Crosman 600 finish

[callumej]

Hi guys, I have a Crosman 600 question that I’m hoping someone could help with.
At what point did the finish of the pistol change from deep black to a bluish grey?
I have a 600 that I’m rebuilding which appears to be made up of parts from different variants. I’m trying to decide which variant to build it up as, keeping it as original as possible. The frame is the blue-grey one. 
Thank  you.

[SOCEY600]

I’ve noticed that if I ever see a bluish grey one, then it’s always the last variant with the plunger piercing cap.

[callumej]

Thank you Tom, that’s useful to know. The pistol I have has the 2nd variant setup (capsule inserted neck first) and brass valve body, but undrilled blue grey frame.

[SOCEY600]

So Callum, I’ve never looked closely at a second variant model. The way I understand it, is that the steel tube is not pressurized. The frame and steel tube are drilled so that a screw can secure the o-ring/piercing assembly inside the steel tube. The way you describe your gun, I don’t see how the piercing assembly could be secured if the frame is not drilled. Maybe someone damaged the original screw cap and replaced it with the second variant cap, with the hole in the middle.
With the cap removed, if you look down the steel tube, do you see a piercing pin?

[oldair]

The 'hole-in-cap' version was made both ways: with and without the small screw ahead of the trigger guard.  That screw has no apparent purpose; the pierce pin and cartridge sealing are threaded into the valve assembly.  Years ago I struggled to get the little screw to seal and vowed never to tackle one again.

Don R.