RH10 AK not working out of the box?

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Tortuga

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Story:

A friend of mine purchased an RH10. It's from Century Arms but, before you guys throw anything, this model is supposedly 100% imported from Romania. What's more, my friend waited until Rob Ski did a (very positive) review on it before she bought it. It's on youtube if anyone cares.

It's new out of the box, but it basically fails to extract or stovepipes every round. She's really upset because she paid like $900 for it, so I told her it probably needs to be lubed down a bit. I hit it pretty hard with Rem Oil and worked it into the action. We had 4 rounds go through and cycle correctly, at which point it went back to it's original problems. I hit it with more Rem Oil and still had the same results. We've put less than 50 rounds through it.

Problem:

It'll shoot a round but won't extract it, or it'll stovepipe it on the way out.

My Thoughts
I have seen this kind of performance on an older SKS that hadn't been shot in years, and it worked almost instantly once I hit it with some Hoppes 9 / Hoppes 9 Gun Grease. I only had Rem Oil with me so I'm not sure if that's going to be good enough or if I go buy Hoppes 9 again.

She was shooting Brown Bear Subsonic. I didn't have any other ammo with me, but I did try to bring some metal magazines with (she just had the plastic Pmag it came with). I hear those are supposed to be good mags, but I guess we don't know since the plastic Pmag was the only one that fit.

Can I be the hero here or do I have to explain to this girl that her firearm is junk? I remember having a similar experience with an old Masterpiece Arms Mac-11 I sold a few years ago, and all it really needed was "broken in." After about 100 rounds and a good cleaning it worked fine. I'm hoping that's the case here but honestly I'm kind of nervous for this girl since most of the semi-autos I've bought typically work 100% perfectly out of the box.

Here's the AK Operator's Union review. There's two on this rifle:
 
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Start messing with non-standard ammo and chaos often isn't far off IME. The gun was built to run standard velocity ammo. If the problem persists after the switch then there may be other issues in play.

The only thing that's weird to me is that subsonic ammo is higher grain so I'm wondering how it would fail to cycle under higher grain ammo. The only other thing I can think of is adjusting the gas block so it pushes back on the piston harder but I'm not sure.
 
The only thing that's weird to me is that subsonic ammo is higher grain so I'm wondering how it would fail to cycle under higher grain ammo. The only other thing I can think of is adjusting the gas block so it pushes back on the piston harder but I'm not sure.
It's failing because there is less powder in the case. The larger bullet simply means there is less space in the case (thus less powder). All things being equal, a heavier bullet for a given caliber travels slower than a lighter one. Except everything is NOT equal. There is also less powder. The bullet travels even slower and the amount of force pushing back on the gas system is reduced. In general, guns need to be tuned to shoot subsonic ammo and this is exacerbated in a gun that was never designed for subsonic ammo (like the AK). Can it work? Yeah, but there is no guarantee. Now if the gun fails to work using standard AK fodder, then you know you have a problem.
 
Am I reading correct your trying a rifle with subsonic ammo, and determining it doesn't work because of that? If so don't worry, very few rifles work with subsonic. Even 300AAC guns, built to function with subsonic ammo don't always do so reliably. AK's are very certainly not meant to. To make subsonic ammo work, you usually have a much heavier bullet, running faster powder. When the bullet passes the gas port, pressure is lower than would be with slower powder, and ejection is week. This is not because pressure drops off so much, but because with slower powder you have far more powder mass, and correspondant gas mass, which is what drives the piston. If I had any AK type that did function with subs I would be scared to shoot it with normal ammo, for fear of case head failure.
 
It's failing because there is less powder in the case. The larger bullet simply means there is less space in the case (thus less powder). All things being equal, a heavier bullet for a given caliber travels slower than a lighter one. Except everything is NOT equal. There is also less powder. The bullet travels even slower and the amount of force pushing back on the gas system is reduced. In general, guns need to be tuned to shoot subsonic ammo and this is exacerbated in a gun that was never designed for subsonic ammo (like the AK). Can it work? Yeah, but there is no guarantee. Now if the gun fails to work using standard AK fodder, then you know you have a problem.

Am I reading correct your trying a rifle with subsonic ammo, and determining it doesn't work because of that? If so don't worry, very few rifles work with subsonic. Even 300AAC guns, built to function with subsonic ammo don't always do so reliably. AK's are very certainly not meant to. To make subsonic ammo work, you usually have a much heavier bullet, running faster powder. When the bullet passes the gas port, pressure is lower than would be with slower powder, and ejection is week. This is not because pressure drops off so much, but because with slower powder you have far more powder mass, and correspondant gas mass, which is what drives the piston. If I had any AK type that did function with subs I would be scared to shoot it with normal ammo, for fear of case head failure.


