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View Full Version : Slam fires, firing pins, and other things



YVRguy
02-20-2017, 06:06 PM
I finally made it out to the range this past weekend with my brand new Beretta 92FS and (new to me) SKS. Fun stuff.

Regarding the SKS, I have read much about the need to do a thorough initial cleaning to ensure all the of the cosmoline has been removed. My buddy and I did this and even removed the firing pin for cleaning. That said, people still talk about the risk of slam-fires with the SKS - even with a clean gun. I'm also reading about the spring-loaded firing pin mod. In the real world is this really necessary? Seems like an easy mod if it makes a difference but I don't want to chase my tail on this. For what it's worth, the gun performed flawlessly the first time out.

Also wanted to ask about ammo. I bought a can of milsurp ammo to shoot but my range master said club policy is NO FMJ AMMO. On an outdoor range. Dutifully I went out and bought some soft tip stuff that I was fortunate to find but I'm disappointed to learn about this restriction. Is this a common policy?

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greywolf67nt
02-20-2017, 07:14 PM
Did the range master mean no FMJ or mistakenly referring to the milsurp as that even though they meant steel?
I have seen a couple threads kicking around lately about ranges not allowing FMJ though as well.
As far as slam fire in the SKS I have put thousands of rounds through mine and NEVER had one and I am TERRIBLE at cleaning mine. Fortunately humidity where I live is practically zero so don't worry a whole lot about corrosion. The firing pin spring IIRC is on certain models not an after market modification. Those that know more can correct me if I'm wrong.

YVRguy
02-20-2017, 09:16 PM
Here is an example of an aftermarket firing pin with a spring

http://www.brownells.com/rifle-parts/bolt-parts/firing-pin-parts/firing-pins/sks-firing-pin-sku563000001-24637-51298.aspx?sku=563000001&avad=avant&aid=160163&cm_mmc=affiliate-_-Itwine-_-Avantlink-_-Custom+Link&utm_medium=affiliate&utm_source=Avantlink&utm_content=NA&utm_campaign=Itwine



Did the range master mean no FMJ or mistakenly referring to the milsurp as that even though they meant steel?
I have seen a couple threads kicking around lately about ranges not allowing FMJ though as well.
As far as slam fire in the SKS I have put thousands of rounds through mine and NEVER had one and I am TERRIBLE at cleaning mine. Fortunately humidity where I live is practically zero so don't worry a whole lot about corrosion. The firing pin spring IIRC is on certain models not an after market modification. Those that know more can correct me if I'm wrong.

lone-wolf
02-20-2017, 09:22 PM
Re: Firing pin spring - MIGHT be useful when using commercial hunting loads with softer primers than the surplus.


firing pin spring IIRC is on certain models
The 49? Russian SKS originally had spring loaded firing pins. Later models dropped it. Don't think any other countries had any with them.

Deuce-deuce
02-20-2017, 09:34 PM
Hmmmm.... I wonder if anybody has had an issue with hunting ammo. It'd be pretty surprising to get an unintentional double tap with a deer in the sights.

kennymo
02-21-2017, 01:23 AM
I've never known anyone to get a double tap with a well maintained SKS, commercial ammo or not. One of mine let off two in a row on it's first range trip. A little more spray degreaser in the firing pin channel seems to have solved it permanently.

MarkR
02-21-2017, 04:35 AM
Here is an example of an aftermarket firing pin with a spring

http://www.brownells.com/rifle-parts/bolt-parts/firing-pin-parts/firing-pins/sks-firing-pin-sku563000001-24637-51298.aspx?sku=563000001&avad=avant&aid=160163&cm_mmc=affiliate-_-Itwine-_-Avantlink-_-Custom+Link&utm_medium=affiliate&utm_source=Avantlink&utm_content=NA&utm_campaign=Itwine

While this seems like a good idea, and I considered doing this for my rifle, the Murray's pin (because of the reduced diameter to accommodate the spring) has been known to break occasionally. So, I figure that 100s of thousands of these have been in service without.

Good enough for me.

Zeegler
02-21-2017, 12:11 PM
Re: Firing pin spring - MIGHT be useful when using commercial hunting loads with softer primers than the surplus.


