Took my new gun out this morning, this happened three times

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[ARCHIVED THREAD] - Took my new gun out this morning, this happened three times

Posted: 5/4/2020 5:24:18 PM EDT

Ammo was PMC bronze steel case, out of a box of 20 I had three FTE’s.

Gun is a brand new M70AB2.

All three cases have a spot that looks like the lacquer may have melted:

The rims all look like this:

Prior to shooting it, I did clean the chamber and I punched the barrel with a bore snake.

I also greased the rails so the action is nice and smooth.

I’m hoping this was an issue with the PMC ammo, I’ll be trying out some Brown Bear later this week.

Posted: 5/4/2020 5:43:26 PM EDT

[#1]

That’s awful. Hopefully, other ammo works better. Did you have to tap it out from the front?

Posted: 5/4/2020 5:45:33 PM EDT

[#2]

Yep, I had a dowel in the truck cause this ain’t my first rodeo LOL

It took a good amount of force to pop them out

Posted: 5/4/2020 5:55:07 PM EDT

[#3]

Chamber defect maybe?

Posted: 5/4/2020 6:06:39 PM EDT

[#4]

Man I hope not, how would I check that?

I don’t know anyone around here with a reamer, will probably have to make a run down to PHX.

Posted: 5/4/2020 6:33:24 PM EDT

[#5]

By chance did you get the gun hot then leave a round chambered for awhile and then fired that round?

Posted: 5/4/2020 6:44:54 PM EDT

[#6]

Negative

I loaded 20 rounds in a mag and began firing, and it wasn’t very rapidly either.

The cases that got stuck were chambered for a couple of seconds, max.

Posted: 5/4/2020 6:54:23 PM EDT

[#7]

Do you have calipers to measure the cartridge diameters?

Posted: 5/4/2020 7:04:01 PM EDT

[#8]

I’ve got calipers at the shop, I can do some measuring tomorrow

Posted: 5/4/2020 7:15:43 PM EDT

[#9]

My *guess* is a slightly rough area in the chamber.
My second *guess* is that after a couple of hundred rounds it works just fine.

I would use brass cased ammo to break it in though ... maybe just superstition ... but I have never 100% trusted steel cases.

Posted: 5/4/2020 8:29:57 PM EDT

[#10]

Do you have the other cases ?

Are the " melted lacquer" marks on the cases located in the same place if reference by the damage on the rims?

If so that would suggest a chamber issue.

Posted: 5/4/2020 10:00:38 PM EDT

[#11]

I’d take a hard look at the chamber for any obvious defects just to be on the safe side. With that being said, I don’t think I’ve ever had a spent casing with that oval shaped mark that looks almost like the coating on the steel case melted and stuck to the chamber.

Posted: 5/4/2020 11:22:40 PM EDT

[#12]

The spots where the lacquer seems to have melted are not all the same in relationship to the chunks missing from the extractor.

They are all shaped differently too.

Weird thing is, the first case to get stuck, which was the fifth round fired, had the biggest spot.

I’m going to order a few boxes of brass case ammo, will see how it extracts.

Posted: 5/5/2020 12:00:40 AM EDT

[#13]

Have you fired any of that ammo in a different gun? Hopefully it's just the ammo.

Posted: 5/5/2020 12:54:27 AM EDT

[#14]

I did not, I only had one box of that stuff.

I did buy 500 rounds of Brown Bear but I’m thinking I should try some brass cases to see what happens.

Posted: 5/5/2020 1:16:59 AM EDT

[#15]

If this was a new gun I would be contacting the manufacturer or dealer, unless there was something obviously wrong with the ammo. Really think it's a chamber problem may need a reamer or at least polishing the chamber.
Have you tried cycling some rounds through it without firing them to see if they hang up or fail to chamber completely?

Posted: 5/5/2020 7:36:17 AM EDT

[#16]

What does the chamber look like shining a flashlight inside? None chrome lined barrel may just have a rough spot. I would try different ammo. David

Posted: 5/5/2020 8:43:44 AM EDT

[#17]

get a chamber brush and scrub the ever loving shit outta it. I mean maybe even put a rod on there and attach to a drill and scrub that chamber.

