HELP Mast Molder Trouble....

[Krom 36]

I'm having a very frustrating time trying to get my new master molder mags to feed correctly on my next to last rnd. I have two 7.62x39 saigas the mm mags work fine in one and not in the other, both have bullet guides installed.

 

The full symptom is I load 3rnds rack it, fire and the weapon ejects the spent casing plus an unused rnd, leaving no rnd in the chamber.

 

I'm totally confused, tried taking the lip down some on the front part of the mag, no change and shaving a little some plastic off the back of the inside of the mag so the round can sit further back in the mag, reduced the number of failures but does not eliminate the symptom. The problem is I should not have to modify other parts of the mag other than the catch to make it fit or work correctly.

 

Then I took both bolts out of each weapon and compared the bottom parts that contact the rounds. I compared them and the one with the failures was triangle shaped on the bottom and the one that worked sloped down and then was flat on the bottom. So I did something pretty stupid, I filed the bottom of the effected bolt flat, and I think I filed it down too much. The filed bolt still works with the factory mags but is really close to being too short and I did get it to miss the back a round using the master molders and stove pipe.

 

So I'm going to weld some additional thickness back onto the bottom of the filed bolt and return it to the its same previous height. Problem is that I still don't know what the f*ck is wrong with the mm mags feeding problems. It's like the problem round leaps out of the weapon, but only when it is fired (manually it feeds great).

 

PLEASE HELP ME!!! I'm lost...

[sicktooth 8]

i hear ya brother...im having other problems...must be a bad day for Saigas or something...

[acercanto 6]

Okay, I have no experience with Master Molder mags or even the x39 Saiga, so take this as you will. My hunch, from what you said is that one of two things is happening.

1) The round is jumping past the feed lips because the spring force is enough to bend them when the gun cycles. Kinda hard to explain, but it boils down to the feed lips being too flexible, or shaped wrong.

2) The bold is dragging on the top round in the mag and popping it to the center (which lets it fly out) when the bolt heads rearward. Maybe catching on the extractor lip.

 

Remember this is just some random hunches based on not much knowledge at all. But maybe it'll help, so enjoy!

 

Acer

[Krom 36]

Ok, I think I may have found the problem... But I will have to test it to see. I wielded some addtional metal onto the bottom of the bolt to fix my previous f*ckup of grinding it down too far. (veiw attachment) and I had a brain fart, maybe now that I've wielded new lump of steel onto the bottom of the bolt I reshaped it to more of a downward V leading up the part of the bolt that contacts the rnd (the surface that contacts the rnds to move them into the chamber is the same shape, this way when the bolt slides over the rounds as it is comming back it will push the rnds outward and down instead of just down (possibly causing the rnd to jump into the center and out).

 

I'll keep you posted on my progress, hopefully this will fix my issue.

 

Also I did not take the bolt assembly down when I wielded the addtional steel onto the bolt, so should I be worried about the heat from the wield fatiging the firging pin or the ejector spring?

[Krom 36]

Good NEWS!!! I finally figured out what the problem was.. and it had nothing to do with the bolt as far as I can tell. I continued to reshape the lower portion of the bolt to what I thing is a more optimal shape (polished+v shape leading up to the same front shape) so the above picture is allitle incorrect.

 

Anyways the problem was the inward slant of the top portion of the magazine as pictured in my attachment. I'm thinking that when the bolt would rapidly press the rnds down when the weapon was cycled it would push the rounds slightly outboard, and the narrow front portion of where the round sits is too narrow to accommodate this motion resulting in the back of the round kicking inward and thus unseating the rnd and causing it to eject.

 

So if anyone else experiences this you can fix the problem by grinding (dremal) the part of the mag that is at the tip of my finger. I when ahead and kinda hollowed out the inside of where the round sits too to give it a steeper inward grip on the rnd.

 

I fire 40+ continuous shots as the 2nd to last rnd (load 3rnds, rack it, fire, pull mag and place another rnd into the top of the mag) and NO MALFUNCTIONS!!

 

Thanks and I hope this info will help some one else too, cause I'm freakin stoked....