The 49? Russian SKS originally had spring loaded firing pins. Later models dropped it. Don't think any other countries had any with them.
49s and early 50s as far as I know. Mine's a 1950 and has the original sprung pin.

Sent from my Nexus 6P using Tapatalk

Bubba Yugga
02-21-2017, 06:01 PM
Scuttlebutt I heard is that the floating pin was introduced near the end of 1950, and the barrel started getting chromed in the spring of 1951.

Deuce-deuce
02-21-2017, 06:29 PM
I've never known anyone to get a double tap with a well maintained SKS, commercial ammo or not. One of mine let off two in a row on it's first range trip. A little more spray degreaser in the firing pin channel seems to have solved it permanently.

I too haven't experienced the dreaded sks slamfire... but the internet says it happens. Must be true.

TheGreatBeard
02-21-2017, 06:38 PM
I have SKS's with and without a spring loaded firing pin and I've never had a slamfire. I just make sure they're cleaned because of what others have said but it has yet to happen to me.

MarkR
02-22-2017, 03:39 AM
Here is an example of an aftermarket firing pin with a spring

http://www.brownells.com/rifle-parts/bolt-parts/firing-pin-parts/firing-pins/sks-firing-pin-sku563000001-24637-51298.aspx?sku=563000001&avad=avant&aid=160163&cm_mmc=affiliate-_-Itwine-_-Avantlink-_-Custom+Link&utm_medium=affiliate&utm_source=Avantlink&utm_content=NA&utm_campaign=Itwine

I have heard that since there is less material in the pin to accommodate the spring, these are sometimes prone to breakage.

Steveo9mm
02-22-2017, 09:21 AM
i boiled the crap out of mine to get all the cosmoline off and then wd40'd the snot out of it.

YVRguy
02-22-2017, 07:49 PM
When you clean do you go to the extent of removing/cleaning the firing pin?


I have SKS's with and without a spring loaded firing pin and I've never had a slamfire. I just make sure they're cleaned because of what others have said but it has yet to happen to me.

graz
02-23-2017, 09:46 AM
Also wanted to ask about ammo. I bought a can of milsurp ammo to shoot but my range master said club policy is NO FMJ AMMO. On an outdoor range. Dutifully I went out and bought some soft tip stuff that I was fortunate to find but I'm disappointed to learn about this restriction. Is this a common policy?

What range is this...?? Secondly, is this written down or just another RO's version of the rules he would like to have?

Plinker 777
02-23-2017, 04:55 PM
OP, there's nothing wrong with the floating pin. Your gun isn't broke, don't try to fix it. Now having said that, do I make sure the muzzle is on target and down range EVERY TIME I let the bolt slam home? Yep...always, every time.

Why?...How these two little a$$holes haven't managed to shoot one another is dead is beyond me...I do not abide by someone sweeping the back of my head like this...I will (and have) completely lost my sh1t at the range when someone points a muzzle my way.

Right click the image into a new screen.
https://youtu.be/9jtxMPAXWV8?t=2

Anyhow, maintenance is key, but so is muzzle and trigger control. For me, if I haven't done a deep clean in a while and an SKS follows me to the range, I'll strip the top cover and give the bolt a shake, if it rattles I know I'm GTG.
Still, know your gun. What it is capable of and always respect it...Seamore and Dolittle above are terminally f**ked if they don't learn as they grow up. Been a while since I've seen something so stupid.

YVRguy
02-24-2017, 08:53 AM
That's the confirmation I was looking for - "if the firing pin moves freely you're GTG". No idea what you're talking about regarding the two people, your attachment isn't showing. But I agree completely with your thoughts on muzzle control.


OP, there's nothing wrong with the floating pin. Your gun isn't broke, don't try to fix it. Now having said that, do I make sure the muzzle is on target and down range EVERY TIME I let the bolt slam home? Yep...always, every time.

Why?...How these two little a$$holes haven't managed to shoot one another is dead is beyond me...I do not abide by someone sweeping the back of my head like this...I will (and have) completely lost my sh1t at the range when someone points a muzzle my way.

