Modify my Crosman 1008 hammer spring - Where to buy a stronger one?

[Vic]

Hi

I did some modification on my old Crosman 1008. I took away the filter of air chamber by making gas flow easier. I decide to replace the original hammer spring with a stronger one. Can I find it at hardware store such as Homedepot? Does anyone know where to buy it? Or I decide to use superglue to glue some iron plate on the hammer to make it thicker, so it will hit the valve a bit longer and release more gas. Is it a good idea? I really worry to modify the valve spring because it may make the gun leaking gas.

Victor

[Syn]

Hi Vic, just in case you can't find your answer on this forum, try http://www.airgunforum.ca/forum/index.php

cheers

[TokyoSeven]

Unfortunetly, this is not a airgun forum so you may not recieve any information or support in regards to your inquiry.

[Burnsy]

Vic

I had the same idea as you but came up with a different solution which works fine on my 1008.

The idea of slightly increasing the distance that the valve is opened giving and increases the duration when the CO2 is allowed through the valve, into the barrel and therefore act upon the back of the pellet giving increased power…….! All sounds so simple…..or so I thought.

I disassembled the gun and looked at how the firing mech worked and noticed that after the hammer had been released it came to rest about 1mm away from the strike arm (which is raised to align with the actuator rod of the valve).

No mount of additional spring pressure would overcome this design.

So I came to the conclusion that I had to either;

a) devise a way of lengthening the actuator rod on the valve itself (I thought of machining a small cap to place over the rod end);

b) change the profile of the hammer so that it was not stopped by the casing and could swing a further 1mm forward, or;

c) modify the casing to allow the hammer to move further into the gun casing.

I opted for option C.

All you have to do is reduce the two blocks of plastic that prematurely stop the hammer. The one that stops the top edge of the hammer is 2mm thick and needs to be shaved down to 1mm and the other (more substantive) block actually stops the striking edge of the hammer. This one is about 4.8mm thick which I shaved to exactly 4mm (just in case).

This takes some VERY patient slicing with a craft knife (I used a scalpel with a No. 10 blade) which took me about an hour.

I also dealt with the annoying rattling and used liquid metal to cold weld the barrel to the gun. The barrel is loose fitting on this gun so it not only moves back and forth but can also move pitch within the housing.

This is what I put down to the reason why the gun was a little inaccurate when firing 20ft from being clamped in a vice (I was getting up to 5mm scatter) in my garage.

It now fires dead straight and unfortunately, straight through my old target so I am assuming that the power mod worked well.

I imagine that I will get less shots per cylinder but I’m happy with the results.

If anyone wants photo’s I have an unmodified one that I will also be upgrading soon so will take shots then if asked.

Oh and applying copperease (on the metal parts) and PTFE grease on the plastic trigger parts, my gun no longer has a snatchy trigger movement.

Happy pinking……!

Burnsy