single shot 12 ga misfires intermitantly

[drednekhunter38]

hello, my stepfather is having problems with a single shot that i bought him for his birthday. the gun is a stevens model 9478 12 ga. the problem is that when he pulls the hammer back and squeezes the trigger sometimes it just goes click instead of boom. it does not happen all of the time and it does not seem to discriminate between brands of shells as it has done this with both winchester turkey shells and remington high brass. is there any kind of adjustment that we could possibly do to the firing pin or possibly the hammer spring? any help would be greatly appreciated.

 

[woodfiend]

I was thinking that the gun may need some hammer/spring work. It sounds like it gets caught sometimes and hangs up. Maybe some polishing or better fitting?

 

[gb6491]

In addition to what woodfiend suggests; try pushing on the firing pin from the hammer side. It is spring loaded, so you should feel tension when pushing on it. It should also comeback freely to it's original position when released. That position should also be with the pin high enough for a good hammer strike.
Parts diagram available here: http://www.e-gunparts.com/productschem.asp?chrMasterModel=089Zz9478
Regards,
Greg

 

[rcmodel]

Several things could cause that.

*Dirt & dried oil in front of the firing pin.
*Broken or stacked up firing pin retractor spring.

Check if the firing pin moves freely, and is spring loaded to the rear. Oil it with light oil.

*Weak hammer coil spring.
Replace it.

Here is a parts list & schematic of the gun, and spring kits are available.

http://www.gun-parts.com/savageshotgun/

rcmodel

 

[drednekhunter38]

i placed my finger over the hole where the firing pin protrudes to strike the primer and dry fired it. it definately was coming out, but then again it was an intermitant problem. and i had already oiled the firing pinand hammer assembly. thanks for the help and links guys. i'll probably replace the hammer spring and firing pin spring before spring gobbler season.

 

[Riss]

The firing pin should not be oiled. Oil will only attract more dirt and eventually gum it up. If anything is used, maybe a dry teflon lube or powdered graphite, but no oil.