any way to tell if corrosive ammo was shot when at shop?

[Guest 1817ak47]

ok, long story short. I had taken my sks to a "gunsmith" due to occasional weak primer strikes even with soft primer winchester ammo. well I was suprised when they said what was there diagnoses problem, and they said the fired 20 rounds thru it. so I looked downed hte bore which I heavely oiled down to 100% prevent any corrsion while in storage, I checked to see if there was still heavy oil in the barrel, bore was dry and had quite a bit of rust in it:ugh:. so I ran hoppes thru it and then dry pad and then heavy oil for storage. I had green and blue steaking on the pads:confused:. I have only run wolf current production and wwb thru this and it is a unissued yugo sks. so the question again for those who are lost, I am curious if there is any way to tell if they tested it with corrosive and didn't cleaned/take care of it properly??

[Mark@Sea]

Yeah. If your bore looks like 9 miles of bad road - pits that look like craters - then they used corrosive and didn't clean it. If it cleaned up okay, no pitting, then they're just regular grade numbskulls, instead of super-duty rated.

'Green and Blue' is a normal indication. Rust is abnormal. I'd have words with them if it were mine. Really short words.

If the bore is pitted, make sure to clean the rest of the rifle, especially the bolt face.

[Garufa]

ok, long story short. I had taken my sks to a "gunsmith" due to occasional weak primer strikes even with soft primer winchester ammo. well I was suprised when they said what was there diagnoses problem, and they said the fired 20 rounds thru it. so I looked downed hte bore which I heavely oiled down to 100% prevent any corrsion while in storage, I checked to see if there was still heavy oil in the barrel, bore was dry and had quite a bit of rust in it:ugh:. so I ran hoppes thru it and then dry pad and then heavy oil for storage. I had green and blue steaking on the pads:confused:. I have only run wolf current production and wwb thru this and it is a unissued yugo sks. so the question again for those who are lost, I am curious if there is any way to tell if they tested it with corrosive and didn't cleaned/take care of it properly??

Green and blue streaking are normal with gun cleaning solvents. It's the chemicals working on the copper deposits (and brass cleaning rod).

Rust would look a lot different. Green & blue is not rust.

If you have weak primer strikes on a Yugo SKS that's an indication the bolt is full of cosmoline. Most likely packed full of it if "unissued". You need to get ALL of it out as it is a free-floating firing pin and the grease will cause all kinds of problems including slam-fires.

[Guest 1817ak47]

I thought the same about the bolt, and it made sense, so I disasembled the bolt completly and my soaking it in gasoline completely removed the cosmo. but I noticed bulged primers on some of my wwb brassthat I had and very faint strikes. from what little info I can gather sounds like apossible headspace issue. of my 4 22 rifle 1 22 pistol and a sks , mosin nagant, sks, xd9, bersa 380, never seen the colorful blue/green effect, just the black and lead grey color. my barrel had about 50% rust coverage when checking the bore today. he said they replaced the firing pin hammer

Edited January 12, 2010 by 1817ak47
left out checking the bores rust

[56FordGuy]

You thought about the cosmo before or after going to the gunsmith? I hope it was before, if the 'smith gave it back to you with the cosmo still in there I'd be very upset, on that basis alone. It's not that I'd expect him to detail clean my gun, but the cosmo would've been very related to the problem you're having.

Second, do you have a receipt that might list the exact part he said they replaced? The firing pin and hammer are two different parts.

[Guest 1817ak47]

"hammer spring replaced". the gun was cleaned up long before droped off and problem still persisted. and that took me many hours and lots of paper towels and q'tips etc. no he didn't give a detailed slip. just a verbal explanation. I had the bolt assembly completely apart to check the pin to see if it was bent etc long before droping it off and then reassembled it. the piston, trigger group, bolt and springs etc have all been carefully and obsessively cleaned till clean and then lightled oiled except the bore which was heavily oiled for corrosion prevention while in my storage.

[Guest 70below]

Sounds to me that if you have bulged primers and it appears you have "light" primer strikes, you actually have an overpressure situation that may be expanding the primer after strike and making the strike look light. I've seen reloads before that when reaching or exceeding maximum load the primer strikes will appear light because the pressure is actually pushing the pin mark back out.

That could be headspace issue. Does your sks have a bolt that is matching numbers to the gun? Usually in an SKS when you have a headspace issue its due to some sort of failure, or the bolt being swapped.

Edit: Also, its quite possible if your gunsmith isn't versed in SKS and AK rifles, that he used a SAAMI guage to check the headspace. That is not correct for most european guns, they need "Euro" or "CIP" type guages.

Edit #2: I just saw your bulged primers were with WWB.......US made 7.62x39 is made to the SAAMI spec and will headspace slightly differently than european ammo to my understanding due to the issue noted above. If all you had was light strikes with hard military type european/russian primers, then the light spring could correct that.

Edited January 12, 2010 by 70below

[Guest 1817ak47]

ok I failed to mention that it would have failure to fire and looking at the primers there was a light primer strike. that was why I would bring it in, I could sometime try to fire 2 or 3 times thesame cartidge and it wouldn't fire, pass it to my friendand bang first time everytime in his.

any light on this excessive bore corrosion??

[extremescene]

The firing pin should rattle freely when you shake the bolt. Avoid putting any oil in the firing pin channel. May be worth cleaning the firing pin channel once again. One blown primer and it is extremely filthy. Is your firing pin bent or mangled in any way?

Light strikes really could only be a few things and you've already eliminated the hammer spring. Without the receiver cover and recoil spring installed, dry fire and watch the hammer as it hits the firing pin. Does it strike cleanly? Is there wear at the top of the hammer that would indicate friction from rubbing on the recoil spring?

Headspace and firing pin protrusion and are the next things to check, both being extremely important for safety as well as functionality.

Edited January 12, 2010 by extremescene

[Guest gcrookston]

Being an unissued Yugo I'd have to look to the bolt / firing pin area being packed with dried grease 1st. Hammer/Hammer spring 2nd. I've had several Yugos brought to me over the years that wouldn't work and each time it was failure to remove all the cosmoline either from the bolt, trigger works or gas system. I would try a different lot of ammo for the bulged primer issue and thoroughly clean the gas system.

To remove cosmoline I have found the best thing to do is unbed the rifle and remove all organic components (stock, rubber, etc.), and liberally attack with brake cleaner, gasoline and a brass brushes.

[Guest 1817ak47]

I had soaked the bolt in gasoline shortly after I had gotten it. I also disasembled the bolt and removed the firing pin and inspected the whole assembly. the firing pin freely rattles back and forth. I have never have a hole poped in a primer though. just bulged primmers from WWBammo