Marksman 2004 Seals

Greetings to the Group
I'm glad I found this forum, I have been looking for a group with the know how to fix my mistakes!

I have a Marksman 2004 with an old 1.5 x Bushnell Phantom mounted, and it is as accurate as a gun that looks like $300 (but cost $39.95 at wallyworld)!
Actually I am very pleased, It is a 1/2" gun at 25 feet in my basement range.

I have goofed up and oiled it at some point and now the seal is questionable.  It may take 20-30 cocking and dry fires until the seal catches and builds pressure (identified by the force needed to finish cocking, which goes from none to the normal stiff finish on closing the slide).

I have searched the Net over and see no sites for spare parts.  
The Chambers Gunmakers site yielded an exploded drawing (HW 40) and there seems to be only the main O-ring.
Does anyone know what the dimensions are and what is the material of manufacture?
Also what are your suggestions for lubrication on a gun like this or other single-pump pistols and rifles?
I have been considering purchase of some Daisy 953's for a local Boy Scout troop, and don't want to mess up the seals on any of those if I do.

Your help is appreciated in advance.
Thanks
Al Brown

[shadow]

I'm wondering if taking it apart and cleaning the oil out of the internal's would solve the problem?. I'm sure some of our great fellow member's will chime in and get this going in the right direction for you. Oh and Al,WELCOME TO GTA, this is a great place to be. Ed

[Rixtrix]

Hi, Al! Welcome to the greatest Airgun Forum. Friendly, fun and helpful. Good luck finding some help.

Ric G

[wyredvw]

did anyone ever respond to your questions.  If not I might have the info you need.  I just replaced all the seals in mine about 2 months ago.

[SDale]

I had the same problem with mine after about a week of shooting. I ended up taking it apart, cleaning out the valve, and deburring the air passage in the air chamber. I used all standard sized O-Rings from an off the shelf O-Ring kit. I don't remember the sizes, but they did work. The gun holds air and shoots just fine after a year now.

For lube, I lubed all the pivot points and metal to metal contact areas with moly paste. I lubed the valve and piston O-Ring with a VERY light coating of Silicone Shock Oil that I got off E-Bay (can also get it at hobby shops).Get the LIGHTEST that they have.  FPS went up slightly, but it took a few shots to get all the excess lube out of the cylinder and valve.


Hope that helps!