Guidance on De Lisle build

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DJLaunchCodes
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Guidance on De Lisle build

Post by DJLaunchCodes »

Hello all, new member here! I've been lurking for some time now, doing research for my De Lisle inspired build. This will be my first suppressor and first form 1, I feel as though I'm in a little over my head at this point but I already have the enfield action and I'm committed to seeing this through. If this isn't the right place to ask please let me know.

I'm looking for ideas on a few design challenges I have encountered:

1) I don't have a ton of experience machining, and considering the eccentric design of the original De Lisle (to which I'd like to stay true, at least externally) I don't feel confident that I can machine eccentric baffles. I have considered either a traditional monocore design, a 3D-printed radial or conical baffle stack, or replicating the original interrupted screw baffles of the De Lisle. From what I have read, a traditional monocore will not be as effective as a radial or conical baffle stack, but seems to be the easiest route for a 1-stamp gun since I can permanently affix the monocore to the barrel. I have a lot of experience 3D printing, and I am confident a baffle stack printed in PLA+ or Nylon would be sufficient enough to last under the low pressures of .45ACP when combined with a metal blast baffle. Lastly, I've read the original De Lisles had accuracy issues due to their interrupted screw baffles and guide rods. This design doesn't seem like it would be near as effective as a more modern design.

2) If I go with the 3d-printed baffle stack, is there a proven way to keep the baffles timed with the barrel? I originally was just going to have two guide rods running through the baffles like the original but I have become concerned with the rigidity of this setup.

3) Probably a stupid question, but does it make sense to affix the rear endcap to the receiver? I will be using a rhineland arms barrel, so I intend to first sandwich the rear endcap between the receiver and the savage-style locking ring on the barrel, and then either insert bolts through the inside of the endcap into the receiver, or just weld it together. I figured this would ensure the endcap provides a solid mounting point for the outer suppressor tube and the guide rods for the baffles, as well as help keep everything timed properly.

4) Another stupid question I'm sure, but can somebody explain what it means for the barrel to be tensioned to the suppressor, and why that is important? It's something I've seen mentioned around here. I think I understand it but I just want to make sure.

5) Lastly, is there an effective DIY method to port a barrel without producing burrs? I've heard one can use cerrosafe or lead to fill the barrel and give the bit something to bite into after clearing the inner surface of the barrel. I've heard of EDM porting, but ideally I'd like to do this myself.


Thank you all!
Historian
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Re: Guidance on De Lisle build

Post by Historian »

May I direct you to nfatalk.org site where there is
a cornucopia on De Lisle information including
some enviably talented folk's detailed build.
For example the wood forming block for making
the baffles.

E.g., << http://nfatalk.org/forum/showthread.php ... ht=Delisle >>

<< https://www.youtube.com/watch?v=Iv6C5GjUPt8 >>

Easy to sign up to an excellent site.

Please share your eventual build with us.


Best.
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Capt. Link.
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Re: Guidance on De Lisle build

Post by Capt. Link. »

While you may be confident on printing baffles if you are wrong the cost is another tax stamp to fix it. You can do much better than tie rods as that was the glitch in accuracy of the original.Timing is not a problem if you build a coaxial design with a eccentric outer tube. Tension of the barrel/suppressor is key to a sturdy build.Skip the porting as its not required.You can port without burrs by using a sharp reamer to finish the hole.You can eliminate existing burrs with a lead lap or by using Craytex.
We have learned allot about integral design since WW2. Barrels must be supported and held in alignment with the suppression tube.
Basic layout is a suppression tube is fitted around the receiver making it the end cap.A short barrel 10.00" is held in tension to the suppression tube.Three eccentric rings hold the outer tube.The first is affixed to the receiver,the second at the suppression tube/barrel junction,the third is the end cap.Last is the outer eccentric shell. While my description is simplified it is a proven one.
-CL
The only reason after 243 years the government now wants to disarm you is they intend to do something you would shoot them for!
http://www.silencertalk.com/forum/viewtopic.php?f=10&t=79895
a_canadian
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Re: Guidance on De Lisle build

Post by a_canadian »

