Help with stuck gas cylinder in Vz 52/57 rifle

[stickhunter]

I was breaking down a new-to-me Vz 52/57 rifle to give it a good cleaning and inspection before hitting the range. When I removed the piston connector (the C-shaped metal cover under the handguard), I noticed a small amount of light surface rust around the mouth of the gas cylinder. The rust came off easily with oil and a patch and didn't leave any pitting.

I proceeded to unscrew the lock nut (22mm) and the actuator (23mm) --- both came off easy. However, I was unable to move the gas cylinder, which I assume should slide along the barrel with hand pressure alone. I'm guessing that the corrosion I saw has fused the cylinder to the barrel.

I've put some drops off Breakfree around the outside and inside of the cylinder, so I'm hoping that will loosen up the works. I understand that the cylinder has close tolerances around the barrel, so I'm a bit concerned about damaging it if I try to move it with a brass drift. Any other suggestions?

For reference, the stuck part is the larger of the two bare-metal pieces in this picture:

 

[PerversPépère]

Use soaking with Kroil and try to TURN the part with a soft-jawed pipe wrench instead of tapping it out with a brass punch.
I think a small back and forth movement will break the bond sufficiently to allow Kroil to work its way inside and in-between the parts.
You may have to hold the adjustable sleeve with a big wescott wrench to avoid it moving.
Good luck!
PP.

 

[stickhunter]

Thanks PP... I totally missed the idea of twisting it to loosen it... that should lessen the chance of deforming the cylinder if use soft padded jaws.

 

[DaveGP]

Not an uncommon problem with that rifle - it's got to be cleaned well or it'll rust in place pronto.

 

[stickhunter]

Not an uncommon problem with that rifle - it's got to be cleaned well or it'll rust in place pronto.

Thankfully I have a large bottle of Gunzilla that should be up to the task.

Good news this evening... I got home and wrapped the cylinder with a piece of leather followed by a set of vise grips. Holding the receiver in my gun vise, I started twisting the vise grips and was able to break the cylinder loose without a lot of force and no damage. The area under the cylinder was blackened with carbon, but no rust, so I've wrapped it with a Gunzilla-dampened cloth to clean it up.

Thanks for the "twist" advice PP, that did the trick.

This is my first corrosive ammo shooter --- is it recommended to break down the gas system after every shooting session?