More barrel work to do:

[wash]

Once again I think I might have a line on a ~small lathe and will eventually use Techshop SJ and with an AR barrel project in the works, I picked up another project.

I bought a Mosin threaded UK59 machine-gun barrel for my Bannerman 30-06 New England Westinghouse Mosin Nagant.

The question of why I have an unsafe Bannerman Mosin is that a friend gave me a Finn M28-76 target stock and I didn't want to put a communist gun in it. The NEW receiver on the Bannerman was what I was after.

I initially wanted to get Lothar Walther to make me a wildcat 6.5*54r barrel for it but then I read about the "monster Mosin" which shot quarter sized groups at 200 yards with Russian surplus ammo and an $80 UK59 barrel.

So now I've got this huge 7lb. chunk of chrome lined machine gun barrel and a Mosin that I have to disassemble.

First step was to make a receiver wrench. It is a real pain in the backside to find a 1 3/16" wood drill bit at a local hardware store. I wound up with an "adjustable hole saw" to get the right size. None of the chisels said what kind of steel they used except for "hardened" so I got the cheapest one. The problem there is that it's a 1/2" chisel and I really should have bought 1/4 or 3/8". After a vise upgrade debacle, hacksaw removal of the rear sight base and a fair amount of chiseling, I had a wrench that fit.

I still haven't managed to get the old barrel out, the soft wood I used might be too soft. Luckily the carving was the easy part, it was everything else that caused problems.

Once I get the barrel off the problem becomes timing, headspace and the extractor groove. I will probably have to face the receiver, true up the locking lugs and maybe hit the bolt face too. After that I will need to profile the barrel but that is complicated by the fact that there are three cuts related to the UK59 carry handle. I want to remove the evidence, make it ~fit the stock and then flute it (because I've never seen a fluted Mosin...).

It's a fairly large project and I do not have experience with cutting such a long profile on such a narrow cylinder (the interrupted cut won't help).

In the end I will hopefully have a Mosin that shoots those quarter size groups at 200 yards.

[straykiller]

In the end I will hopefully have a Mosin that shoots those quarter size groups at 200 yards.

hurry up on this project so i can see some pics....

[wash]

I will have a few pics soon.

My 2x4 receiver wrench worked. I had cut a relief groove around about 270 degrees of the barrel (saving what was left of the NEW roll mark) and after a little heat, the wrench allowed the receiver to twist maybe 10 degrees and then the barrel broke loose. I was then left with a receiver that was stuck in a piece of 2x4 but it came loose after a bunch of wiggling back and forth.

After cleaning out the receiver threads, the UK59 barrel started in the threads just fine but it tightened up about 3/8" shy of the shoulder. I need to fool around with a marker to see what is stopping it.

I plant to take some photos this weekend and upload them on Monday maybe.

On the lathe front, I now own a slightly incomplete Jet 9x20 that seems to have a capacitor start issue but it was really cheap. It is probably not large enough for the profiling work the UK59 barrel needs but I will get some practice with lathe refurbishing and I might get something bigger later...

[wash]

I will be looking at some machine tools from Austria and Conneticut.

This could be very cool or a let down if the deal doesn't work out...

[wash]

I haven't been able to measure it yet but I think my barrel problem may be the thread pitch, I think the barrel threads might be 1.6 mm pitch instead of 16 TPI.

Those two are very close but not the same.

More details and photos to follow (probably Monday).

[wash]

The metric thread gauge I bought didn't have a 1.6 mm gauge so I had to use the 0.8 mm gauge (every other tooth) and to have some similarity in the test I compared it against the 32 TPI gauge.

The result was inconclusive. It is hard to tell the difference when you're using a tool wrong.

I found one metal chip down in the bottom of the receiver threads and I have been unable to dislodge it but I don't think the barrel is screwing down all the way to that thread. I think I'm going to have to grind a 3/8-16 tap to create a tool that can reach down there and be hard enough (and sharp enough) to cut out the chip in the threads.

On a positive note, it looks like if I thread it in all the way to the shoulder, the extractor groove will time up.

I haven't figured out if the headspace will work out with my bolt head but I hope so.

[wash]

The nice thing about rimmed cartridge headspace is that the two surfaces which determine headspace are easy to measure, unlike a rimless cartridge that you really need a headspace gauge to measure the shoulder with.

In my case, that let's me measure the barrel and bolt face to see approximately where the headspace will be when the barrel is torqued and timed.

I found a list of SAAMI headspace dimensions but it is from the Internet, I'll have to confirm it:

SAAMI "Go" gauge - rim thickness = 0.066"
SAAMI "No-Go - rim thickness = 0.071"
Military Field (Absolute MAX safe) = 0.074"

[jonmalibuss]

The nice thing about rimmed cartridge headspace is that the two surfaces which determine headspace are easy to measure, unlike a rimless cartridge that you really need a headspace gauge to measure the shoulder with.

In my case, that let's me measure the barrel and bolt face to see approximately where the headspace will be when the barrel is torqued and timed.

I found a list of SAAMI headspace dimensions but it is from the Internet, I'll have to confirm it:

SAAMI "Go" gauge - rim thickness = 0.066"
SAAMI "No-Go - rim thickness = 0.071"
Military Field (Absolute MAX safe) = 0.074"

Those numbers look correct for 7.62x54r. I made my own on a surface grinder and double checked them by using a live round that I pulled the bullet out of and dumped the powder, I added a couple pieces of scotch tape and it wouldn't lock. I have built a few 7.62x54r rifles with great success using these.