Cooey-Carcano 7.62x39 Project

[romayama]

7.62x39 Lee Enfield conversions have been done. A Lee Enfield barrel doesn't need much rechambering. The front end of the .303 chamber is just about a 7.62 chamber to start with. Set the barrel back just far enough to get rid of the excess .303 chamber. A Lee Enfield barrel can be breeched against the inner receiver collar if an external shoulder doesn't work.
In Australia, 7.62 and 5.56 conversions have been successful. A repeater is a bit complicated. Because of the smaller, rimless case head, a recessed bolt face might be required. Ejection will have to be dealt with. Conversions in the US have used single stack AK magazines. I have heard of Ruger Mini-30 magazines being adapted. Could a 7.62 AR type magazine be used?
If a single shot plinker is all that is desired, only barrel work is required.

Hi All, very interesting discussion, thank you!

I am gearing up for such conversion - L/E in 7.62x39 and dewat Mosin M44. Just debating whether to use the original barrels + reaming as discussed above, or to fit a chrome-lined barrel from the Norinco SKS (I have an undrilled, press-fit NOS barrel). I also found that neither AR or AK mags fit the magazine opening of the LE, without filing and compromising it. For that reason I bought stock Norinco single-stack bolt-action mags, and going to modify the LE shaft to accept those. CZ bolt action mags fit as well with room to spare.
Found a good video on the LE 223 conversion, just finding the ejection solution not being elegant, but will use it if nothin else works. For me it sounds easier to retrofit the bolt head with the plunger
https://www.youtube.com/watch?v=3p5_lex1VY8&list=WL&index=2

 

[tiriaq]

A plunger ejector can be fitted in a LE bolt head. There is not a whole lot of room, though.

 

[OkayShooter]

Hi All, very interesting discussion, thank you!

I am gearing up for such conversion - L/E in 7.62x39 and dewat Mosin M44. Just debating whether to use the original barrels + reaming as discussed above, or to fit a chrome-lined barrel from the Norinco SKS (I have an undrilled, press-fit NOS barrel). I also found that neither AR or AK mags fit the magazine opening of the LE, without filing and compromising it. For that reason I bought stock Norinco single-stack bolt-action mags, and going to modify the LE shaft to accept those. CZ bolt action mags fit as well with room to spare.
Found a good video on the LE 223 conversion, just finding the ejection solution not being elegant, but will use it if nothin else works. For me it sounds easier to retrofit the bolt head with the plunger
https://www.youtube.com/watch?v=3p5_lex1VY8&list=WL&index=2

Hi Roman, ejector plunger can be done. The issue is the not enough rebound to really flick the case out of the reciever. I found that I compressed too many springs, couldnt find one strong enough. So was alot of turn and dump.

Tiriaq tried it on the 9mm Lee conversion vs your spring loaded finger ejector. Make it the same size as a AR15 ejector. As you can get springs easier.

But between you and Richard, you'll figure it out, intrested in both your projects.

 

[romayama]

Hi Roman, ejector plunger can be done. The issue is the not enough rebound to really flick the case out of the reciever. I found that I compressed too many springs, couldnt find one strong enough. So was alot of turn and dump.

Tiriaq tried it on the 9mm Lee conversion vs your spring loaded finger ejector. Make it the same size as a AR15 ejector. As you can get springs easier.

But between you and ###### You'll figure it out, intrested in both your projects.

That is a very good info, thanks Gents! I think plunger ejectors may not be working great on the pistol calibers for their short casings that tend to tip too early. I have a spare L/E head and a R700 plunger and spring kit to experiment with, hoping to have better luck with rifle casings. If I screw it up, will just weld the hole and reuse the head for the pistol caliber conversion
I did a retractable spring loaded claw ejector before, just wonder if there's a simpler and more elegant way

 

[OkayShooter]

That is a very good info, thanks Gents! I think plunger ejectors may not be working great on the pistol calibers for their short casings that tend to tip too early. I have a spare L/E head and a R700 plunger and spring kit to experiment with, hoping to have better luck with rifle casings. If I screw it up, will just weld the hole and reuse the head for the pistol caliber conversion
I did a retractable spring loaded claw ejector before, just wonder if there's a simpler and more elegant way

It worked on 9mm dummies, but the lighter empty cases it would just drop into the reciever. I think you are right. It would tip up too soon and get pinned with the next round in the mag. Good thing about bolt heads, they're easially can be replaced without ruining the whole bolt.

 

[tiriaq]

I went through my rack of odds 'n' ends of barrels and found a R700 take-off sporter in .30-06. Measurements indicate that with the .30-06 chamber removed up to the shoulder, there is enough barrel diameter left to duplicate the C-C barrel shank and allow the 7.62x39 chamber to be cut.
Tried my reamer in the muzzle end of the barrel, and the reamer pilot just fits smoothly.
I'll cut a couple of inches off the chamber end, face it, then set it up with the bore on the tail center. Turn to .814", the cylindrical portion merging with the factory taper. Thread 20tpi for 1.05" until the barrel threads into the receiver bushing. Set up for chambering and ream until the appropriate gauge protrusion is obtained. Screw the barrel in and confirm headspace.

