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About eight years ago I picked up a couple of USGI kits from Coles. Finally getting around to building them and dug out the boxes. Included was this barrel in .30-06 with no markings of any kind and interesting intermittent cuts at the muzzle end. Obviously an attempt to cut down drag on the booster and possibly give carbon build-up a place to go during long strings of fire.

Thought you guys would be interested in pix.

IMG_0550.JPG IMG_0552.JPG
 

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Hmmm....maybe someone thought it would be a good place to stuff grease to lubricate and keep carbon from sticking??
 

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Thats some bad pitting on the bearing surface. I would guess a post ww2 foreign country production. Maybe your side left side plate might have some clues. You have a late production Saginaw topcover there. It looks like an in the white lockframe as well.

What parts makers are present, style trunnion, marks on trunnion top, LSP, Etc. Sometimes the European nations left stanpings from overhauls etc that might help us figure out who made the barrel.

BTW- I WOULD NOT use that barrel with the pitting like that. If the chamber and bore are good consider it a candidate for turning down to use as a 1917 barrel.
 

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Someone...BeltFredFrog I think....wrote up a post about accurizing an A4. Quite informative.

There were groves cut for "O" rings on the Trunion end a zerk fitting or 2 installed as well. iirc?

I don't recall what was done at the muzzle end?...perhaps He will refresh our memories.
 

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The bearing is supported by the booster and reciprocates back and forth. I would think that the pitting would cause damage to inside of booster acting like a file. If it was only a couple spots no big deal but the nature and prevalence you do not appear to have any good bearing service left. I do not think it worth taking a chance. You may be able to polish a lot of it out but you will be increasing the blowby (read blast out the shroud in your face) and possibly reducing the amount of energy captured by the booster to operate the gun. It may not though, you would need to experiment with it to see. Just wear your eye protection and ears when you do
 

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I've seen the inside of some really caked up and pitted boosters too - but the guns still ran OK.....Just not to accurate..... I've seen cut-downs that had NO booster ring incorporated on to the muzzle end. Same scenario - ran OK, but accuracy stunk. These were blasting guns tho, so no one cared really.

Still - there comes a point when it's time to rotate in some new parts. This might be one to keep in mind for the near future......
 

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Discussion Starter #8
It's definitely a blaster barrel. There is a hint of rifling, but only a hint. Have several NOS so don't plan on using it, just thought it was interesting.

Here is a rundown on parts markings:
Bottom plate - S.G. and drawing number
Bolt and extractor - S.G. and drawing numbers
Top plate - ordinance bomb and "P"
Accelerator - S.G. and drawing number
Lock Frame - ordinance bomb
Top cover - there is a mark in the recess below the hinge lug that looks sort of like a lower case "r". Izzy?

That's it. No marks anywhere else.
 

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It doesnt appear to be izzy but flip it and see if she has an izzy modified feed area. Try to post a pic of the r. It could just be a production mark.
 

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. . . and the mystery deepens. I did a chamber check and both bore and chamber are cut for 8mm Mauser. Verrry interesting!!
 

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Crud, I cannot remember which country did it but some eastern European nation did run their bmgs in 8mm. Do you have the feed guide with it? Hopefully whenbthe knob creek gang settle in and start poking their noses in, if they are not having cocktails in the hotel...

Thats still a GI cover, been refinished though.
 

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Crud, I cannot remember which country did it but some eastern European nation did run their bmgs in 8mm. Do you have the feed guide with it? Hopefully whenbthe knob creek gang settle in and start poking their noses in, if they are not having cocktails in the hotel...

Thats still a GI cover, been refinished though.
I believe Yugoslavia converted their A4's to 8mm. They had a bunch of M18 and M36 TD's that we gave them. Also, years ago, a bunch of Yugo 8mm ammo was imported that was on browning links and packed in the M19 style ammo cans.
 

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The bearing is supported by the booster and reciprocates back and forth. I would think that the pitting would cause damage to inside of booster acting like a file. If it was only a couple spots no big deal but the nature and prevalence you do not appear to have any good bearing service left. I do not think it worth taking a chance.
Ah, I understand. Thanks for both explaining it and guiding the OP further.

