Hand made 1950 spring loaded firing pin

[theSKSguy45]

The 1950 sks I recently acquired had a broken firing pin. After looking at it for a bit I decided to attempt to make my own replacement. Considering I don’t have access to a lathe and this was done with a grinder, drill, and dremel I think it turned out well. I used a maxim punch like the one shown in the photos as a base. Any thoughts about if I should be heat treating it? Where should and shouldn’t be hardened? And any feedback in general is welcome.

Worst case scenario my replacement breaks and I need to source a new one.

IMPORTANT EDIT: do not manufacture your pin in the way shown. If you look at the comparison between the original bolt and mine you will see the back of the original pin has two steps machined at about a 45 degree angle where as mine does not. These are important. If you do not include them the bolt carrier will prematurely push on the firing pin without any input from the hammer, potentially causing a premature detonation or even an out of battery detonation. I’ve since fixed it on my pin. I caught this before attempting a live fire thankfully.

Mine updated (left) Murray’s (right)


Starting to remove material

The part is starting to take shape

The end result (left), the broken pin that came with the rifle (middle), an original pin from another rifle (right)

Rear of all 3 pins

My pin installed (left) original pin installed (right)

Installed pins from the rear

Installed pins from the side

[echo1]

Great job, does it work? PAX

[theSKSguy45]

We will find out in a couple hours

[Witchywoman]

Its amazing that you did that with a drill and no lathe or CNC. I kick myself because when my uncle passed away, our family automatic transmission shop had 2 WW2 era huge lathes in the back room and a drill press where my uncle often machined parts or cleaned them up. They both worked perfectly. My mother just ended up selling them as a bulk buy with everything else on the premises so someone got 2 free lathes in the process. A huge waste.

Curious to if this worked successfully. You got your own Khyber pass operation going on there. 

[echo1]

The Khyber Pass Fab team is close to my heart. If I could melt steel with fire I'd be dangerous  PAX

[theSKSguy45]

Did a post-range trip cleaning and the rifle is perfectly functional now. The pin worked exactly as intended however the bore needs some work.

5 shots at 50 yards with the sights set to 200M (notice the potential keyhole on the top left and definit keyhole on the bottom right). 2 missed entirely.


Now 5 shots at 5 yards, one potential keyhole.


Now splitting the difference with 5 shots at 25 yards you see multiple keyholes.

[Greasemonkey]

I've never seen a SKS keyhole. I wonder if someone used a drill to counterbore it, a counter bored SKS is odd to begin with.  If the crown down in the counterbore is uneven, rough or jagged cut that may come into play and cause the keyhole issue.

One thing you could do is slug the bore and measure to see how bad it is.  Or even better, if you have a bore scope or a buddy with one to see what exactly is lurking down in there. I recently got one and it's blown my mind how what looks like a nice shiny barrel can actually be horrid sewer pipe down deep inside.

[echo1]

On the barrel chop jobs I've done, I borrowed tools from my buddy, muzzle facing tool and a 2* crowning tool. I've gone about halfway out from the barrels OD at what I hoped was square. So far so good. But on does shoot around corners  PAX

[theSKSguy45]

The bore for the last two inches (not including the counter bored section) is almost smooth where as about where the gas port is it starts to look a lot more like what I’d expect a Soviet rifle to look like. I don’t have access to a bore scope unfortunately. I'll grab some pictures real quick.

[theSKSguy45]

Here are the best photos I could get of the counter bore. Noticeably off centre. When I was shooting I was noticing what I thought to be sparks flying out of the muzzle.