Also have a take-off Savage 340 barrel in .30-30. Going to scrub it out. If the bore is usable, this could be used instead of the R700 .30-06 barrel.
340 barre is .850-18, so redoing it .808-20 is quite practical.

 

[romayama]

Also have a take-off Savage 340 barrel in .30-30. Going to scrub it out. If the bore is usable, this could be used instead of the R700 .30-06 barrel.
340 barre is .850-18, so redoing it .808-20 is quite practical.

Given that 7.62x39 bullet is .310, I wonder if 308 bore may be too tight and pressure would be within norm. Lee Enfield barrels make a great candidate, as they are nominally .311. SKS even better.
BTW, greatnorthgunco currently has Carcano in 7.62x39 for sale, $450

 

[JJ-65]

I shoot pulled FMJ 123 gr. 310 bullets bullets in 30 cal barrels with neck turned brass, no problem.

 

[antiqueguy]

Are these safe in 6.5x54? I always hear that it shouldn’t be tried but they have survived this long.

 

[Tudenom]

Also have a take-off Savage 340 barrel in .30-30. Going to scrub it out. If the bore is usable, this could be used instead of the R700 .30-06 barrel.
340 barre is .850-18, so redoing it .808-20 is quite practical.

A 30-30 Lee Enfield would be an interesting rifle. Cheap and easy to find bullets and brass plus your handloads wouldn’t be that far behind 308 winchester.

I love the actions on the Lee Enfield but 303 Brit is quickly becoming an exotic cartridge that brings along a premium on bullets and brass.

 

[mbogo3]

Might as well go 30-40 Krag

 

[Dark Alley Dan]

Interesting stuff, Tiraq. Look forward to watching you work through this.

 

[Beater]

A 30-30 Lee Enfield would be an interesting rifle. Cheap and easy to find bullets and brass plus your handloads wouldn’t be that far behind 308 winchester.

I love the actions on the Lee Enfield but 303 Brit is quickly becoming an exotic cartridge that brings along a premium on bullets and brass.

i have a #4 i rebarreled to 220 swift fine shooter

 

[tiriaq]

Went through my barrel odds and ends.
I was planning on using a Remington 700 .30-06 barrel. But I found a Savage 110 .30-06. Might want a Remington barrel one day, less likely to need a 110. The Savage is a nice slender contour as well. Has the irons - Williams rear, Savage factory ramp and front sight. Also have a 788 .308 carbine barrel - but that isn't a very common take-off, so I passed on it.
Its breach diameter is just fine for the conversion, and the reamer pilot is an easy fit.

 

[tokguy]

Are these safe in 6.5x54? I always hear that it shouldn’t be tried but they have survived this long.

The 'old school wanna be gun plumbers' saw the set screw and thought it held the bbl in place...I don't think they knew about the threads LOL. It is safe...6.5 MS is likely close to 6.5 Carcano...interweb may prove me wrong of course.
I'm ripping home in the morning, can grab my CC with a M43 conversion if anyone has a query. If ain't that pretty...but it ain't that bad. Could use a removeable block...sometimes the cartridges go nose down and catawhumpuss. Shoots OK...aimpoint sights ain't that tight shooting I suspect.

 

[tiriaq]

With the hint of a Nock's Form showing, I assume that you threaded a No. 4 barrel to fit the Carcano receiver.

The M_S and M_C rounds are very similar. If a M-C is fired in a M-S chamber, the primer will be really flattened because of the excess headspace.

 

[tokguy]

With the hint of a Nock's Form showing, I assume that you threaded a No. 4 barrel to fit the Carcano receiver.

The M_S and M_C rounds are very similar. If a M-C is fired in a M-S chamber, the primer will be really flattened because of the excess headspace.

I bought it as is actually. But it is an No. 4 bbl I believe.

 

[tiriaq]

Did a bit more work today. Turned the 110 Savage barrel down and shortened it, to get rid of much of the .30-06 chamber. The reamer will need to go in about 3/4".
Next I'll cut the threads. If I can get the holes for the Savage rear sight top dead center without getting crazy, I'll trim back the barrel shank to get rid of the fixed sight.
Once the barrel is fitted, I'll ream the chamber and set the headspace. Won't take much cutting, given that the remains of the .30-06 chamber are there.

 

[tiriaq]

A brand new RWS 6.5x54 case projected .140" from the original barrel. I reamed the 7.62x39 chamber in the new barrel to give the same protrusion of the gauge. Relatively little reaming was necessary, because of the remains of the .30-06 chamber
Turned the barrel in until the bolt will not quite close on the No Go.
The conversion barrels have no shoulder or barrel nut. Fit on the threads is firm. The set screw on the bottom would preclude any rotation. I'm not going to bother with it - the 7.62 barrel is threaded for a snug fit. Its not going to unscrew on its own.
Incidentally, my internal action wrench works nicely in the Carcano receiver, in addition to Ruger, Remington, Winchester, Mauser receivers.
Could be test fired now.

 

[jamesharrison]

Can I ask why you did not simply remove the barrel stub & thread the barrel for the 1"x14 NS. of the Carcano receiver, almost the same as the Lee Enfield receiver threads?