So I've got about 500 rounds through my Chinese Norinco/Sino Defense 7.62 AKM, during cleaning I found a weird wear mark on a part which I think is responsible to initiate the rotation of the bolt when it locks.  

This is my only AK so I wonder if this is normal wear or if I should be concerned about it. I mean if this keeps getting worse would the bolt start to fail to fully go into battery eventually?  
The bolt stem seems super hard and its pretty unimpressed by that contact, its barely shiny where it hits that spot in the receiver.

How do your AK's look?

(And yes, I like to lube my guns A LOT. Everything is better with lube.   )

Lube yes, pack with grease like a wheel bearing....ummmm....lol!

Doesn't look bad to me, but there are guys on here with more experience than me who will chime in i'm sure.

Pretty normal. What goes on in an AK is that there are two camming surfaces for the bolt: the camming channel in the bolt carrier, and the camming ramp which is part of the bullet guide - this is where you're looking in your pic.

The camming ramp usually kick starts the initial rotation of the bolt and then the camming channel in the carrier completes the rest of the job of bolt rotation as the carrier moves forward.

Considering that you have several different independently machined surfaces in play together, they almost never completely mesh together seamlessly 100% out of the box, and so there is some wear-in that occurs on all of these surfaces (including the camming lugs on the bolt itself) until the timing of all of these surfaces is in complete agreement. Once that is achieved, the visible wear will typically stop and stay that way.

if you've already put 500rd through it, you're probably most of the way there to establishing that initial wear-in.

also IMO that is way too much grease and you've greased a lot of areas that don't even do anything. I prefer to not have the receiver get gunked up with grease and powder. I just keep an AK dry except for a drop of oil in the bolt carrier camming channel, a drop on the bolt stem, a drop on both the bolt carrier rails, assemble it and rack the carrier a few times. done. I had a time where I tried greasing AKs but the grease would quickly turn into an abrasive, smelly paste with all the blowback of gas into the receiver.

So the parts are just trying to get to know each other? Now that's something I totally understand, developing relationships takes time!

I hope that's the case - but what I find interesting is that it seems like the bolt is SUPER hard, there is not a hint of a wear mark on it compared to the receiver. For some reason I expected both parts to be roughly of equal hardness.

As for the oil, I don't put oil in the whole rifle but just the cam track of the bolt carrier, the rails the carrier rides on, the bolt stem and locking lug area of the receiver. Its just covered like that because I just shot it, the oil gets flung absolutely everywhere!

I believe this camming surface, aside from initiating bolt rotation during clambering, also acts as a force multiplier during extraction.  This is the AK's "primary extraction."  A lot of other weapons have similar mechanical arrangements in order to multiply extraction force, reduce strain rate, or both.

Stick an empty steel case in the chamber, and let the bolt fly home on it, then try to get it out of there.  You might need a deadblow hammer to smack the charging handle hard enough to do so.  The fired steel case is larger than the chamber when both are under ambient conditions.

That is the force required for the gun to extract a cold-worked steel case for every shot.  A brass case basically just falls out of there, will nil resistance.

Maybe thats the issue, the AK was made with steel cases in mind but I am only running premium brass through it. Maybe that's why I get insane ejection at 1'o clock despite the rifle not being severly overgassed.

When I take her out I only feed her the best

A 7.62x39 case does not need gigantic forces to extract in an AK or any other platform. The tapered case is the real secret sauce in the AK's legendary reliability. Coupled with a chrome-lined chamber it's hard to beat.

A straight-walled case when extracting, has to drag the entire length of the chamber to remove, on a tapered case, the instant it unlocks a tiny fraction of an inch, there is no more drag.

The only time i've had a steel-case round get stuck, was in an AR, and that was a .223 round. Never had a failure to extract 7.62x39 even in an AR.

Put an empty steel case in the chamber and let the bolt fly home.

Straight-walled revolver cases made of brass basically fall out with nil resistance.

The seemingly excessive taper of the 7.62x39 case is necessary for this reason.

You will get insane ejection with almost any properly gassed AK. It's a design that's meant to eject cases under absolutely any circumstances - whether dirty or well below freezing - and reusing the spent cases was obviously not a design goal.

