Customer’s gun is misfiring with light strikes. And no wonder. No positive protrusion that I can see and perhaps .030 absolute. Rimfire case cut seems nominally to spec. My first instinct is the remove some material and re polish at the back of the bolt…as opposed to stretching the pin, since that is so highly polished and fitted along its top edge.
Before I do this. I’d like to check first. I worry that afterwards function checks may make me wish I had that material back. So this is just a sanity test…before I proceed.
I will probably check the following and weigh my options.
After re-tipping a few firing pin, I found the technique very useful for repairing worn parts. I see as a dentist putting a crown over a bad tooth. When done correctly, it can last. -TL
How much is it going to cost me if I screw it up?
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This is a question I really need to learn how to ask. 🙂
I’m a lot more apt to choose replacement or modification of a firing pin than a bolt, since the bolts are harder to work on and affect more things. Plus they’re more expensive when I screw up. But, I guess it still depends on observing all the potential problems and solutions before I decide what to do. Jeff
Follow-up on question
After sleeping on it…I’m going to work on the absolute protrusion by focusing on the pin first. I can stretch and remove a tiny bit from its limiting surface…before I work on the positive protrusion. This is a pretty heavy firing pin. I think it’s just a bit short from the factory…even though owner said that this problem has developed over time. (He’s second owner and seemed a bit fuzzy in this point and I think that maybe the gun has always skipped an occasional beat)
BTW…is it relevant that he actually shoots shorts. On test firing, his old Winchester shorts misfire every second, third or fourth shot. When testing with Federal long rifles. Every round misfired. All leave a light strike impression.
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That might make a difference. I would check rim thickness of the shorts compared to the long rifle rounds. They actually make a gauge to check rim thickness of rimfire rounds. It’s supposed to help in accuracy. You can make one fairly easily. Check headspace too.
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Take the bolt out and see how much positive protrusion you have. If it isn’t enough take material off the back of the bolt so the hammer can push the firing pin further forward. You would have to take off alot to ruin the bolt. Ken
Reply
Thanks. That did the trick. Made positive protrusion around 0.025 and bumped absolute protrusion a few thousandths. All good now. Except, I’m getting occasional feed failure with empty and feeding round both ejecting simultaneously. I need to investigate that.