Posted: 5/5/2020 9:03:28 AM EDT

[#18]

I would definitely want to take a look at that chamber - also the extractor, which may have been damaged by having to rip the rims off steel cases because the case would not extract. Clean the chamber and bore normally, then use an inspection mirror to see the chamber - something is definitely going on there.
I wouldn't waste any more ammo to see what happens - if you try brass-case it'll just be easier to rip the rim off.

Posted: 5/5/2020 10:37:18 AM EDT

[#19]

I have NEVER seen a steel case from PMC.

That looks like Chinese ammo that someone stuck in a PMC box.

Posted: 5/5/2020 10:50:40 AM EDT

[#20]

Wait - is that possibly brass-case? If it is, it would explain why the extractor tore the head off when there was a problem in the chamber making for hard extraction. The odd mark on the cases notwithstanding, it could just be a contaminated, slightly large chamber and the brass case over-expanding and sticking. That mark still has to be explained, though.

Posted: 5/5/2020 11:01:28 AM EDT

[#21]

Well I’ll be damned, you’re right.

I just checked the headstamps, I see “351 93”.

Apparently this was Chinese ammo.

I take it this stuff is garbage?

Posted: 5/5/2020 11:54:22 AM EDT

[#22]

No, Actually it is some of the best ammo out there in my experience.

I don't know why it's causing you trouble except maybe it wasn't stored right and has developed corrosion under the coating or on the inside of the cases.

I have shot that same headstamp out of my MAK-90 with absolutely no problems whatsoever.

Just pointing out that it wasn't PMC's fault. Could still be a rusty spot on the chamber wall or something.

Posted: 5/5/2020 1:17:32 PM EDT

[#23]

Weird.

I stopped at my spot on my way here and fired off three full mags of Brown Bear and didn't have a single failure.

You're probably right about that ammo not being stored right, I'm assuming the 93 means it was made in 1993?

I doubt it was kept in a sealed container.

Anyway I'm relieved it's not the gun.

Posted: 5/5/2020 1:59:35 PM EDT

[#24]

Yes, made in 1993.

Chinese ammo was banned from U.S. import in late 1993 or early 1994.

Just out of curiosity where did you get that box of ammo?

I hope not from a gun shop?

It's not real good practice to put random ammo in a different box than it actually is.

(I mean I do it ALL the time, but I also reload and need the boxes to store it in. And I don't sell it either)

Posted: 5/5/2020 2:17:16 PM EDT

[#25]

Got it from a buddy a few months ago, he was cleaning out his safe and gave me those rounds since he didn't have an SKS anymore.

He also gave me some Lake City 7.62x51 match ammo, I suppose I better check the headstamps on those LOL

Posted: 5/5/2020 3:33:38 PM EDT

[#26]

Okay, you have fired corrosive ammo so you need to properly clean that rifle ASAP. All metal parts inside and out, to put it in a nutshell. the best thing to use is an emulsion of Ballistol and hot water. Put it in a spray bottle and use a smaller paint brush to work it around. Rinse with more of the mixture. At this point you are protected and can use straight Ballistol as your CLP after it dries out.

Posted: 5/5/2020 3:48:38 PM EDT

[#27]

You sure about that?

When researching the 351/93 headstamp I came across this thread:

https://www.ar15.com/forums/ak-47/Is_This_Ammo_Corrisive___/54-120103/

I also pulled up some pictures of the boxes that this exact ammo came out of, they are labeled as non-corrosive.

Posted: 5/5/2020 6:12:35 PM EDT

[#28]

Quote History

Originally Posted By Model603:
You sure about that?

When researching the 351/93 headstamp I came across this thread:

https://www.ar15.com/forums/ak-47/Is_This_Ammo_Corrisive___/54-120103/

I also pulled up some pictures of the boxes that this exact ammo came out of, they are labeled as non-corrosive.

View Quote

Do you trust the Chinese

Posted: 5/5/2020 6:21:37 PM EDT

[#29]

I don’t trust anyone

I’ll give it a good cleaning tonight

Posted: 5/5/2020 6:34:32 PM EDT

[#30]

Quote History

Originally Posted By PhilipPeake:
My *guess* is a slightly rough area in the chamber.
My second *guess* is that after a couple of hundred rounds it works just fine.

