M39 Magazine Feeding Problem

[Enfield47]

Sweet! Thanks for taking the time to find the elusive Mosin with the shims Brian! The pics really help me visualize the shims in those areas. That is a interesting rifle, if only it could talk.

The bolt will pull back fairly easily (just not as smooth as my Enfield's are), so that's a good thing. It only sticks a bit after firing or dry firing.

[81turbota]

Brian, rifles stamped USSR and not refurbished are most likely Spanish Civil war aid rifles. Cool history!

http://scwmosin.weebly.com/the-ldquomade-in-ussrurrsrdquo-stamp.html

Enfield47- I think the shims will do the trick!

[Flyin Brian]

Brian, rifles stamped USSR and not refurbished are most likely Spanish Civil war aid rifles. Cool history!

http://scwmosin.weebly.com/the-ldquomade-in-ussrurrsrdquo-stamp.html

Enfield47- I think the shims will do the trick!

It's not stamped USSR... I was just saying it did not stay there in Soviet hands or it would not be a dragoon anymore

It has none of the usual SCW features, and the stock has never been sanded.

[81turbota]

Ah, misread your post. Cool rifle none the less, it evaded the Soviet 91/30 puppy mill.

[Vlad 11]

Hmm looking into it again, i don't think its primarily a shimming issue.

I glanced at a number of rifles and it looks to me like you have a interrupter spring with a wider than usual hold down tab. And this may be coupled with a magazine that has a narrower than usual tab inlet or otherwise they dont fit well together. So when the bolt actuates the on the ejector and retracts the hold down tab, the tab gets hung up on the magazine. The remaining cartridges in the magazine will then have nothing holding them down and they want to spring up into the receiver creating a logjam.

If this is the case, simple fix. As 6mm said just a little filing to gain ample clearance for the tab.

Again i would suggest to assemble the action out of the stock and function test cycle (please with dummy rounds or snap caps!) This will show exactly what is happening

Here is a (very slick actioned) Type 53 for reference on proper clearance





That's my theory anyway

[Enfield47]

Wow, my interrupter has nowhere near that amount of clearance. I'll see about stoning a little off the side and bottom where it is hitting. Do I take off just enough for better clearance or all the back to where the interrupter has hit the magazine?

I also have the shims cut out of a plastic card to use as well. Even if they don't hold up for more than a couple of range trips, I will know the thickness to replace them with steel versions.

I'll make a couple of dummy rounds to test the action. This is where reloading helps too.

[81turbota]

I have a "master set" of pre stamped shims, enough for 5 rifles. If you need some, I would be more than happy to bring them to the next shoot. They are easy enough to swap out.

[Enfield47]

I have a "master set" of pre stamped shims, enough for 5 rifles. If you need some, I would be more than happy to bring them to the next shoot. They are easy enough to swap out.

Thanks, that would be awesome! Just let me know how much and I'll reimburse you.

[81turbota]

Thanks, that would be awesome! Just let me know how much and I'll reimburse you.

Let me put a few rounds through your nice M39 and all is good The shims came out to around $1 ea, so its no heart break.

[Vlad 11]

Wow, my interrupter has nowhere near that amount of clearance. I'll see about stoning a little off the side and bottom where it is hitting. Do I take off just enough for better clearance or all the back to where the interrupter has hit the magazine?

Well completely test it first to determine the exact problem before grinding anything. I'm thinking its a side to side clearance issue of the spring tab. The bottom of the tab functions to hold down the next cartridge in the magazine so probably not good to shorten it.

I'm a bit baffled how the tab could even touch the bottom of that slot. None of the ones I looked at even came close

[Enfield47]

I measured the width of the interrupter tab and the notch out in the magazine. The interrupter tab is .251 inches and the notch in the magazine is .264 inches - my clearance is only .013 inches and almost all of it is on the front side of the notch (where it isn't getting caught underneath). I'm thinking I will need to relieve a little more on the back side of the notch to keep it from getting caught underneath that edge.

I'm scratching my head over how the interrupter tab could hit the bottom of the notch in the magazine too. There is ample clearance, so perhaps the ding in that spot happened at some other time in the rifle's history.

I'm going to have to order a set of stones from Brownells, I thought I had one that I could use but it's just a round ceramic stick and I need one with a flat surface. What do you think about this set?

[knucklehead0202]

I'd file rather than stone, Brian, it'll take forever. That's a good deal for a stone set though, and Brownell's is always good stuff. Stones are for finer, more delicate work, and this is a Mosin Nagant, it may reject them, lol. A rock and a stick may be more appropriate tools.

All kidding aside, I picked up a set of small files at Harbor Freight that includes several little files in all shapes. I've used them a ton on various gun-related projects and I think the set was like 5 bucks. Take a run down there, I guarantee you'll buy WAY more crap than you came for, but still only spend 40 dollars.

[Vlad 11]

I measured the width of the interrupter tab and the notch out in the magazine. The interrupter tab is .251 inches and the notch in the magazine is .264 inches

Checked several and got
.338
.341
.339
.343. on the mag notch

The spring tabs are tapered but they are @ .225 - .226 where they clear the mag.

A replacement magbody and spring will run about $20, something to consider before buying tools

if the clearance is indeed the problem the math says you're 1/8 inch out of spec on the notch. doesn't sound like much but that's a lot of fileing in that tight space

[OniKoroshi]

Best $8 you'll spend in a while.

http://www.harborfreight.com/10-piece-diamond-grit-needle-file-set-69876.html

[Enfield47]

Thanks guys, that Harbor Freight file set looks good and the price is right too. I'll have to take a trip over there one of these weekends.

Vlad, does it matter on the magazine type if I replace it, or are they all basically the same? Should I try to find a Finn magazine? My receiver is a Tula hex 1896, if that matters.