M70 action sear pin

Warrenoliver

Well-Known Member
Joined
Mar 16, 2020
Messages
121
Location
McFarland, Wisconsin
Today, while doing load development with my Montana rifle company 280AI, I had a fail to fire. When I pulled the trigger, nothing happened and it felt like the safety was on. Turns out that the firing pin was falling immediately when closing the bolt. When I took off the stock, a small piece that I thought was a bolt fell out. Found out that it is the sear pin. When I replaced it, the trigger worked as usual and then malfunctioned again because the pin backed out. What holds this pin in place? Is it supposed to be an interference fit with the ridges on the head holding it in? Mine fits loosely and easily falls out. Any tips on how to keep it in place?

Thanks
Warren
 
You might try peening the pin with a hammer, that would enlarge it on the sides and might work. Best would be to get a new pin from Montana. If that does not work, you might try various drill bits to see if one fits tightly and cut it to fit. If you cannot find one that fits, take the next larger size, chuck it in an electric drill and reduce size with emery cloth till it fits
 
You might try peening the pin with a hammer, that would enlarge it on the sides and might work. Best would be to get a new pin from Montana. If that does not work, you might try various drill bits to see if one fits tightly and cut it to fit. If you cannot find one that fits, take the next larger size, chuck it in an electric drill and reduce size with emery cloth till it fits
0F67CC4E-761A-4488-A0F1-31ADFDAFB1C6.png
0F67CC4E-761A-4488-A0F1-31ADFDAFB1C6.png

This is what the pin looks like. I'm guessing that the ridges on the head provide an interference fit. On mine, they don't and the pin falls out easily.
No luck with Montana rifle company- they folded after I bought the rifle
 
Sir, sorry, did not know what type of pin was on the Montana action. I have model 70 sear pins. they measure .544 overall length, pin dia. is .159, pin length is .400, head dia. is .368. Mine are blued. You can get them from Mid West Gun 636-475-7300. If they will not fit, you might try peening the head of your pin, or put a drop of super glue on the head when installing it.
 
Sir, sorry, did not know what type of pin was on the Montana action. I have model 70 sear pins. they measure .544 overall length, pin dia. is .159, pin length is .400, head dia. is .368. Mine are blued. You can get them from Mid West Gun 636-475-7300. If they will not fit, you might try peening the head of your pin, or put a drop of super glue on the head when installing it.
Thanks for the info. I think I'll do that.

Warren
 
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