Have a 52C that regularly fails to fire. After closing the bolt on a live round the trigger is pulled but the firing pin does not strike the cartridge. I thought at first it was a manual safety issue, now I’m thinking bolt issue. I’m not familiar with the bolt but when it fails to fire I can sometimes get it to fire by by cycling the bolt a bit more briskly. Haven’t peeked inside yet, figured I’d seek some guidance first. I’ll start with a cleaning, of course, even though it seems reasonably clean.
Thanks in advance!
Is the bolt actually maintaining the firing pin in the cocked position when you close the handle? More often than not, the trigger is set too light or sear engagement to fine to allow the sear to hold the firing pin in cocked position when bolt is cycled. It can also be a dirty trigger that does not allow the sear to raise fully and catch the firing pin when cycling the bolt.
Is the firing pin traveling forward as you are closing the bolt, same scenario as holding the trigger as you close the bolt to remove the spring tension on the firing pin. If a trigger is adjusted too lightly it will affect sear engagement and allow the firing pin to come forward as the bolt is closed. An easy way to check this is to push the trigger forward from the backside as you are closing the bolt. If it will fire every time after you try this, you have your answer.
Looks like Steve and I posted at the same time with the same thoughts…….
Thank you, gentlemen! Trigger is very light and what I’m experiencing is consistent with the sear not engaging the firing pin if I’m understanding what you’re telling me. I’m hoping it’s just a bit of gunk or lint. I’ll look it over tonight, thanks for helping me understand how it’s supposed to work.
Mike, these Micromotion triggers have several levers and springs in them. Over the course of 60 years, they get oil and solvent down inside them. This congeals and makes the levers sluggish to move. The first thing I do when I get one is to remove the barrel action and clean the trigger thoroughly. I soak mine in carburetor cleaner, then flush with solvent. Another option is to spray it down with aerosol brake cleaner and then blow out with compressed air. Usually this alone will take care of the problem. As I mentioned previously previous owners try to get the pull weight down to a level they were never designed for. This is typically done by backing out the pull weight screw, or adjusting sear engagement to a point where the sear surfaces will not maintain the firing pin in cocked position. Most people don’t realize Winchester designed these triggers for a 3# pull weight which was required at sanctioned matches.
Thanks, Steve. Trigger is very crisp but it probably won’t hurt to blow a few decades of crud out of there.
I’m thinking the problem may be elsewhere, what do y’all think of the engagement surface on the firing pin? Hard to get a good pic of the edge of the sear but it looks fairly sharp to me. After I reassembled it the were no more failures of the firing pin to remain cocked so I quit for the night.
Erin Grivicich said
I can see by your last two photo’s that there is a large amount of dried crud around the trigger. As Steve mentioned, use choke or brake cleaner to soak it and hit it with some compressed air and I believe your troubles will be gone.
I think you’re right, Erin. Quite possible I disturbed enough of it to get it to work for now. Steve got me thinking about adjusting the sear engagement but will try to tidy things up a bit first.
Mike, I really see nothing wrong with the firing pin engagement surface. I think you are probably referring to the bottom corner of the firing pin where the sear makes contact with firing pin. That corner was hand honed at the factory to a .010″ radius. It should not be perfectly square. Again, I would pull it out of the stock, wash it down well with some cleaner, blow it out and see if that doesn’t take care of your problems. You can check the sear lever engagement while the stock is off and adjust it if necessary. Below is a picture of the engagement surfaces. I would try for a bit more that shown in this picture, maybe about .025″ to .030″. Very often the corners are damaged from too small of engagement and you have to increase the engagement to get them to cock. Just keep in mind, the pull weight spring has to be putting enough force on the lower lever to make it come up fully to engage the middle lever. All this said, none of the system will perform adequately if the trigger is dirty and gummed up. Always start with a good cleaning. Take a look at the schematic I sent you via private message.
Thanks again. You’re right, I was expecting to see a sharper corner there. Overall the gun is pretty clean but I haven’t had it out of the stock. The trigger feels very good, not gummy or gritty, but I’m betting you are right. I should get another chance to work on it in a few days.