Blew out my m-305 extractor

[valmet762]

I was enjoying a great day at the range today... i was just squeezing the trigger on the 300 yd gong when I hear the dreaded CLICK..

i wait a bit, open the bolt and and i dont see a dent on the primer.. so i close it up and again.. CLICK

then i look realy close and notice my extractor had popped out on the bench with my last shot..

i actually didn't even lose any parts.. I took it home and fixed it with the help of a clamp and a lot of cursing...

it seems ok now..

i inspected the fired brass and it looks good.. what could cause this?

 

[Hungry]

Who knows? I remember losing my extractor and resulting bolt parts in the grass during a 300yard deliberate match. I had to drop several points by forfeiting the remaining rounds, then I scrambled in my rucksack for my 'Oh Shzt' kit... I've got an entire set of spare bolt parts in there. IIRC , that happened back in 1993, we even had free 7.62mm IVI ammo allotment through the ORA back in those day!

I got the bolt together with a spare set of hands and returned in time for the 300 yard snap match. Mons Range west side, back then there wasn't a huge berm to the 400yard mound.

My best guess is that when a round chambered, by some fluke, the rim of the cartridge lifted the extractor upwards as it was pushed forward and then up into the chamber, remember the rim / base of the cartridge rotates upwards. It was during this motion the extractor was lifted out of place. What a fluke!

Hope this helps!
Barney

 

[valmet762]

I'm sure it was a fluke.. i've got at least 2000 rounds thru this rifle without any problems...

I got the bolt back together and it seems to be working fine..

i chambered an empty case a few times and when i pulled the bolt back it extracted without any problems.. i did this about 10 times and seems ok.. tomorrow I might take another trip to the range and test it with some live rounds..

one thing i noticed, (and i cant remember if it was like this originally) is that when i press the extractor with a screw driver, there's very little movement (almost none) to the side.. almost like the spring is compressed to the max..

is this normal or did i put it back together incorrectly? although, like I said, it does extract properly manually..

thanks for your feedback Hungry, and I guess i'll be looking forward to your next clinic in southern ontario..

 

[purple]

There are several possibilities to consider;
1.ext plunger spring is weak allowing plunger to slip out of extractor detent
2.ext plunger is deformed/worn allowing it to slip/bounce out of ext detent
3.ext detent is worn enough to allow the ext plunger to disengagefrom it
4.ext stem extends beyond flush with bottom of bolt which would allow a round in the rt side of mag to come into contact and lift it upwards
5.bolt body oversize in ext/ext stem mounting area

 

[valmet762]

went to the range today and blew off 30 rounds and extractor seems to be working fine...

i checked the bolt after every 5 rounds to see if there was any movement in the extractor, or if anything looked out of place... but everything looked good..

time will tell i guess.. but i think it's going to be fine.

thanks for the input Hungry, and Purple, I'll keep an eye out for the stuff you listed.