bolt carriers what steel was used?

[M26PERSHING]

What kind of steel was used to make the bolt carriers? I'm trying to clean one up and its fruitless, its like depleted uranium or something?

[Greasemonkey]

What wrong with it? Rust, discolored, maybe a photo to help.

Far as I know, it's regular steel, like every other SKS. It should have a somewhat bright appearance, but not be polished to see your face reflective.

[Greatguns]

Some carriers were blued, BBQ painted, or a dull gray matte finish, while the bulk are polished steel. I'm assuming  a tempered 4140 as they would need to be hardened to a point to withstand the cycling movement and contact with the OP rod.
If yours is a dull gray it is made that way and should be correct to the rifle if it is all matching numbers so I wouldn't necessarily want to change it.

Sorry, just realized this is in the Romanian section. I was being too general being inclusive of all flavors as to the finish. Not real up on the finish on the Romanians other than the polished. Metalurgy should be the same though.

[Greasemonkey]

Yugoslavan, Albanian, Romanian, early/mid Chinese, non refurb Russians were usually bright finished.

Refurb Russian typically black or matte finish.

Some later Chinese, depending on factory were matte grey or a bead blasted style finish, a Chinese Israeli capture/middle eastern could be either a dark blued bolt carrier or standard bright finish.

A Romanian carrier 

[John Galt]

Hey guys,

I have a spectrum analyzer at work.  I will test my Romanian carrier and report back tomorrow.  This analysis will give me the type of steel along with its chemistry. 

[running-man]

Woo JG! 

Now that's how to tackle a problem, hit it head on with some science!

Is it a totally non-destructive test?  It won't mar up the carrier will it?  If it is, is it possible/easy to get an analysis of a receiver cover and a bolt too?  It would be interesting if they used the same steel for all components or if the different strength/bluing requirements had them use different types of steel with different hardenabilities in different components.

[John Galt]

The test is totally non-destructive.  I will test the bolt and the cover also.  I am not sure how the bluing will mess with the results, but I will give it a shot!

[Loose}{Cannon]

Great thread...     

[K-9]

Tag. Interesting.

Can we check wood types, too? LOL

[running-man]

Can we check wood types, too? LOL

The plan is to do just that once I get one additional sample.

Plan A is to get a Russian 'Arctic Birch' hardwood stock to send in for testing, but I haven't been able to find one on the cheap that I'm willing to cut up.  They are running $75+ shipping on eBay. 
Plan B would be to get a sub 15k ghost stock that looks very much like a Russian stock to send in.  I have no idea a if I have the nerve to cut up a ghost stock like that though.  The cost isn't the issue with these, its more the thought of forever losing a piece of history.  Oddly enough I have no such sentimental feelings about cutting up an XXX'd Russian stock.  (RM is a true Chinese fanboy after all, go figure eh?).
The most likely route is plan C which is to send my three known Chinese samples in with a native Romanian/Yugoslavian/Albanian or a Sinobanian-replacement stock if the search for the stocks in plans A/B proves to be fruitless. 

[Greasemonkey]

The plan is to do just that once I get one additional sample.

Plan A is to get a Russian 'Arctic Birch' hardwood stock to send in for testing, but I haven't been able to find one on the cheap that I'm willing to cut up.  They are running $75+ shipping on eBay. 
Plan B would be to get a sub 15k ghost stock that looks very much like a Russian stock to send in.  I have no idea a if I have the nerve to cut up a ghost stock like that though.  The cost isn't the issue with these, its more the thought of forever losing a piece of history.  Oddly enough I have no such sentimental feelings about cutting up an XXX'd Russian stock.  (RM is a true Chinese fanboy after all, go figure eh?).
The most likely route is plan C which is to send my three known Chinese samples in with a native Romanian/Yugoslavian/Albanian or a Sinobanian-replacement stock if the search for the stocks in plans A/B proves to be fruitless. 

You wanna Russian hardwood stock to sacrifice, I have one, aint really attached to it. I'll take a chainsaw, and just lop the buttstock off and send it to ya. I just sharpened the chain

Yeah, I'm being serious, PM me your address, a chunk of Russian stock will be on your doorstep in a week or so.

[running-man]

Now do you see why you scare me so much GM? 

I'll send you a PM.  We may get crucified by the 'real collectors' for thinking such blasphemy!

[M26PERSHING]

it is scratched to hell and back and not from its issued life. looks like someone used to the stop the grinder from spinning after the shut it off lol. I been using 80 up tp 320 to try to clean it up but damn, its some hard steel!

[Loose}{Cannon]

Guess we aint senting in the stovks I have?   

[John Galt]

The samples analyzed are numbers matching bolt carrier, bolt, and receiver cover, serial GN2942-1959

Bolt:  LA-4340           Carrier:  Ni-Hard         Cover:  LA-1215
Mo  .109                    Mo   .269                   Mo   .015
Ni   2.12                    Cu   .321                   Zn    .046
Fe   95.02                  Ni    3.75                   Cu    1.85
Mn  .429                    Fe    93.11                 Ni     .200
Cr   .944                    Mn   .314                   Fe     98.40
V    .209                    Cr    1.76                   Cr     .177

The composition can be effected by plated surfaces.  The carrier caused me some issues coming back as 97.57% chrome in all locations with the exception of a spot where the bolt and carrier have worn off the finish.  Also, I don't know how the bluing changes the results and I was too chicken to grind my bluing or chrome to try to get a better reading. 

The test itself does no damage to the object, it just needs a "pure" surface. 

[running-man]

4340 on the bolt.  Man, I would not have guessed that they would have used that steel for a gun bolt back in the late 50's!

Here's the composition of some modern ASTM spec A322-07 hot rolled 4340 I just got in:
C: 0.40%
Mo: 0.22%
Ni: 1.70%
Mn: 0.76%
Cr: 0.79%
V: 0.004%

Very similar to what you're seeing in your bolt.

Chrome plated carrier eh?  I always thought one of my Alby bolt carriers was *way* too shiny to be anything but chromed, but never could convince myself that those commies would actually do that to a bolt carrier.  I guess now we know.  And that's likely why M26 is having so much trouble with his carrier...he's trying to work with a Rc 60+ material.  Ridiculously hard coating.  Won't take to bluing at all either I'd suspect.

[running-man]

Guess we aint senting in the stovks I have?   

I've been waiting for you to drop $100 on a purdy Rusky stock! 

I have 3.  I think the limit per person is 5 in one calendar year.  Want to combine?  Lemme know and we'll get them out.

[John Galt]

running-man

The analyzer gun looks at composition and "matches" that composition to its internal library to come up with a material name.  I don't know if the steel is actually an older type that isn't in the library, but we can assume that 4340 would be a modern equivalent.

[Loose}{Cannon]

Guess we aint senting in the stovks I have?   

I've been waiting for you to drop $100 on a purdy Rusky stock! 

I have 3.  I think the limit per person is 5 in one calendar year.  Want to combine?  Lemme know and we'll get them out.

The Russian is the least of our concerns next to a ghost.  The entire reason I started that thread and found the place to dissect them is because the ghosts are seemingly different.  Guessing you dont recall me having several of the specimens we are sending in....

[Greasemonkey]

Now do you see why you scare me so much GM? 

I'll send you a PM.  We may get crucified by the 'real collectors' for thinking such blasphemy!

Bah the chainsaw works on bone and flesh as well....The stock dont match anyway, all these XXXX's and what not.  Want photos?