Right click the image into a new screen.
https://youtu.be/9jtxMPAXWV8?t=2

Anyhow, maintenance is key, but so is muzzle and trigger control. For me, if I haven't done a deep clean in a while and an SKS follows me to the range, I'll strip the top cover and give the bolt a shake, if it rattles I know I'm GTG.
Still, know your gun. What it is capable of and always respect it...Seamore and Dolittle above are terminally f**ked if they don't learn as they grow up. Been a while since I've seen something so stupid.

Plinker 777
02-24-2017, 06:11 PM
^^^Right mouse or touchpad click when you hover over the green square. then click "open image in new tab". The video will show two kids sweeping muzzles, and at one point in time the sks goes off, actually narrowly missing the one kid as he was swept by the other.:eek1:

In any event; yea, pull the bolt and give it a shake in your hand. If it (the firing pin) rattles, you're GTG. I'll give it a shot of RemOil, pop it back in, dust cover on, and blast away.

Doug The Slug
06-20-2017, 06:12 PM
At EOSC near Cheney Ontario, most of the guys use FMJ because it's cheap especially when your firing 40+ rounds in a MILSRP match. There is a big sand berm for a backstop though, don't know what you have at your club.

Swingerguy
06-20-2017, 06:41 PM
Also wanted to ask about ammo. I bought a can of milsurp ammo to shoot but my range master said club policy is NO FMJ AMMO. On an outdoor range. Dutifully I went out and bought some soft tip stuff that I was fortunate to find but I'm disappointed to learn about this restriction. Is this a common policy?

I had an RO mistakenly tell me that no FMJ ammo was allowed at the indoor range when what he meant was no steel core ammo was allowed.

Wendell
06-20-2017, 07:03 PM
Some outdoor ranges have steel targets. Some FMJ 7.62x39mm is steel core, which can damage some steel targets. It doesn't surprise me that a range might have a range officer who doesn't approve of that.

WSA
06-20-2017, 10:06 PM
Wendell, this isn't directed at you, since I know you are just providing information, I'm just clarifying something...

It may be range rules but steel core 7.62x39 ammo doesn't damage proper AR500 steel targets one bit. Oh sure, after thousands of rounds they might start to chip and crack, but that's the nature of steel targets. I speak from lots of experience with this :)

On the topic of slam fires with the SKS, I think there are 2 ways, both that have happened to me. Dirty firing pin (No rattle) and a worn sear. Only experienced the worn sear with one of my SKS, and that was after about 10 000 rounds or more. A new trigger group for about $45 fixed that issue.

Booletsnotreactwell
06-21-2017, 07:40 AM
Some outdoor ranges have steel targets. Some FMJ 7.62x39mm is steel core, which can damage some steel targets. It doesn't surprise me that a range might have a range officer who doesn't approve of that.


It may be range rules but steel core 7.62x39 ammo doesn't damage proper AR500 steel targets one bit. Oh sure, after thousands of rounds they might start to chip and crack, but that's the nature of steel targets. I speak from lots of experience with this :).

This.

I have real properly made AR500 targets, most of the surplus ammo, 7.62x39, 7.62x54R, etc is all mild steel core ammo. New production stuff like Barnaul, Tula, Wolf, etc is all mild steel jacket only which doesn't do anything. I've blasted the living shit, in the 10,000+ range of these various forms of ammo on a steel IPSC silhouette target, it's perfectly fine.

Ranges ban it because there's a misconception that it'll destroy their targets, yet comically they'll allow and have no problem with somebody shooting a 22-250 copper solid at 4000ft/s which will leave large dents at close range to AR500 targets. AR450 or bellow, it can blow hole clean right through it.


Banning steel core, I can live with that and see why, it might damage something. Banning steel jackets (Barnaul, Tula, etc) is dumb but I can understand it because it's hard to tell the difference between steel jacket and steel core, it's all equally magnetic.


Banning FMJ, as in copper jacket around a lead slug (what FMJ actually means), as in the type of ammo that's been used since the early 1900's and the advent of bolt actions. Straight up retarded.

