Monster Mosin Wanna be

[matt6669 71]

Because I'm such a fan boy after shooting Eric's monster mosin I had to have one for myself.

 

First thing I did was acquire the barrel from TG International. Then I put the barrel on a lathe and took off all the extra material that was left from when it was an actual machine gun barrel. I'm now in the process of doing a 400 grit sandpaper sand on it, then I'll switch over to a 600 grit wet sand on it.

 

I'm still in the process of deciding whether I want to blue this gun or give it a camo paint job I can't decide.

 

I borrowed an action wrench from Eric and with the help of the vise on a bridgeport I was able to break the barrel free in less than 2 minutes without damaging the barrel at all. (the used mosin barrel will be getting frankensteined by Eric so stay tuned for that build sheet.)

 

I will post pictures tonight of how everything sits for far.

 

Next thing on my list of things to do is drill and tap the receiver for the scope mount, get the receiver on the bridgeport to shave the front of the receiver so I can achiever proper timing, and then lap the lugs in order to get my proper headspacing. Then it's to start building the stock for the gun.

 

Tons left to do, but I'll be doing a little bit here and there and posting pictures as I go.

 

M

[JonF 79]

I too have done a little bit with my barrel over the winter. First i turned down the barrel on a lathe a little bit to remove some of the hump. May still remove a bit more to get a smoother profile but that small diameter step where it butts up against the receiver will have to stay, i'm not turning that much material off.

 

I've also separated my stock barrel from my receiver and test fitted the TGI barrel and the timing seems ok. If i tighten it a reasonable amount without any excessive cheater bar induces torque like the stock barrel, the alignment is OK with respect to the extractor cut. If i wanted to crank it down a few hundred foot pounds, i'd have to take some off the barrel or receiver but then i could run into headspace issues.

 

I've checked the headspace with some go/no-go gauges and its fine as it is. Be extremely wary of that if you think you'll remove material. It seems that TGI makes the extractor cut much more generous (ie. longer arc) than the stock barel to compensate for such alignment variances.

 

The only barrel adjustment i had to do so far was do some minor clearancing on the extractor cut channel as it was not milled very evenly at the extreme ends. Cycling the bolt with the barrel installed showed that the tip of the extractor was dragging and hanging up on inside the relief channel so i had to massage that slightly.

 

Have you thought about any muzzle treatment? I'll be eliminating that ugly "crown" they drilled in and putting a brake on it.

 

Maybe a teflon or melonite finish to the metal parts once everything is done.

[matt6669 71]

UGHHH so jealous

 

My timing isn't even close. I need to shave .005 of an inch off the front of the receiver to get my timing where it needs to be. But with the barrel screwed all the way in, I can't even chamber a round. So that means I got some serious work to do. My go/no go gauges will be here Wednesday that I ordered for the M28/76 to figure out WTF is going on with that gun so this gun will be getting those gauges to see exactly how far off I really am.

 

I think I might be going to a JP Tank Brake. I'm awaiting a reply from E Arthur Brown Company they sell the brake and will professionally install it for like 170 bucks. The reviews for the company are outstanding but from their website they only install on encore barrels. So I emailed them to find out if they will do it on this barrel so I await their reply.

 

Chances are, I'm going to shoot the gun first to get a baseline accuracy to see where the gun is before I do any muzzle brake treatments. Reason being is from what I've read is that most of the time a muzzle brake reduces accuracy rather than improve it so having a baseline before more work done is always a plus.

 

I'm really excited I can't wait to finish this project. I too am hoping to redo the whole crown situation because I'm convinced that they didn't center the crown when they redid the barrel. When my barrel is on a live center in a lathe, the very very end of the barrel has a little wobble to it. I'm really home its just not a centered crown cut and it'll be an easy fix if i sent it to E arthur and hopefully its not the barrel.

 

Ahh the joys of tinkering

[JonF 79]

When you install the TG barrel, does the bolt operate freely at least?

[matt6669 71]

to tell you the truth I don't remember. But if it does, thats the same problem I'm having with my m28/76. The bolt operates freely with nothing in it, you put a loaded cartridge into the chamber and try to close the bolt and its a no go.

 

I can't wait to get my gauges so I have a clearer picture of what's going on.

[JonF 79]

hmm... could be some hardened cosmo in the bolt recesses on your Finn. I once had a 91/30 that did the same and repeated cleanings with some angled brushes helped toe finally dig the crud out. In fact, after i pulled the barrel off this donor mosin, there was still cosmo in the bolt recesses and i had been using this one for years!

