Reproduction of "De Lisle" Carbine

[tiriaq]

The barrel has to be fitted to the altered receiver. Once the receiver is bored out, the barrel has to be fitted. Every Delisle was essentially a one-off. I'm not sure a finished, ready to spin in barrel would help.
One way to bore out the receiver is to do it on a lathe. A mandrel is inserted in the rear of the receiver and held in the chuck. A bushing is threaded into the receiver ring, which is supported by the lathe's steady rest. The receiver axis is aligned with the lathe's axis. A boring bar is then used to bore out the receiver (and the bushing, depending on the size of the starting hole). Low rpms required because of the eccentric receiver and interrupted cut. I suppose a piloted annular cutter could be used if available.
When the bolt is shortened, the bolt head has to be timed. Once it is timed, the actual finished length from the receiver face to the bolt head is fixed. The receiver counterbore, barrel and bolt have to be in harmony. Just a thought - might be an idea to do the bolt first, before boring the receiver and finalizing the barrel.
There is a US site - .weaponsguild.com. Production of a number of accurate Delisle reproductions has been documented there, including legal fully functional suppressed versions in Europe and the US.

[Brian B]

The barrel has to be fitted to the altered receiver. Once the receiver is bored out, the barrel has to be fitted. Every Delisle was essentially a one-off. I'm not sure a finished, ready to spin in barrel would help.
One way to bore out the receiver is to do it on a lathe. A mandrel is inserted in the rear of the receiver and held in the chuck. A bushing is threaded into the receiver ring, which is supported by the lathe's steady rest. The receiver axis is aligned with the lathe's axis. A boring bar is then used to bore out the receiver (and the bushing, depending on the size of the starting hole). Low rpms required because of the eccentric receiver and interrupted cut. I suppose a piloted annular cutter could be used if available.
When the bolt is shortened, the bolt head has to be timed. Once it is timed, the actual finished length from the receiver face to the bolt head is fixed. The receiver counterbore, barrel and bolt have to be in harmony. Just a thought - might be an idea to do the bolt first, before boring the receiver and finalizing the barrel.
There is a US site - .weaponsguild.com. Production of a number of accurate Delisle reproductions has been documented there, including legal fully functional suppressed versions in Europe and the US.

tiriaq,

Thanks for the additional information. The process is quite involved if done correctly it appears. I've looked through weapons guild a few years ago and there is some excellent information on may firearms with some very talented builders.

Perhaps one day I will attempt to make a non suppressed version as they are an interesting variation of the Enfield line.

Thanks,

Brian B

[browningautorifle]

Once the receiver is bored out, the barrel has to be fitted

The receiver doesn't need to be bored out, the barrel shank is threaded forward of normal. The barrel can be done two ways, normal shank with the magazine sitting forward to meet the breech and short throw bolt with the breech sitting back like the original. Then the magazine housing still has to be altered to take the mag. The short throw bolt is more complicated as you need to cut the bolt and tap it to take the head. The bolt head doesn't need to fit inside the breech, just normal headspace procedure. They originally used Thompson barrels after all.

The outer casing will end up about 15" long and about 1.75 to 2" inside. The holes in the barrel are to bleed off pressure and allow gasses to expand. The expansion chamber at rear is filled with stainless screen. The front has about 8 baffles, "K" type work fine. The Archimedean screw is a nightmare to build, I recommend against trying. Have fun with it if you do. The holes in the expansion chamber don't need to follow the grooves, unnecessary extra effort for no advantage. Inside area matters though, more inside area allows more gas expansion and will be quieter. Don't try to use slower or light load .45, they require the standard ball to seal and give optimum results.

If reading the original notes about the shot at ducks on a pond 400yd distant...forget it. Balloon juice...

[tiriaq]

A pistol caliber carbine can be made with the barrel installed as usual in a Lee Enfield, with a normal length bolt. The Delisle was not made this way.
If the bolt is shortened, as was done with the Delisle, the barrel must be brought back into the receiver to reach the bolt. The breech end of the barrel, which extends back to the bolt, is larger in diameter than a .303 bolt. The bolt way must be bored out, from the front, to accept the barrel.
Note that the breech end of the barrel is counterbored - the bolt head goes into the barrel breech a short distance. This creates a hood at the breech end of the barrel, which helps feeding.
Have a look at Promo's excellent photos. You can see how the barrel is brought back into the receiver, and that it is substantially larger in diameter than the bolt. The receiver must be bored out to accept the barrel's diameter.

[tiriaq]

Incidentally, if a Thompson barrel is used to create a Delisle, it would be used as a blank. The Thompson's breech threads are .848"-10 square, while a Lee Enfield's are 1"-14 55 degree V.
And the breeching is very different, so in addition to diametric turning and threading, the chamber would have to be reamed deeper after the barrel face was counterbored to accept the Lee Enfield bolt head and extractor..

[browningautorifle]

The Thompson's breech threads

Yes, that part is turned off and you see the breech way back inside the LE action.

And the breeching is very different,

I think you misunderstand. I speak from doing some. We threaded, made them tight to the bolt face and cut a chamber. We never sunk the bolt face into the breech like the originals, not needed. I did both short bolt and original bolt. The hard part is setting up a mag. Making a single shot is easy. The rest I spoke of is from doing them, like shop notes.

I know it's going to be hard for some to believe, I get that.

[browningautorifle]

Incidentally, if a Thompson barrel is used to create a Delisle, it would be used as a blank

I thought I should also add this from the Wiki about Delisle, they also talk about the "T" gun barrel. I'd rather use a barrel blank, no old material then.

"The De Lisle was based on a Short Magazine, Lee–Enfield Mk III* converted to .45 ACP by modifying the receiver, altering the bolt/bolthead, replacing the barrel with a modified Thompson submachine gun barrel (6 grooves, RH twist), and using modified magazines from the M1911 pistol."

[CINDERS]

[tiriaq]

Yes, that part is turned off and you see the breech way back inside the LE action.



I think you misunderstand. I speak from doing some. We threaded, made them tight to the bolt face and cut a chamber. We never sunk the bolt face into the breech like the originals, not needed. I did both short bolt and original bolt. The hard part is setting up a mag. Making a single shot is easy. The rest I spoke of is from doing them, like shop notes.

I know it's going to be hard for some to believe, I get that.

Did you bore out the receiver when you brought the barrel back to the short bolt bolt head?

[browningautorifle]

bore out the receiver

The first one, I'm pretty sure we used a vertical mill and cutter. The back end was small and the bolt face did not imbed in the breech like the original and no issues. We cut an extractor groove on the outside. That was using the short throw bolt and threading that was more trouble than it was worth. After that I used a full length bolt and it worked just fine. The original had lots done that was completely unnecessary. Lots of extra work.