Quote Originally Posted by grieva View Post
.I have repaired the wood stock one which was very low on power(they are not noted for their power) it had two hammers in it I've no idea why but certainly did not help.Factory service manuals(copies) were available on evil bay at one time.
The M-1, when in good order, has good power for a BB gun. Anytime you have very low power, the 'pop" valve is not functioning. This valve was a Crosman design that held back the air moving from the compression chamber to the barrel until a certain pressure was met and then it would "pop" open. This was designed to increase the power of the BB gun. When it fails, the velocity goes to poop.

I have not worked on these guns. Have no idea if any shop in the US does either. Spare parts for this model have never been commonly available.

Note: from my experience, functionality has little, if anything, to do with the value. Guys want these as part of their collection not to shoot.