[matt6669 71]

well I just got home. Screwed the barrel on hand tight and the bolt won't even close without a round in the chamber. I thought I had tried this and had come to this conclusion already. So it seems I would be better off trying to take some material off the actual face of the barrel rather than taking material off from the receiver. My guns are never easy GAHH

 

and the M28/76 has gotten a serious hot water bath and scrubbing so I'm not sure there's cosmo in there anymore. I really thing I have a too tight headspace issue which I'm hoping is the case b/c it can be an easy fix and that means the gun is super duper cherry

[matt6669 71]

ok making progress. I decided since my timing is slight off I should remove the extractor and then try and close the bolt. SUCCESS!!!! Now put a round in the chamber and close the bolt. SUCCESS!!

 

So I currently don't have headspace issues. I'm going to wait for my gauges to come in to see how close I am to the minimum saami specs and then decide how I want to deal with my timing issue. From my measurements I should only have to take off about .005 of an inch to get me where I want to be so hopefully I can use my friends bridgeport and get that taken care of. I'm almost tempted to use a file but I'm trying hard to avoid the temptation.

[JonF 79]

remember, you only need 90* of the usable extractor cut channel for it to ride in. They cut it a lot longer than that to compensate so there could be enough depending on how tight you make it.

[matt6669 71]

ok good to know, so hopefully I won't have to go too far I hope.

 

Can't wait to get my gauges, they are taking forever

[JonF 79]

Off hand, do you know the thread pitch and the amount of axial advance per rotation?

[matt6669 71]

huge negative.

 

When I go to do it, it'll be a thousandth at a time until its where i want it

[junkmanted 54]

what still no pictures ????

 

When you get tired of that M28/76 let me know

[Old School 611]

Off hand, do you know the thread pitch and the amount of axial advance per rotation?

 

 

Matt- you should take the time to figure this out. I have metric pitch guages and it would make your life easier because it is less hit and miss. Stop by we'll do the calc and convert it to inches.

[matt6669 71]

NVAR TED!!!

 

I will figure out this stupid M28/76 if it's the last freaking thing I do. I think I already know my plan of attack I am just awaiting my go/no go gauges to come in the mail to have a better picture of how things are.

 

And pictures maybe tonight, I got busy working on stuff last night and lost track of time.

[junkmanted 54]

if your gauges dont come soon let me know Keith has mine I can pick them up

[matt6669 71]

they will be here tomorrow according to ups so I should be good to go I hope keeping my fingers crossed but thanks for the offer teddy. BTW your 308 ammo will be here tomorrow as well lol

[JonF 79]

Yo Matty, get your gauges yet?

 

I've got my comp in-hand (Badger Ordinance Thruster) and just need my buddy to get back in town so we can hit the lathe again and fit this up.

[matt6669 71]

yes yes got my gauges in. I am going to take material off from the front of the receiver which will probably amount to .04ish of an inch. Obviously we will take it off in very little amounts until I get that extractor slot to be at the 3 o'clock position and then I should be good. By doing this it will also allow me to tighten up my headspace and then I can really lap the lugs on the bolt so I can get hopefully close to 80% coverage.

 

of course all of this has to wait like two weeks until I get back from my cruise boo

 

let me know how that brake works for you, I'm keeping my options open as far as brakes.

[JonF 79]

The general consensus of the Thruster seems to be good for a 308 class rifle. The king of brakes would be the JP Tank brake but its quite a bit of money. The Badger Ord is nearly half the cost of the JP and yet still offers great performance. Of course, the sheer heft of the barrel alone, the recoil will be noticibly reduced and with the addition of this brake, it should be rather humorous with the amount of noise and flash the mosin will generate with a shorter barrel.

[matt6669 71]

heh yeah I'm going with the JP Tank Break for my build. E. Arthur Brown Company will sell you and professionally install the JP Tank Break for 169 dollars. At that price point I won't even attempt to try and install the brake by myself it's not worth it. But I'm not going to send it to them until I get to shoot the gun and get a baseline for how the gun performs without the brake. From what I've read most times a brake will reduce accuracy rather than improve it so we shall see. I definitely want a baseline before I do anything tho.

 

ps what scope mount did you end up using?

 

M

[JonF 79]

Between the heavy barrel and the JP brake, you guns' gonna feel like an extremely noisy .22! lol

 

I'll eventually pick up a drill-n-tap hex mount from rock solid. I already have a bent bolt from the boltman from my last experiment. I think i'm then going to get the metal melonited. The roughness of the mosin components doesn't seem fitting for a deep blue job.

[matt6669 71]

yeah I was going to do a deep blue but my barrel has some imperfections that I can't get rid of without taking away a decent more material so I think I may just paint it. Not sure how I am going to paint it though. I may just copy the marine sniper paint job if I can pull it off.

 

I highly suggest the rocksolid mount the thing is freaking serious. It's what I'm going to use on my gun which I am also going to bed the mount to the receiver with some jb weld as well.

 

M