Model 56 .22 - misfire, not the pin

[dhskier2]

My father in-law has a Model 56 .22 and is having some issues with it. He was a fire arms specialist for the police department and is now retired, he's no gunsmith, but he knows his stuff.
The issue-

Every 3-4 rounds he's getting a misfire. At first he thought it was the firing pin. Upon inspection he found the pin to be in good condition. He's looking for any suggestions as to what might be causing the misfire. What he would also like to get, is an exploded view of the firearm from a smithing manual. Any help will be greatly appreciated!

[Jim D]

Take a look at one of the mis-fired catridges. Is there a good solid indent from the firing pin? If there is, the problem may lie with the ammo. If there isn't, the firing pin spring may be too weak. Also, does the firing pin indent go all the way to the edge of the case?

-jim

[dhskier2]

Jim-

Thank you for the reply. I'm new here and have just finished admiring some of your restorations! WOW is all I can say.
I have been able to find a parts number for the pin spring (e-gunparts), I'll pass this info along. I'll ask him to take a picture of the cartridge for me. He's in Canada and I'm in Colorado. He spent some serious time cleaning the gun over the weekend and put a clip through it before he had another misrfire... now he's back to one - two misfire's a clip.