Justice
06-21-2017, 10:22 AM
Slam fires are primarily caused by improperly reloaded ammo(usually high primers) and have nothing to do with the rifle at all. Unless the fp is broken or the bolt is really dirty, there's no reason to think an SKS' fp will get stuck out anyway. The rifle was designed to be issued to illiterate conscripts who were taught to use and maintain the thing as fast as possible.
A no FMJ rule is usually caused by some bonehead shooting rapid fire with no control. Can cause damage to range facilities. Mind you, any jacketed bullet can do that. Also it's usually no AP or milsurp ammo. Commercial FMJ's aren't the same thing. And there's a misconception that FMJ's cause sparks and thusly range fires.

6MT
06-21-2017, 10:57 AM
He does probably mean no steel core ammo. They're worried that their targets won't survive long with the harder ammo.

WSA
06-21-2017, 06:27 PM
Slam fires are primarily caused by improperly reloaded ammo(usually high primers) and have nothing to do with the rifle at all..

Slam fires from an SKS using surplus or commercial ammo has EVERYTHING to do with the rifle. And it's not terribly uncommon.

Wendell
06-26-2017, 12:30 PM
...this isn't directed at you, since I know you are just providing information, I'm just clarifying something...steel core 7.62x39 ammo doesn't damage proper AR500 steel targets one bit. Oh sure, after thousands of rounds they might start to chip and crack, but that's the nature of steel targets. I speak from lots of experience with this...

I too, speak from experience, having made the mistake of having left a brand-new AR500 pistol-rated swinger in the shack at the range. About four days later, I returned to find about 150-200 fired steel-case 7.62x39 cartridges (left on the deck, naturally, for me to pick up) and my now-destroyed AR500 pistol-rated swinger, left outside.

There's something about the behaviour of the type of people who are attracted to cheap SKSs and cheap steel-case ammunition that makes me feel like a real FUDD.

WSA
06-26-2017, 01:49 PM
That sucks.

Yes, all sorts of stupidity done at ranges to targets that belong to someone else. Every rimfire target I've seen left at the range seems to get shot by a 300 magnum, people will staple paper targets to target stand uprights and pistol targets get shot at close range by rifles, like yours.

6MT
06-26-2017, 08:47 PM
...

YVRguy
06-27-2017, 01:17 PM
Just to confirm on this, the problem arose when a couple of yahoos shot the hell out of a brand new steel target. Most likely with milsurp ammo. I'm new to that club so I think the rangemaster is trying to err on the side of caution with me seeing as I have the same kind of ammo. I tried telling him I'm just going to shoot paper but he was having none of it.

Booletsnotreactwell
06-29-2017, 08:19 AM
AR500 pistol-rated swinger

I've never heard of "pistol rated AR500", it would be sort of like saying "pistol rated NIJ level 4 armor plates". The number refers to the rating on the Brinell scale so it's either 500 or it's not. There's a little more that goes into what makes a steel target able to stand up to rifle hits but really it starts with having a high quality steel that's finished by a target manufacture that knows what they're doing. Maybe manufacturers sell their scraps and shit products under the banner of "pistol rated AR500", which is somewhat deceptive, either way whoever sold you "pistol rated AR500" sold you bullshit.

True quality AR500 from a good manufacturer should take steel core/bi-metal jacket/core and anything but dedicated armor piercing rounds all day as has been my experience and the experience of many others. While were at this, a good manufacturer of steel targets cuts the targets by water jet, if it's cut by a torch the edges become sub par and susceptible to things normal AR500 doesn't get hurt by.



There seems to be a lot of misguided blame on SKS's and surplus low velocity bi-metal rounds. So much so that some fud ranges ban them yet some fud cartridges like copper solid 22-250 rounds will punch right through AR500 plate body armor.

Wendell
06-30-2017, 05:47 PM
...Maybe manufacturers sell their scraps and shit products under the banner of "pistol rated AR500", which is somewhat deceptive, either way whoever sold you "pistol rated AR500" sold you bullshit...

Maybe some pistols have less energy than some rifles. Maybe a 'rifle-rated' plate wouldn't swing in reaction to a hit from some pistols. Maybe some target shooters like their steel to swing in reaction to a hit. Maybe not all AR500 plate comes in the same thickness. Maybe some manufacturers actually label their product both 'AR500' and 'centerfire pistol only'.

Late entry:

You are correct, the label said it was safe to engage them with rifle fire from 100 yards or greater. They were rated for centerfire pistol (from any distance).