If it bothers you, you can tune the ejection with the KNS adjustable piston or a stiffer recoil spring like Wolff XP. The KNS piston gives you multiple settings while the XP spring has no adjustment.  Some guys who reload for AKs use the KNS piston so that they can reduce the ejection strength. If your cases are getting dented during ejection, usually reducing the ejection strength will cut down or eliminate the damage to ejected cases - and you will actually be able to find them once they aren't flying 25m away with every shot.

That's actually pretty normal, though - the design is meant to eject cases under any circumstances, whether it's dirty or freezing cold. If it's bothering you, you could try tuning the ejection with a KNS adjustable piston or a stiffer recoil spring like the Wolff XP. Some reloaders use the KNS piston to reduce ejection strength and prevent case damage. That way, you can actually find your cases after shooting instead of having them fly off into the distance!

Excess lube on non bearing surfaces only gathers crud….

If there is a wear mark, lube it.  Bolt contact surface where it rides the rails, contacts the hammer, etc.  If it isn’t in contact, make sure it had some oil, but wipe it off.  Just enough so it doesn’t rust, not enough for actual lubrication needs like a contact surface gets…

^^^^this.gif

My rule of thumb has always been this: Lube the inside of your gun, to the same degree you lube the outside. We all put a tiny bit of oil on a rag and wipe down the barrel and receiver as part of cleaning right? But only enough to make it shine a bit, just a tiny surface coat to resist rust. That's all the inside needs too.

You leave gobs of grease in the bolt carrier, on the rails, on the bolt, on the trigger components, and you're just gumming up the works. Pools of oil, same thing.

Holy cow, that thing is as expensive as it looks sophisticated. I feel installing that piston in an AK would be like giving a tractor a race car radiator.

On the other hand it would probably help prevent my brass cases getting dinged up by the dust cover to the point they cannot be reloaded. Huh might be worth it.


My shooting buddies tell me that all the time yet I never experience any malfunctions with my guns and they look a lot more pristine than theirs even with similar round counts. I have a Glock with an aftermarket barrel in it, gold nitrate finish and I lube the barrel after every trip to the range. 2000 rounds through it and the finish looks like new while my buddies Glocks have worn the finish on the barrels after an equal amount of rounds through them.
The gunk that builds up does not seem to accumulate to the point it results in jams, not in a single range trip anyway. I always clean and re-lube my guns after every session.

I'll keep my guns wet!

2000 rounds isn’t much at all.  Probably what I averaged thru a Glock every month or two, for many years.  

I have seen repeatedly where excess or incorrect lube has fucked up a firearm’s function.  I am an instructor and armorer who dealt with problems, maintenance, logistics, etc.  It happens.  Problems happen a lot more with folks who do too much lube, or not enough, or who lube things that don’t move or contact other things…  

And you misunderstood what I said if you think that I would not oil the contact/rub areas of a pistol barrel.  If it rubs, lube it!  So that does mean where a pistol barrel rubs the slide.  Glock only recommends a few drops of oil on the pistol, but that is one of the spots that needs it.  

But I think you don’t know what needs lube and what does not.  Just slathering stuff all over is no way to do it, especially with thicker oils or grease.

I know folks who didn’t listen to good advice about how to clean and lube their guns, their stuff always had issues.  One guy I had to clear his striker channel (Glock) because he rarely cleaned it, and when he did he let oil get down in the striker channel- so it didn’t work.  I cleaned it out, chastised him about it, and guess what - couple years later he got off only one round in an incident before his gun jammed on him…. People who over lube their Glocks are always the ones who clog the channel and end up with a non-firing pistol.

The flip side is folks letting their AR’s dry out, which absolutely is no good.  Many classes I would just squirt lube onto the BCGs before starting the day, or at lunch, to just prevent problems from those folks.  But the AR is a great design that sheds excess lube when firing, and we were going to do a full tear down at the end of the day.  

TLDR- Learn what needs lubed, and what doesn’t.

Not sure what gives people suddenly the idea I don't know how my firearms work and where the friction areas are. I don't dip my rifles and pistols into a barrel of oil, I do lube the friction points but as firearms cycle violently they tend to spray lubricant everywhere inside the action.


Ok but what I am saying is that 2000 rounds was enough to wear the finish of the barrel of my friends new Glock while I was lubing the outside of the barrel after every trip to the range and it looks like new, basically.

the parts will friction fit. I shoot my AKs and even my ARs dry. The only lube I use is a little bit of lithium grease on my M16