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-   -   AK74 Ejector Wear Concern (http://www.calguns.net/calgunforum/showthread.php?t=655162)

ArchStanton 12-11-2012 8:45 AM

AK74 Ejector Wear Concern
 
I joined the South Bay Rod and Gun club yesterday and shot just under 300 rounds of surplus 5.45 through my AK. It was a great feeling finally being able to zero my irons after building it last March at the San Diego Build party.

At home I noticed the ejector deformation and now I'm questioning my heat treatment.

http://i.imgur.com/EYMCi.jpg

Should I be concerned about this kind of wear?

Aaron707 12-11-2012 8:58 AM

Yes, redo the heat treatment on the ejector.It shouldn't be wearing at all. You may have annealed it too much. I typically heat the very corner with a mapp torch and dip it in oil without the annealing step after.

tujungatoes 12-11-2012 9:27 AM

Looks like you may have gotten it too hot on the tempering step. It's a simple fix. Just repeat the heat treating.

Jayruta 12-11-2012 12:21 PM

Bring it over tomorrow. We can redo it.

ArchStanton 12-11-2012 2:06 PM

Thanks for the replies.

Looks like I'll be fixing it tomorrow. I'll take it to the range afterwards and see how it took.

6mmintl 12-11-2012 2:26 PM

Did you hit it with a file to check heat treatment? if it skips over metal it 58-60 C Scale, if it digs in with resistence its lower, if it bite into metal and files easily it is way too soft.

ArchStanton 12-11-2012 9:14 PM

Quote:

Originally Posted by 6mmintl (Post 9897634)
Did you hit it with a file to check heat treatment? if it skips over metal it 58-60 C Scale, if it digs in with resistence its lower, if it bite into metal and files easily it is way too soft.

I did not hit it with a file. Though, I will soon to re-shape the tip before heat treating again.

Ryan in SD 12-12-2012 1:14 AM

One of my builds has the same amount of wear after about the same amount of rounds.
Im curious to see how far it will go before giving me problems.

ArchStanton 12-12-2012 2:24 AM

Quote:

Originally Posted by Ryan in SD (Post 9902159)
One of my builds has the same amount of wear after about the same amount of rounds.
Im curious to see how far it will go before giving me problems.

I had thought about doing that as well. Seeing as I still have the spare receiver from the build party.

I'll be fixing it, though. It's my only gun at the moment.

I'd be curious to see how long before it gives you problems.

Ryan in SD 12-12-2012 3:46 AM

Ok, Ill keep running it. Ill try to remember round count.

ArchStanton 12-25-2012 12:37 PM

Update:

Jayruta was able to help me weld a bead onto the ejector. After re-shaping and another heat treat, I shot another 240 rounds. This is what the ejector looks like now.

http://imgur.com/v7S77

Though not as bad as the first time, the metal is still deforming. Time for another round of heat treating?

nicoroshi 12-25-2012 12:45 PM

From the color of that ejector you got it too hot during the anneal step.
Color should be blue grey.
Progression of colors:
Brown
Purple
Blue
Blue grey (almost silver )
STOP!
From the looks of it you're a couple steps beyond that.

Jayruta 12-25-2012 6:55 PM

We did Ssop at blue grey... you can come back over and try it again if u want. I say roll with and see it mushrooms more. I have a some ejectors on a few builds that have a small mushroom but still function fine after over 2000 rounds and it has never gotten worse.

ArchStanton 12-25-2012 9:37 PM

Quote:

Originally Posted by Jayruta (Post 10015236)
We did Ssop at blue grey... you can come back over and try it again if u want. I say roll with and see it mushrooms more. I have a some ejectors on a few builds that have a small mushroom but still function fine after over 2000 rounds and it has never gotten worse.

Yeah dude I was thinking that. I checked the ejector twice during that last range session. It didn't seem to get any worse.

Looks like I have to go to the range again. Not disappointed at all.

69Mach1 12-25-2012 9:44 PM

I don't think you had a problem the first time. That "peening" is normal. My factory 5.45 rifle has an ejector that looks like that.

ArchStanton 12-25-2012 9:50 PM

Quote:

Originally Posted by 69Mach1 (Post 10016388)
I don't think you had a problem the first time. That "peening" is normal. My factory 5.45 rifle has an ejector that looks like that.

Good to know! I just want to be able to take this thing to an Appleseed and not worry about it.

ENTHUSIAST 12-25-2012 10:06 PM

Shoot the heck out of it if you have any issues at all let me know and we can get it squared away at the next Build Party.

Yemff 12-26-2012 12:17 AM

It could be a number of things. It could be that the quench was too slow(ideally less than 5s from orange to room temp), which would result in a softer steel where further tempering would yield no changes in hardness. If you are worried about it try annealing and tempering at lower temps, which may lead to quicker quenching. For the initial heat it is only necessary to heat the ejector above around 800 C (grey), but it doesn't hurt to heat up to higher temps, personally I wouldn't go above about 1000 C(orange). As far as tempering, try heating to around 300-500 C(brown/purple) , much higher than that may make you loose some hardness gained from quenching.

SJgunguy24 12-26-2012 11:47 PM

Quote:

Originally Posted by Yemff (Post 10017046)
It could be a number of things. It could be that the quench was too slow(ideally less than 5s from orange to room temp), which would result in a softer steel where further tempering would yield no changes in hardness. If you are worried about it try annealing and tempering at lower temps, which may lead to quicker quenching. For the initial heat it is only necessary to heat the ejector above around 800 C (grey), but it doesn't hurt to heat up to higher temps, personally I wouldn't go above about 1700 C(orange). As far as tempering, try heating to around 300-500 C(brown/purple) , much higher than that may make you loose some hardness gained from quenching.

You should change your temps here, 1700c is 3092f, that's molten temps there dude.


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