The feed interrupter in my M39 Finn is not working properly and I was hoping some of you might have some ideas that I could try. I searched the forum but didn't find anything already posted. Here are the details:

 

The interrupter is not holding cartridges down in the magazine well. When the rims overlap incorrectly it prevents the bolt from stripping off the top round and pushing it into the chamber. It appears to me that the tab on the interrupter is not projecting out far enough past the mag wall and the cartridges are just sliding by it.

 

I have disassembled and removed the ejector spring/feed interrupter, cleaned it and the ejector, and reassembled. I have also put the ejector spring/feed interrupter in a vise and gently bent it a little to increase spring pressure. Upon assembly I made sure to insert the ejector spring/feed interrupter into the recess on the receiver before screwing it down.

 

So, have I missed anything? Any help would be appreciated. Thanks.

try turning the interuptor around. It is a common mistake to put it in backwards. you want the 90

try turning the interuptor around. It is a common mistake to put it in backwards. you want the 90

One last thing I can think of before replacing the assembly is to check the function without the stock on. With the stock off and the mag screwed onto the receiver try cycling. If it works without the stock check to see if the stock is relieved a little to allow full travel of the interuptor. I have had to dremel one in on a couple of mosins. As for a new interruptor try Sarco http://e-sarcoinc.com/search.aspx?find=mosin&page=2or http://www.buymilsurp.com or if all else fails, I get home from work in a week so just give me a shout then.

One last thing I can think of before replacing the assembly is to check the function without the stock on. With the stock off and the mag screwed onto the receiver try cycling. If it works without the stock check to see if the stock is relieved a little to allow full travel of the interuptor. I have had to dremel one in on a couple of mosins. As for a new interruptor try Sarco http://e-sarcoinc.com/search.aspx?find=mosin&page=2or http://www.buymilsurp.com or if all else fails, I get home from work in a week so just give me a shout then.

 

Sorry it's taken so long to get back to you but things got a little hectic for a while and I haven't had the time to work with the rifle. As soon as I get the chance I will try your suggestion and let you know what's what. Also, thanks for the parts sources. That will probably be the next step should I be unsuccessful.

 

Joe