VZ58 piston rusted in place

[salmonriverfire]

I just bought my VZ58 last night. I never thought to check the piston. Everything else on the rifle looks great but as I started to disassemble it tonight I found the piston is stuck in place at the barrel end. I can see a slight orange tinge around the piston. I hit it with some oil and will keep soaking it but is there any other tips for freeing a stuck piston?

 

[p.Rundle]

Maybe taking a punch and hammering part of the piston that rests under the rear sight. Could get it to shift backwards a bit.

 

[salmonriverfire]

I tried that but it seems to be fully forward. Would it be reasonable to fire a round to see if that loosens it up?

 

[salmonriverfire]

I just got it. I was thinking you meant at the bolt end. I was able to get a punch in and slowly work it out. Thank's!

 

[p.Rundle]

No problem. I don't know a lot about all guns, but I know my Vz's. Run some really hot water through the gas port, and rub the piston head with a painters sponge from home depot. That'll clean it pretty well.

 

[salmonriverfire]

Okay cool I'll give that a try

 

[P0WERWAGON]

shoot it out.

 

[Mr.S]

edit

 

[P0WERWAGON]

the piston is stainless, the gas port is steel. the rust will not be able to hold the piston with all the gas pressure. may take a couple of rounds to bust it free

 

[bearhunter]

Put a couple of drops of Wipe Out bore cleaner on the piston. That stuff eats rust. WO will turn the rust in the blockage to mush. Then, as mentioned shoot it. Let it soak for an hour or so and good to go. Worked well on an M1 Carbine piston that had been frozen for years and the owner had been shooting it as a manual action. I will admit, that one took more than a couple of drops but it did start working by the next day. Then we managed to take the piston nut out and get the piston free enough to clean. He had shot some corrosive ammo.

 

[p.Rundle]

Put a couple of drops of Wipe Out bore cleaner on the piston. That stuff eats rust. WO will turn the rust in the blockage to mush. Then, as mentioned shoot it. Let it soak for an hour or so and good to go. Worked well on an M1 Carbine piston that had been frozen for years and the owner had been shooting it as a manual action. I will admit, that one took more than a couple of drops but it did start working by the next day. Then we managed to take the piston nut out and get the piston free enough to clean. He had shot some corrosive ammo.

.30 carbine was never made corrosive. That was part of the design because of the humidity of the pacific.

 

[Manteo97]

Original US Ordnance spec for the .30 carbine round was announced on Oct 1, 1940 and included a "non-corrosive primer", but no mention of powder type. For the first lot of 50,000 rounds, they were delivered March 1941, and the propellant was IMR 4227, with N/C primers. A second lot of 50,000 was ordered June 1941, with Hercules 2400. Note these dates are well before the US entry into WW II.

A third lot of 300,000 rounds was ordered in November 1941, just before the Pearl Harbour attack. It had a Dupont powder, "similar in characteristics" to IMR 4227.

Experiments with corrosive primers were done in 1943, but basically proved corrosive to both barrel and gas post/chamber area, resulting in non-functioning of the semi-auto action.

No mention in this source about non-corrosive powders, but I think a good assumption is that is corrosive primers were not in the original spec, and were not acceptable during the research, then corrosive propellants were not considered or used.

(Source of info: War Baby II, by Larry Ruth 1993)

 

[p.Rundle]

Original US Ordnance spec for the .30 carbine round was announced on Oct 1, 1940 and included a "non-corrosive primer", but no mention of powder type. For the first lot of 50,000 rounds, they were delivered March 1941, and the propellant was IMR 4227, with N/C primers. A second lot of 50,000 was ordered June 1941, with Hercules 2400. Note these dates are well before the US entry into WW II.

A third lot of 300,000 rounds was ordered in November 1941, just before the Pearl Harbour attack. It had a Dupont powder, "similar in characteristics" to IMR 4227.

Experiments with corrosive primers were done in 1943, but basically proved corrosive to both barrel and gas post/chamber area, resulting in non-functioning of the semi-auto action.

No mention in this source about non-corrosive powders, but I think a good assumption is that is corrosive primers were not in the original spec, and were not acceptable during the research, then corrosive propellants were not considered or used.

(Source of info: War Baby II, by Larry Ruth 1993)

Pretty sure there's no such thing as corrosive powder, unless it's black powder or maybe cordite. I was/am under the impression all corrosive elements came from the primer.

 

[fat tony]

French surplus .30 Carbine was once fairly common in Canada back in early 1980s. Maybe the French ammo was corrosive?

 

[crashcollins]

Pretty sure there's no such thing as corrosive powder, unless it's black powder or maybe cordite. I was/am under the impression all corrosive elements came from the primer.

There have been some reports of mildly corrosive powder in milsurp ammo that is otherwise noncorrosive. It's in the pages of CGN here somewhere from many many moons ago. Might have been a discussion in one of the dealer forums maybe, can't remember specifically.