I really hope you guys are right. I'm going to call my friend tomorrow morning and bring some old, regular Wolf ammo over and see what's up. If it works, I'll report back.
 
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Testing a gun with sub-sonic ammo might never produce any good results.

The gas pressure into the tiny gas port, pushing the piston etc, Must be a good bit lower than standard pressure.
 
Also, it wants disassembling and cleaning. If it's straight of the box from Romania, it may be gunned up with all sorts of muck. And then sub-sonic ammo.
 
With subsonic and a standard recoil spring not gonna work.
The ak does not have a spring loaded ejector like a ar. The ejector is actually on the left side rail. Ak has beefy extrator so its definitely doing its job because with full power ammo the amount of pressure on bcg is quite violent as it goes rearward the case knocked hard by the ejector, reason you see the shells kick out far.
Imo the rifle is short stroking. Depending on the gas port size which varries by nation, the Romania rifles are gassed just about right. In my experience the Chinese rifles had been overgassed while Bulgarian I have is right were I want it.
 
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we are right. Heavy for cal bullets cannot go as fast relative to their energy, therefore cannot produce the same energy (bolt thrust) or port pressure (cycling on AK). The easy way is to look at energy. A bullet must have the energy to cycle the bolt. A sub will have about 1/2 the energy in this cal. the faster the cal the less the amount. A 220 swift will have about 1/5. So even if unlocking is accomplished by the port, momentum of the bolt is insufficient, unless you get close to peak pressure. this is why your subs worked for a few. .
 
First thing, Century did not build this, they just open up the mag well to take 30rd mags after importing. Second thing, why is she running subsonic ammo? I bet it runs fine on standard ammo;)
 
You guys were correct. I talked to her today and she shot like 2 mags of wolf standard steel ammo with no problem. She was so happy she kissed me on the lips so I guess I owe you guys a big thank you :D
awesome, hows the accuracy? I have a friend who bought a Century WASR with a US barrel and receiver, and while it did not work reliably, accuracy was astonishing.
 
awesome, hows the accuracy? I have a friend who bought a Century WASR with a US barrel and receiver, and while it did not work reliably, accuracy was astonishing.

Honestly I was super amazed. I was only there for about 2 mags that she emptied but it was basically dead on at 100 yards. We were just plinking but she'll have to give you a full report sometime. Basically this version has a cold hammer forged chrome lined barrel so I'm expecting better accuracy than the traditional WASR-10 (Which I have personally seen shoot very respectable shot groups up to 250 meters).
 
I believe the barrels on these are a tad lighter weight then the WASR bbls, but both are cl hf barrels. Not sure what WASR doesn’t have a clhf bbl, to my knowledge, they all do. If Century built it, it is not a WASR....
 
Tortuga:
I'm glad that the new results are a very stark contrast.

Despite that really unfortunate, terrible first impression, the important thing is that you have one of the higher-quality imported brands, and didn't buy an I.O "AK" (no longer produced ! -due to many bad reports, videos, plus the infamous AKOU evaluations on Youtube), or a Century RAS.

JDGray: they are imported by Century, not manufactured by them.

Even Atlantic Firearms, a very reliable company, states that RH-10s are imported from Romania.
 
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Tortuga:
I'm glad that the new results are a very stark contrast.

Despite that really unfortunate, terrible first impression, the important thing is that you have one of the higher-quality imported brands, and didn't buy an I.O "AK" (no longer produced ! -due to many bad reports, videos, plus the infamous AKOU evaluations on Youtube), or a Century RAS.

JDGray: they are imported by Century, not manufactured by them.

Even Atlantic Firearms, a very reliable company, states that RH-10s are imported from Romania.
Agreed, I was questioning some comments about WASRs with US bbls and receivers, and the post about Century being the problem:)
 
As the others said a good cleaning is in order. When I got my RH10 the front end was full of metal shavings from when they opened up the mag well. Show her how to tear it down and clean it. Get some spare mags and ammo and she's off to the races.

WB
 
I have shot that same subsonic ammo in a couple of my rifles. Sometimes it will cycle, sometimes it won't. I wouldn't judge the rifle's performance based on that. Get a few boxes of standard ammo and try it out.
 
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