Two Rounds on a Single Trigger Pull AK-47

[milrifle]

My wife bought her a CAI imported Serbian made AK-47 copy at a gun show a while back. Today, we were trying out some reloads using the Lee 309-155 over 18gr of RL-7 and a CCI LR primer. When she pulled the trigger, much to her surprise, she sent two rounds downrange. Upon inspecting the case, I found the primer was just barely dented on that second round. My first thought was that the disconnector had failed and the hammer had ridden up the back of the bolt. I used to have a friend with an AR-15 that would go full auto without the automatic sear if it were put into what would have been "Auto" position on an M-16. I thought maybe the same thing had happened with the AK. But on the other hand, it may have just been the firing pin slamming into the primer as the bolt went home. What do you think?

[blaser.306]

The RCMP (Royal Canadian Mounted Police) Here in Canada Released a statement regarding an SKS that was imported I believe last year, it came from the Tula armory or one other I will try to find out more. At any rate it was imported and sold into the hands of a sport shooter that soon discovered that it was indeed full auto. The inspection paperwork for subsequent guns even shows pictures of what the fire controls look like with and without the semi auto disconnector ! I will see if I can locate any of the articles.
Inspection Protocol for SKS Carbines

General

1. This concerns the inspection of certain Russian made SKS carbines to determine if they are susceptible to firing in the full automatic mode.

2. The protocol is designed to be quick and simple and not involve the discharge of live ammunition. While revealing obvious potential for full automatic fire, there may be some conditions not detectable through this protocol. Suspect firearms should be isolated for more detailed testing.

3. The full automatic fire issue addressed by this protocol is caused by deficiencies in the trigger mechanism and is not related to previously reported instances caused by hardened grease or other foreign materials embedded in the bolt and interfering with the free movement of the firing pin.

4. One sample was inspected in October, 2014 which would fire only in the full automatic mode, was prone to shock discharge, and had an incomplete safety switch mechanism. Discharge of the carbine could be initiated simply by following the normal loading and cocking sequence. The full automatic fire capability could be migrated from one SKS carbine to another by moving the trigger mechanism thus establishing the problem lies solely in the trigger mechanism.

Scope

5. This protocol applies to Russian made SKS carbines manufactured in either the Tula or Izhevsk arsenal. These carbines are identified via the manufacturer's logo found on the upper rear surface of the receiver cover. Typical markings for the two main arsenals where the SKS carbine was manufactured are illustrated in figure 1 and figure 2. Note that the exact nature of the arsenal marks varies slightly from year to year.

Figure 1: Izhevsk arsenal marking

Figure 1: Izhevsk arsenal marking

Figure 2: Tula arsenal marking

Figure 2: Tula arsenal marking

6. This protocol applies to SKS carbines having the later (post 1951) simplified version of the trigger mechanism installed. The differences are depicted in figure 3.

7. The later version of the SKS trigger mechanism has an enlarged inspection hole (a); does not have the pin holes for mounting the semiautomatic disconnector (b); and the semiautomatic disconnector (c) is absent.

Figure 3: early (below) and later (above) SKS trigger mechanism

Figure 3: early (below) and later (above) SKS trigger mechanism

The Inspection Protocol

8. The inspection protocol is detailed in the table below. The same protocol is attached as Appendix A in a checklist format.


STEP

PROCEDURE

1 Prove the SKS carbine unloaded.
2 Degrease the SKS carbine as required.
3 Apply the safety switch and verify that the carbine cannot be discharged by pulling the trigger.
4 Verify the Russian origin of the SKS carbine.
5 Dissassemble the trigger mechanism and verify the presence of the later version of the trigger mechanism.
6 Reassemble the trigger mechanism.
7 Release the magazine to permit free movement of the bolt and bolt carrier.
8 Cock the mechanism gently restoring the bolt carrier to the forward and locked position.
9 Pointing the carbine in a safe direction, fire the mechanism, and keep the trigger pulled fully to the rear. A distinct "click" should be audible as the hammer falls forward.
10 Re-cock the action manually releasing the bolt carrier at the rearmost point permitting the bolt and bolt carrier to move without interference to the forward and locked position under the power of the return spring.
11 Fully release the trigger and immediately pull the trigger to the rear again. If the "click" of the hammer fall is heard, the firearm is operating in the semiautomatic mode. If no "click" is audible and there is no appreciable resistance to the rearward movement of the trigger, the carbine is most likely operating in the full automatic mode.
12 Carbines which appear to be operating in the full automatic mode are to be quarantined pending further testing.

Follow-up

9. The results of SKS carbine inspections are to be reported to the CFO office in the province or territory where the test was conducted.

10. Questions about the test protocol and related procedures are to be directed to the CFO's office.

Murray A. Smith
Manager, Specialized Firearms Support Services
RCMP Canadian Firearms Program

Appendix A

SKS Carbine Test Protocol

Serial number
Date of inspection
Business name
Name and signature of inspector
Comments


STEP

PROCEDURE

RESULTS and COMMENTS

1 Prove the SKS carbine unloaded.
2 Degrease the SKS carbine as required.
3 Apply the safety switch and verify that the carbine cannot be discharged by pulling the trigger.
4 Verify the Russian origin of the SKS carbine.
5 Dissassemble the trigger mechanism and verify the presence of the later version of the trigger mechanism.
6 Reassemble the trigger mechanism.
7 Release the magazine to permit free movement of the bolt and bolt carrier.
8 Cock the mechanism gently restoring the bolt carrier to the forward and locked position.
9 Pointing the carbine in a safe direction, fire the mechanism, and keep the trigger pulled fully to the rear. A distinct "click" should be audible as the hammer falls forward.
10 Re-cock the action manually releasing the bolt carrier at the rearmost point permitting the bolt and bolt carrier to move without interference to the forward and locked position under the power of the return spring.
11 Fully release the trigger and immediately pull the trigger to the rear again. If the "click" of the hammer fall is heard, the firearm is operating in the semiautomatic mode. If no "click" is audible and there is no appreciable resistance to the rearward movement of the trigger, the carbine is most likely operating in the full automatic mode.
12 Carbines which appear to be operating in the full automatic mode are to be quarantined pending further testing.