I would use brass cased ammo to break it in though ... maybe just superstition ... but I have never 100% trusted steel cases.

View Quote

The platform is designed for steel case.

But it’s a Yugo and M67 isn’t.

Posted: 5/6/2020 9:19:01 AM EDT

[#31]

I'll say it again, get a bore and scrub that bore real good. I had a sticky bore once and this did the trick.

Posted: 5/6/2020 10:42:13 PM EDT

[#32]

The rifle looked very dry inside but that may affect the operation only because it indicates a similar condition throughout. Possibly the ammo is not corrosive but there were problems with corrosive primers in non-corrosive-labled ammo in those days - not worth the risk. The ammo is definitely 'bad' but I'm trying to think of how it could be too weak to work the gun but at the same time strong enough to power the extractor to rip the case head. Could it get too powerful from any kind of improper storage? I don't know if that would explain it or not - seems like it would make the case come out better, but then the head wouldn't get ripped off. There must be a problem in the chamber even if its only contamination/lack of cleaning. I don't leave my bores and chambers oily but I condition them with whatever I'm using as a CLP and then dry-patch them.

Posted: 5/6/2020 11:20:01 PM EDT

[#33]

The cases may have been damaged when I “mortared” the rifle to get the bolt unstuck.

It definitely was dry in there, I greased up the rails but that’s all I did as far as lubing it.

I didn’t have any problems at all with the Brown Bear, I’m sticking with ammo that I know works.

Posted: 5/7/2020 3:04:01 AM EDT

[#34]

head space..

check it.

Posted: 5/7/2020 1:33:27 PM EDT

[#35]

Chinese ammo is garbage but has a legendary status attached to it because it was once cheap, plentiful and steel core, and is now banned from import. If Brown Bear worked for you then I doubt the rifle is the problem.

Posted: 5/7/2020 1:42:56 PM EDT

[#36]

You should NEVER have a stuck case on an AK or any 7.62x39 gun. It is a mandrel fit taper case. The tiniest tap should pop it loose. I'd review your extractor and extractor spring too. Ensure it has no chips and spring is nice and stiff and check the chamber for defects.

Different ammo may make a difference, but at the end of the day skinnies are using crap surplus ammo hauled out of a Russian bunker from the 70's all day every day in Dumpster-Fire-O'Stan.

Posted: 5/7/2020 2:01:48 PM EDT

[#37]

Quote History

Originally Posted By 1saxman:
Okay, you have fired corrosive ammo so you need to properly clean that rifle ASAP. All metal parts inside and out, to put it in a nutshell. the best thing to use is an emulsion of Ballistol and hot water. Put it in a spray bottle and use a smaller paint brush to work it around. Rinse with more of the mixture. At this point you are protected and can use straight Ballistol as your CLP after it dries out.

View Quote

Ballistol is great stuff....if you can't find any, an old trick for shooting corrosive ammo is to keep as bottle of Windex window cleaner in with your shooting stuff, and really hose down the gun good at the range before you head home. Apparently the Windex dissolves most of the corrosive salts. But Hoppes does the same thing, it is just more expensive.

The oldest thing for cleaning up after corrosive ammo is a bucket of the hottest water you can get and some dish soap...put the muzzle in the bucket of soapy water and scrub the living hell out of the bore.

Posted: 5/7/2020 6:42:07 PM EDT

[#38]

Quote History

Originally Posted By Minuteman556:
You should NEVER have a stuck case on an AK or any 7.62x39 gun. It is a mandrel fit taper case. The tiniest tap should pop it loose. I'd review your extractor and extractor spring too. Ensure it has no chips and spring is nice and stiff and check the chamber for defects.

Different ammo may make a difference, but at the end of the day skinnies are using crap surplus ammo hauled out of a Russian bunker from the 70's all day every day in Dumpster-Fire-O'Stan.

View Quote

It's a brand new rifle and in my experience Zastavas are built tight. I would inspect as others have suggested but keep running it to break it in with a few hundred rounds.

Posted: 5/7/2020 10:51:41 PM EDT

[#39]

I’ll have to find someone with gauges so I can check the headspace.