[echo1]

Sounds like it's toast. What I've also done with the last 2 barrel jobs I cut to 18.5" then recrowned. At that length there's enough muzzle OD undercut left to hack off the front sight globe and slip it over the barrel tip.
Doesn't look Bubba at all.  PAX


Mojo rear sight, 5 round mag,


Butler Creek furniture all and all a good save for a one way trip

[Greasemonkey]

Yeah it's off center.. I don't think that's causing the issue... But, the last two inches you say is.. sketchy and smooth, sounds like someone got aggressive and ramrodded it with a steel cleaning rod without a muzzle protector and then tried to counterbore their mistake away.  It doesn't look like they went but maybe a 1/2 to maybe 3/4 inch in with the counterbore, which probably wasn't enough, I've seen Mosins counterbored between 2 or 3 inches.

Just for $hits and giggles  I mean call it a learning experience, or an experiment..... You made a firing pin, that part is kinda cool    so... (I'll probably get flamed for this, oh well, it's kinda my thing) maybe try to counter bore it deeper, like thru the worn 2 inches and get it square..  honestly, you've said you have a spare barrel...   What's it gonna hurt to try?   It probably wouldn't shoot any worse and may actually get better to an extent.

It may.... Or it may not.... You just have to see how it responds.... but it could have an effect on the gas system, but I'm sure that even that could be resolved, Pax or GG might need to correct me, but the Paras I believe have a slightly larger gas port to compensate for the shorter barrel, and the loss of pressure due to that fact. Basically you would kinda be creating a Para with a normal length barrel.  Like I said.. it's messed up anyway, it's kinda the perfect learning and experimenting tool at the moment.... Cause I'd probably do it if I had it, just to see.. 

[running-man]

GM, you're going to work the poor man to death!  It may be easier to just chop 4 inches off it and call it a paratrooper (or Russian tanker) if you prefer.   

But in seriousness, if you are going to go through the process of fixing the key-holeing, chopping the problematic end portion of the barrel off is what I'd consider first to be honest.  As GM says, you can always swap barrels if you decide you *really* don't like having a 16" SKS or if it still shoots poorly.

You also might try different ammo.  I remember Dannyboy53 had a Russian SKS that would keyhole with Golden tiger ammo, but shot perfectly fine with Tula and Brown Bear. 

[Greasemonkey]

   call it practice.. what fun is instant gratification.

I was gonna mention changing ammo, but figured if it's been rode that hard and no rifling in that area, it probably wouldn't make much difference.

I don't know if since he is in Canada how much he can chop... I think they probably have their own barrel length law.   I have enough problems keeping up with some of the law jibberish here.

[theSKSguy45]

Honestly even if chopping was an option (18.5 is the legal cutoff for nr rifles in Canada) I’ve already done that and would like to try something new. I’ve got no issue trying to counter bore it but given the quality of barrel I’m looking at, I’m more interested in replacing it entirely. I don’t mind using a Chinese barrel since it won’t be original no matter what I do short of leaving it as is. Plus having a chrome lined bore is always nice. I think when the barrel comes off I’ll chop the portion that was messed with and maybe counter bore the remainder as practice. Maybe even use it in a build I’m thinking of doing with all the other bubba victim parts I’ve acquired (if I go through with it it will be one of the most… interesting sks rifles you’ve ever seen).

As I’m writing this I am prepping the barrelled action for de-population and hopefully the swap happens sometime this week

[running-man]

Good luck.  Make sure you have a relatively stable cheater bar and a solid wrench as well.  When LC pulled the barrels off his at Murray's to check if our hypothesis on the clocking numbers was right, they required a good amount of umph to get off.  Many hundred foot-lbs if I remember correctly.  Going on is a bit easier because you have stop when you've oriented the flats horizontally (though I can see being short by 10° [i.e. mating a #5 barrel to a #6 receiver] requiring a ridiculous amount of torque to get things oriented correctly).

Take some photos of your process if you don't mind, lots of guys would love to see how it plays out! 

[echo1]

When you get that other bad barrel off, inspect closely and if doable and affordable, remove the front sight base and turn down the muzzle to fit the FSB and bayo lugs. Then you'd have a legit Para length Russian unit for a known receiver if ever desired. PAX