[DCM]

Does the firing pin move freely in the bolt?

[nhrifle]

Is the fire control group semi auto or does it have the original military parts in it? Remove the bolt from the carrier and make sure the firing pin doesn't stick in the "fire" position as this can cause a slam fire.

If I had to make a guess as to what happened, I would bet she experienced bump fire, where the recoil drives the rifle into the trigger finger and causes another round to go off. Some of the trigger groups put into import AKs to make them legal have such a light pull this is quite easily accomplished.

[milrifle]

The rifle is only semi. I'm not familiar with how the full auto one looks inside, but the safety has only two positions and passes a typical functional check in that with the trigger held to the rear and the action cycled, there is a "clunk" heard when the trigger is released and the disconnector releases the hammer and the sear catches it.

The firing pin does appear to move freely. It is certainly not stuck in the forward position. It does have a minute amount of drag on it, but like I say, it's not stuck in that position.

I had considered she might have bumped the trigger, but the primer on that second round did not have the deep impression of the firing pin that all the others have. It is barely dented. If she had pulled the trigger a second time, the primer would have the same firing pin impression as the others.

[blaser.306]

I tried to get the pics to load but would not, If you go to www.rcmpsksprotocol that will have pics with and without the semi auto disconnector and pin hole locations to be looking for.

[milrifle]

One other thing. It only did it the one time. We shot it several more times with no further incident (Although with never more than 5 rounds in the mag).

[aspangler]

A high primer can cause a slamfire. That may be what happened. I have seen a lot of the cheap ammo have high primers. Just sayin'.

[gew98]

Why all the allusion to the SKS ?. Any semi - especially the AK if it has a defective sear and or disconnector will cause a the hammer to drop when the bolt 'rams' home as it lets the hammer jump out and bammo. I have seen and handled import chinese SKS rifles with firing pins frozen with grease go full stupid when fired. I have experianced AR's and AK's with very worn internals that allowed full auto "type" fire of a less than controllable type. Replace those bits and you are good to go. Now I did see one type 68 SKS in a pile of imports at a show in PA 25 years ago .... could not believe it but it was what it was and walked out the door for less than $100 real quick .

[milrifle]

The rifle is brand new. Less than 100 rounds through it.

[1911cherry]

Yep sounds like a bump fire, a faulty sear, or trigger group wouldn't just act up once.

[gew98]

The rifle is brand new. Less than 100 rounds through it.

Brand new or not...it is an AK clone with likely less than quality fit parts . The AK is a bullet hose of peasant proportions. Such issues are not as rare as you might think with the semiauto US import variety.

[Petrol & Powder]

Without any pictures or other information I would vote that it's a firing pin problem. In fact, likely a lot of grease or other crud inside the bolt. The shallow firing pin strike on the second round seems to confirm the hammer is not striking the firing pin on the second shot but the pin is being held forward when the bolt closes.

[Multigunner]

I'll have to field strip my Romainiah AK to examine the pin and whether it has any method of preventing the firing pin from being driven forwards by inertia or stuck in place by fouling.
The AK bolt is a turn bolt loosely base on the M1 Carbine or Garand bolts. The Garand can have slam fires if the firing pin is damaged by contact with the rear of the receiever if a too hot round causes it to open too far and too fast.

Milspec primers aren't so easily set off by a light strike, sporting cartridge primers are more sensitive and more subject to slamfires and doubling.

[Lead Fred]

Its an AKS not an AK-47

Change primers to CCI 34 (LR) CCI 41 (SR), and watch your slam fires go away.

Mrs Fred's SKS has never had a slam fire, nor has the M1, M1a, AR-15, or any other semi-auto, but then Ive only ever used hard primers.

[1johnlb]

+1 on changing primers.

Floating firing pin and a thin primer cup equals Slamfires.

[milrifle]

Thanks guys. I'm leaning toward thin primers or stuck firing pin.

Thanks again. I appreciate all of your thoughts.

[HATCH]

All bolts are f/a on any of the ak style rifles. Its not illegal

Your issue can be one of a couple things.

Binding fire control group
Weak disconnect spring
Dirty firing pin channel

I have never shot reloads in my ak rifles but only one manufacturer made a spring loaded firing pin.
I suppose it is possible that you are getting a slam fire.

[Alexn20]

do you have a 3rd pin on that receiver?
Attachment 123919

Also take a look at your sear and disconnector. Many rifles just modify the full auto disconnector to a semi auto:
Attachment 123920


Based on your comment "The primer on that second round did not have the deep impression of the firing pin that all the others have. It is barely dented." I would say this was most likely a slamfire. Be careful and make sure that muzzle is always downrange!!

[milrifle]

Alexn20,

It does not have the third pin hole shown in your photo and the disconnector is like Type 1 in your diagram.