The yahoos who did this left their (steel 7.62 x 39mm) cases behind at the 10m range.

Wendell
06-30-2017, 06:05 PM
Targets by AR500 ArmorŪ are rated for use with most common pistol calibers at a distance of no less than 7 meters and most common rifle calibers at a distance of 50 meters. We strongly discourage the use of steel core ammunition. (http://www.ar500armor.com/targets.html)

WSA
06-30-2017, 06:46 PM
Pistol rated AR500 targets are basically thinner. 1/4" rather than 3/8" or 1/2". A properly made 1/4" pistol swinging target will soak up thousands and thousands of pistol hits at 10m with very little damage. A .223 at 100m will dent a 1/4" target and have a bit of a protrusion on the off side. At close range they can get shot to hell with a rifle.

Even a 3/8" target will get shot to heck by fast moving rifles at 20 yards. At 50 yards a 3/8" swinging target will soak up plenty of 7.62x39 or .223, but a 300 Magnum will start to beat them up a fair bit. Stationary (rather than swinging) targets get beat up more. A 1/2" AR500 target will last a very long time at 100m no matter what you throw at it, short of a 50BMG or 338 Lapua.

A .223 is more damaging than bimetal 7.62x39, becuase the .223 is 1000fps faster.

No matter what you shoot steel with, make sure you wear eye protection. The shrapnel goes everywhere, and when it hits you in the face it doesn't bother you too much but getting it in the eye is a while different matter.

RedZedX3
09-15-2018, 07:41 PM
I know old post is old, but I recently purchased a Chinese Type 56 and experienced my first slam fire.

The slam fire happened when releasing the bolt. I had loaded a single round into the chamber with no magazine in place. The round went off, ejected as normal, and the primer had a pin mark on it even though I hadn't touched the trigger (which was actually on safe). I slowly slid the bolt assembly forward and watched to make sure the firing pin did not push forward in any way. Everything looked normal.

I removed the trigger assembly, loaded a round, and released the bolt. Nothing happened. At this point I figured it had to be something in the trigger group.

When the rifle first arrived, I tore it down to "nuts and bolts" to clean everything after finding all kinds of lovely grit under the sear on my Tula. The entire trigger assembly and the firing pin/bolt were spotless before reassembly, so I am 100% sure it didn't happen as a result of cosmoline. At the time, I was shooting Hornady SSTs, which had no issue in my Russian rifle.

Just a little bit ago, I pulled the trigger group apart to look at the engagement surfaces on the hammer and sear. It appears as though the surface on top of the sear is worn resulting in negative engagement. The Yooper website is a lifesaver when it comes to troubleshooting. Not sure if I can clean up the surface or if I have to buy a new sear, but this goes to show it's not always dirt or bad ammo.

hical.ca
09-16-2018, 09:05 AM
Well, we stock all the USA made Murray SKS parts from the spring loaded firing pin to sears & springs. Some pins had breakage problems due to poor hardening a few years ago, but they have no problems now & are guaranteed....Have a look, HERE. (http://hical.ca/search.php?search_query=murray&x=0&y=0)

RedZedX3
09-16-2018, 07:40 PM
The pic isn't the clearest, but you can see there is a second "step" that angles back towards the hammer. I removed the hammer spring and reassembled the trigger group to check the contact between the hammer and the sear. It didn't take much to make the hammer drop. I haven't tried testing it with the trigger group installed in the rifle, but I can guess what the result will be.

Even if I restore the angle, I'm not sure the hammer will stay cocked since filing would remove material creating more of a gap between the hammer and sear. Plus it may impact the hardened surface on the sear (if any remains). I did find pics on Survivor's SKS Boards that look similar to my predicament where the positive engagement was reestablished.

I should probably mention that my intent is to make the rifle safe and reliable. I've seen the videos on trigger jobs; I only want to restore original operation.

9259

hical.ca
09-18-2018, 10:50 AM
Check the Murray sears, they will correct your problem.

RedZedX3
09-26-2018, 06:52 PM
Check the Murray sears, they will correct your problem.

This is likely the way I'll have to go. I can get a full trigger group for $45, but it is still surplus so it may not be in better condition. Have to wait until the OT fairies show up on my next paycheck.