For now I’m just going to keep feeding it Brown Bear and I’ll be passing on any random Chinese ammo.

Posted: 5/10/2020 10:31:54 AM EDT

[#40]

OP, I have a M70AB2, and haven’t had this issue.

If you live close to the Mesa, AZ area, I’m willing offer what help I can. Maybe compare M70’s?

I’m definitely not an expert on the AKM platform, but I’ve learned a few things.

Hopefully it’s just some bad wuhan ammo you came across & not the gun. Yugos are great AK’s !

Posted: 5/10/2020 1:16:02 PM EDT

[#41]

I appreciate the offer but I think the rifle is fine.

I’ve taken it out a couple more times and have put a little over 300 rounds of Brown Bear through it without a single failure.

I’m chalking this up to some bad Chinese ammo that probably wasn’t stored properly.

The damaged cases look weird, it almost looks like a casting where the chunks were ripped off by the extractor.

I’m going to try some different brands of ammo just to be sure but I think the rifle is good to go.

Posted: 5/10/2020 6:43:29 PM EDT

[#42]

Let's clear up this old wives tale about corrosive salt. There is NO deactivating the salts with another chemical. The only way to get rid of the salts is to wash them away.

The easiest way to accomplish this tack is with boiling hot water. You can boil a pot and clean the field stripped parts in it. Boil for 5-10 minutes, then remove and let them cool. Clean as normal.

For the rest of the rifle, take it outside and pour hot water down the receiver and down the barrel. You can use a funnel to make sure the water goes down the barrel. Let the gun dry. Use a heat gun if any spots remain. Then clean as normal.

I've done this on a PSL and Mosin-Nagant's for several thousand rounds and my guns are pristine.

Good luck!

Posted: 5/12/2020 5:10:45 PM EDT

[#43]

Ballistol and water emulsion is better than boiling water because:
1. No boiling water to deal with yourself, and no boiling water on the gun which is a great de-greaser, right at the time you don't want to strip oil off parts that may be subject to corrosion.
2. You can use hot tap water to make your Ballistol emulsion without having to deal with boiling water but cool water works the same. The Ballistol emulsion has a higher ph than either Ballistol or the water alone. An alkaline solution is what you want when removing corrosive salts.
3. The Ballistol emulsion dissolves and washes away the corrosive salts while it carries Ballistol into every seam/joint that water can penetrate.
4. When you're finished washing the whole gun inside and out with the emulsion, you can blow it out with air, use mild heat like a hair dryer or just set it aside. The water evaporates, leaving behind the Ballistol protection, and this is in every place on the gun that got wet.
5. The gun is now cleaned and protected from the corrosive salts and ordinary rust. It can stay like this indefinitely but the second step is to use straight Ballistol as your CLP and clean the gun as you normally would. Ordinarily you would do this within a day or two and before shooting again.

You can use any method you wish, but if you want to do this the right way and have utmost confidence that the gun is not rusting, you have to use this method. If you don't use corrosive ammo, its really easy - just clean the gun with straight Ballistol, wipe off the excess and you're done.

Posted: 5/12/2020 6:45:29 PM EDT

[#44]

Having shot thousands and thousands of corrosive rounds the past 15 years I have to ask you guys talking about water and soap and ballistol and all that shit...is there any carbon left on the rifle after you do that?

You realize the corrosive salts are in the carbon deposited on the gun. The carbon doesn't magically come off when water is applied to it...so where do you think the salt is going to stay?

Posted: 5/12/2020 8:07:20 PM EDT

[#45]

Edit:

I just just use hot water then clean as normal. No corrosion yet.

Posted: 5/12/2020 8:22:11 PM EDT

[#46]

Quote History

Quoted:
Edit:

I just just use hot water then clean as normal. No corrosion yet.

View Quote

Same here.

Posted: 5/12/2020 8:59:47 PM EDT

[#47]

Quote History

Quoted:
I don't trust anyone

I'll give it a good cleaning tonight

View Quote

When I built my AR74 I had to take a chamber brush and 'polish' the chamber a little. Took a couple of times. Chucked it in the drill and ran it for a minute or so each time.