far the pin is sticking out of the bolt face..... and he's saying that if he shortens the fireing pin ie; turns it in until it is sticking out of the back of the cocking piece he is getting the exact identical measurment he was getting when the pin was turned in and flush with the cocking piece....... the bolt isn't even in the rifle so no possibility of headspace having anything to do with it he simply cannot get the same measurment with two different adjustments, this adjustment only pertains to preventing primers being punctured due to too long of a fireing pin......

I just tried to get ya some pics but..... I suck at indoor pictures so will have to wait till tommorow, IF ya actually had .110 protrusion there would very deffinetly be pierced primers which ya aren't getting, BTW The measurment on several actual MN Protrusion gauges all come up with .076" consistantly, I would start by setting it right back to flush for starters.

A side note bout Mosin Nagant headspace adjustment, they are adjustable just like an Enfield ya don't have to swap bolts ya just swap bolt heads.... they are just easier than an Enfield as ya don't even have to unscrew them just turn one off and the next on ;)
 
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OK thanks Dstorm! , I will take a picture of how I am measuring the pin protrusion and post it up here after I eat tacos for dinner. I know I have to be doing something wrong because when I unscrew the pin a few turns and put the bolt back together there is a space between the connector bar and the bolt body. I can't push it down any further. I will put up pics shortly.

I know when all is said and done we are going to reach the conclusion that I am a complete idiot. But im told getting there is half the fun. Thanks again~
 
OK here are the pics with the pin screwed all the way in:
 

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Here are the pics when I unscrew the pin a few turns: Instead of the pin sticking out farther, this "bad space"/gap opens up instead.
 

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Here are pictures of me measuring the protrusion~

It is at .110" every time, screwed in or screwed out (because of the bad gap I presume)
 

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It looks to me, you're unscrewing it the wrong way. You should be turning it so that it sticks out the back of the cocking knob to decrease protrusion.

You should also get one of the issue combination tools to measure with.
 
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When I measure the protrusion on the other t53's this way they all measure within spec. It's just this one thats giving me this problem. If you need any other pictures please let me know~
 
OK when I tighten it all the way into the bolt (the other way) It goes all the way in till it won't turn any more. Then I measure it and it's still over the .095" limit. Thats why I thought I should have to cut the pin down a bit.
 
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O.K I'm tryin to figure this one out, unscrew the fireing pin and remove it completally, measure total leangth, then the leangth of each section of the fireing pin then the thickness of the connector collar.

BTW thats an Ishvesk connector, what arsenal marks are on the rest of the bolt parts? It was very common to have Russian parts in the T-53s that one has the arrow in triangle marking in onea your picks.

It shouldn't have any bearing on your issue though as ya simply cannot get the exact same protrusion measurement when the pin is all the way in and all the way out, it just can't happen so something is going on here I just gotta figure it out, Don took off to the vegas show and I'm gonna be buildin racks down in my gun vaults over the weekend but I got a bunch of T-53 bolts in a box I'm gonna try and duplicate this problem, in the meanwhile don't be cutting anything if we can't figure it out I'll get ya to send me that bolt and we'll send ya a new one (We can get the headspace by useing your bolt head but I want to make sure if we swap out the bolts its not something strange with your bolt head.....

IN FACT!! Try swapping bolt heads with one of your other bolts then measuring, make sure not to lose track of this one as its headspaced to that rifle but just try swapping components and see what happens, try the bolt heads first then the connector then cocking piece the only part ya must keep track of is the bolt heads themselves everything else has no relevance to the rifles headspace and if it is a bolt head issue I can measure yours and replace it without effecting your headspace (we got a few hundred) so no worry we'll get this sorted out, oh and don't forget to compare the fireing pins while your at it.

DStorm
 
I'VE GOT IT!! Swap your fireing pin spring with onea your other bolts! I'll bet the spring is short or collapsed.

Let me know, I'm gonna git to bed before my other half gets any madder ;)
 
heh, thanks Dstorm, go get some rest. I will start marking and measuring parts tomorrow, I gotta get to bed too or the old lady won't let me go shooting this weekend... I'll get you all the info you asked and see if we can get to the bottom of this.
See ya....
 
I think we finally got it figured out. You were right Dstorm, the spring on the problem bolt was shorter than the rest. So I spent all morning measuring parts between 4 different bolts, and swapping out parts, and measuring again, and so on and so on. Anyhow, I found were that on the problem bolt there were a few small problems:
1) The "ring" that sticks out on the firing pin ended up being about .01" thicker than the other pins' rings.
2) The spring was almost .1" shorter than the rest.
3) The cocking knob on the problem bolt was off by ~.015" lengthwise (I can't remember which way) than the other cocking knobs.

Now when I changed the problem cocking knob with ones on other bolts everything came into spec. Now correct me if I am wrong, but is it possible that all these slight measurement deviations could have caused a cumulative effect which caused the original problem? (please say yes)

Now assuming this is true, this leaves me with one or two more questions. Since I swapped out the cocking knob with another bolt, and both the firing pins are now .080" can I just leave it at that and go shoot? I guess the real question is, does changing out a cocking knob affect headspace clearance? If so, a field guage will tell me all I need to know right?

Thanks again~
 
yep its called tolerance stacking, and yes ya can leave em as ya now got em.... sorry can't get into details tore up wrist and it hard to type but your good to go!!! congrats only thing period that effects headspace is the bolt heads nothing else matters as far as the bolts
 
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