Murray's Firing Pin Kit and Gas Valve for the Yugo SKS

Below are a couple of quick movie clips I made tonight while installing Ben Murray's firing pin kit. The kit comes with a new stainless steel firing pin and 2 springs. Yugo firing pins are free floating and if they stick for some reason, it will result in a 'slam-fire', which means that your semi-auto will fire full-auto until your magazine is empty. Ben's kit adds a return spring to the mix so this doesn't happen.

Ben sent me a kit to try out so I installed it tonight. To swap out the pins, all you need to do is hammer out the firing pin retainer, which is a pin that keeps the firing pin locked in the bolt. Once that pin is removed, the old pin slides right out and you can replace it with Ben's kit. Simply slide one of the two springs that comes with the kit over the new pin, slide it into the hole and reinsert the retainer pin. I suggest checking the bolt and pin during each cleaning to be sure that the pin is functioning properly. Should the spring ever break, immediately replace it with the extra that comes in the kit.

Removing the firing pin retainer


The bolt with new spring-loaded kit installed

Here's the original letter I received from Ben:

...I’d like to send you a Firing Pin Kit and a Gas Valve. We've heard reports that when (one of our competitor's) valves are installed, the gas hole in the valve does not correctly line up with the hole in the gas block/barrel. Maybe there are only a few that are mis-aligned but that is the type of quality control that makes us feel like ours are slightly better. But it’s not just that. Ours are also different in the fact that ours are machined slightly oversize, especially to help get the older, more used 59/66’s running again. Plus, customers have their choice of an “original” style Valve, that uses the original spring loaded button/selector, or our “New Style” that has a socket head cap screw , that’s used in place of the spring loaded button. And we even include an Allen wrench. Allows semi-permanent positioning of the valve so it can’t be accidentally knocked out of position. One customer in particular uses this version to “lock” it into single-shot mode while his 17 yr old son is deer hunting in a deer stand nearby, but not directly chaperoned. Ours are made from SS as this seems to make the inevitable cleaning of the carbon build-up on the valve much easier. While you may not have an “older, more used” Yugo to test it on, you could install it in the gas block, note the tighter fit you will feel, and at least start to install the gas tube on it, and again feel the tightness difference. Ours are advertised on our site for $21.00. But this includes CC fee and shipping. (First Class) So I believe they will only be slightly higher than theirs once shipping and/or CC fee are added...
Hope you and yours have a very Merry Christmas.
Thanks ~Ben Murray, ben@murraysguns.com
http://www.murraysguns.com/sksown.htm

I discovered a broken spring in one of my bolts and asked Ben why this occurred. Here's some interesting info he just sent me:

READ: Popped Primer(s) www.murraysguns.com/poppedprimers.htm
This is one of the attributes of our firing pin kit. When a hole gets blown through a primer, hot gas blows back through the firing pin hole with significant force. Enough in some cases to blow an “original free-floating” FP out the back of the bolt. The bump on the FP that is supposed to stop rearward movement against Retaining Pin becomes sheared off at worst and often times bent, and begins sticking both rearward and forward. But, with our FP Kit the spring is usually all that is damaged. The “Murrays” FP, even without a spring, will still function safely. But we supply replacement springs, no charge. This only happens with the imported (mostly Russian) “Berdan” primed ammo. With American, or any “Boxer” primed ammo, this will never occur. It only takes one “popped primer” incident to fry our spring.

Seems like a great reason to start reloading my own 7.62x39 ammo.