I was just talking to a local 1919 guru who is a machinist and we got into a long talk about accurizing the 1919. He also spoke about trying O-rings before moving on to another solution more robust. My experience comes from the rifle world where you don't want anything touching the barrel (bedding the action of a bolt rifle or "free floating" barrels on other platforms. Wouldn't you want the barrel to NOT touch the booster because of its negative impact on accuracy?
 

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.... You may be able to polish a lot of it out but you will be increasing the blowby (read blast out the shroud in your face) and possibly reducing the amount of energy captured by the booster to operate the gun. It may not though, you would need to experiment with it to see. Just wear your eye protection and ears when you do
The purpose of the grooves may be to decrease blowby. They may function like a Labyrinth seal, with each channel decreasing the velocity of the escaping gasses, and thus increasing back pressure. Just a thought.

....I was just talking to a local 1919 guru who is a machinist and we got into a long talk about accurizing the 1919. He also spoke about trying O-rings before moving on to another solution more robust. My experience comes from the rifle world where you don't want anything touching the barrel (bedding the action of a bolt rifle or "free floating" barrels on other platforms. Wouldn't you want the barrel to NOT touch the booster because of its negative impact on accuracy?
There is a tremendous amount of slop between the Barrel and the Trunnion and Booster. This is probably to allow for thermal expansion when things heat up. As a result, the barrel just lays in the Booster when at rest, and flops around quite a bit when fired. If you push on the bottom of the Barrel through one of the holes in the Barrel shroud, you will actually feel it move. I don't know what the design clearance is, but I wouldn't be surprised by something like 0.015 - 0.030. A quick look at the I.D. of the Booster and O.D. of the Barrel specified in the ordnance drawings would tell us.

There was a discussion a while back concerning the use of heat resistant (red) O-rings and a liberal amount of grease to make a 1919a4 more accurate, with one board member reporting success. The effect is to precisely locate the Barrel in the Booster, and thus eliminate the slop. I looked briefly for the post but can't find it. MSG
 

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I figured the grooves were to capture the gasses and assist. The blowby comment came from speculating on the potential decrease in diameter of barrel with what might have to be removed to get a smooth bearing surface again. Its an interesting peice
 

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Mr.Maim,
The O rings are not rubber but Viton at a minimum ,the best is Rulon 945 it has the highest heat resistance and is used in oil less compressor piston rings .
 

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About eight years ago I picked up a couple of USGI kits from Coles. Finally getting around to building them and dug out the boxes. Included was this barrel in .30-06 with no markings of any kind and interesting intermittent cuts at the muzzle end. Obviously an attempt to cut down drag on the booster and possibly give carbon build-up a place to go during long strings of fire.

Thought you guys would be interested in pix.

View attachment 14215 View attachment 14216
Are you sure that you did not purchase that kit from APEX or MGS?
Way back around 2004 we had a batch of M1919A4's that Century imported from Yugoslavia.
As I was handling the kits I discovered that some were 30-06 and others had the barrels that look like MG34's at the muzzle end and were chambered in 8MM.
The 8MM guns had the proper cartridge stops, etc for the 8MM round.
I kept one kit and sent it to John McQuire for building into a semi.
One key give away on the Yugo M1919 and M2's was the bluing process that left some parts very red.

I took some pictures of the barrel & markings and also of the 8MM parts used on the feed tray.

Richard

Yugo muzzle.JPG

Yugo Military inspector smokeless powder proof mark.JPG

DSC01670.JPG

DSC01671.JPG

DSC01672.JPG
 

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...
Way back around 2004 we had a batch of M1919A4's that Century imported from Yugoslavia.
...
The 8MM guns had the proper cartridge stops, etc for the 8MM round.
...
I took some pictures of the barrel & markings and also of the 8MM parts used on the feed tray.

Richard


View attachment 14350

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That's an 8mm configuration? Interesting. Totally different looking than the pictures of my (still in ATF jail) 1919, chambered in 8mm. I'll start a new thread rather than derail this one.
 
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