DJLaunchCodes wrote: 1) I have a lot of experience 3D printing, and I am confident a baffle stack printed in PLA+ or Nylon would be sufficient enough to last under the low pressures of .45ACP when combined with a metal blast baffle.
Having made a number of monocores of Delrin (melting point 177°C) and a Ertalyte (melting point 259°C) for .22lr subsonic slow fire applications using short barrels (between 4" and 11") and having seen minor heat damage with both plastics, my guess would be that .45ACP with low temperature plastics like nylon (melting point between 230°C and 290°C for various nylon6 varieties) or PLA+ filament (melting point between 205°С and 230°С) would be similarly useful for only occasional use. This is a bolt rifle you're talking about, so perhaps usable, but not ideal even with a metal blast baffle. Perhaps as the second half of the baffle stack you'd be safe enough as most flame is happening in the first half with subsonics. As long as you're 3D printing, I'd recommend going with something like a string of K baffles but all in one piece, after at least 2 or 3 metal baffles.
DJLaunchCodes wrote:2) If I go with the 3d-printed baffle stack, is there a proven way to keep the baffles timed with the barrel? I originally was just going to have two guide rods running through the baffles like the original but I have become concerned with the rigidity of this setup.
Just print the stack as a unit and you won't have much to worry about with rotation, unless it's hard to find a way to keep the one-piece stack from rotating. A feature printed at one end keying into something matched in the tube would work, even if it's just a couple of notches with bolts going into them. You could thread in your front end cap then bore through the tube and through that into recesses in the printed core, using flat head machine screws to bring them flush in full-size holes in the tube which stops against threaded holes in the cap.
DJLaunchCodes wrote:5) Lastly, is there an effective DIY method to port a barrel without producing burrs? I've heard one can use cerrosafe or lead to fill the barrel and give the bit something to bite into after clearing the inner surface of the barrel. I've heard of EDM porting, but ideally I'd like to do this myself.
I've found, for a couple of 9mm barrels with integral suppressors, that it's simplest to just drill the ports at 45° to the barrel, the exit of each hole finishing towards the muzzle. The slight burrs resulting are knocked flush by the first bullet fired. Then I can follow up with a small diamond file to deburr. A couple of cycles of shoot-file-shoot-file results in clean edges, but even without cleaning them up the bore looks smooth after shooting very little and patches pull through cleanly from the chamber with no fibres catching. Drilling at this angle prevents shaving any jackets - my cans show zero metal collected.
Historian
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Re: Guidance on De Lisle build

Post by Historian »

A_Canadian's and The Good Captain's most lucid and informative
responses above are the reason this site is unique. The corporate
knowledge base and the free and happy sharing are inspiring.

It reminded me of a little known 1967 'gun-smithing-kink' I gleaned from
a Canadian mathematical physicist, Dr. Donald Foster, who came in second in the 1938 Camp Perry long
distance rifle shooting at 1,000 yards with a WW1 Springfield rifle with iron sights.
The barrel on his Springfield was a Star-Guage barrel**.

"...The winner had used high power scope..."

He kindly let me take it to the range once. The action was incredibly smooth
and effortless.

The only other time I held an action even more polished/smoother was at our 'home office' in D.C. late 1970's
when in the lobby gunnery Sergeants from the Marine Corps showed their coterie of arms, including
a bolt action sniper rifle. Everything moved as effortlessly as if on polished
and lubricated glass. Breath taking. Finger tip light.

Don's 'gun-smithing-kink' consisted of firing a few magazines of armor piercing rounds
through a weapon. They polished the barrel and removed any small burrs that rifling created.
This truly surprised me as one would have assumed the opposite, that the tough rounds would have instead
a deleterious effect. In keeping with the wisdom given above of the two luminaries. Do they make armor piercing
rounds for small caliber?

Best.


** << http://www.hallowellco.com/star_guaged_barrels.htm >>
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Capt. Link.
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Re: Guidance on De Lisle build

Post by Capt. Link. »

I don't think the AP core ever comes in contact with the barrel to size or "BALL" a bore to spec. The bullet jackets may be thicker or or softer than standard ammo to help a initial polish. I wonder if he also dipped the bullets in grease. (a common practice)
A technique known as lapping to gain a consistent size while smoothing the barrel is used today along with fire lapping. The latter embeds a abrasive into bullets before they are fired. Both of these techniques require knowledge and skill that is beyond what can be printed.
AP has been made in various small calibers. 38 special, .45acp, .22LR to name a few pistol calibers. All US military rifle calibers are available with AP bullets. AP loads are even made for the 12gage.

The 03 rifle is smooth & accurate with adjustable sights. I encourage you to cycle a 30-40 Krag action as they are even smoother.
-CL
The only reason after 243 years the government now wants to disarm you is they intend to do something you would shoot them for!
http://www.silencertalk.com/forum/viewtopic.php?f=10&t=79895
Rich V
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Re: Guidance on De Lisle build

Post by Rich V »

DJLaunchCodes wrote: Tue Mar 16, 2021 4:50 pm


1) I don't have a ton of experience machining,


Thank you all!
The De Lisle is a very complicated build and is a challenge to those with a lot of gunsmith experience. The Enfield action will need a lot of modification, you will need to build or modify an existing magazine for it and the suppressor is a real challenge to get proper alignment. Add to that there is no detailed plans/prints so you will be "winging it" for a lot of the build. All of this I know because a good friend and very experienced gunsmith built one. Yes it's a great, quiet platform and very iconic but in his words " If I knew what I was getting into I would never started down that road". That coming from a guy who modified his M60 to shoot 223 and 300BLK, and build a 1919A4 that shoots 45ACP.

With little experience in machining you will fail in this endeavor. I suggest you use your form 1 stamp to build a simple suppressor from one of the designs found on this forum.
I hate to crash your dream but it's kinder than have you fail after a lot of effort and $$.
DJLaunchCodes
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Re: Guidance on De Lisle build

Post by DJLaunchCodes »

Thank you all. Seems like I have definitely bitten off more than I can chew. My new plan is to do a more traditional form 1 integral suppressor with the rhineland arms barrel. It won’t look anything like the original De Lisle but sounds like I’ll be saving myself a ton of time, money, and headache!
0101silent
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Re: Guidance on De Lisle build

Post by 0101silent »

John A recently completed a traditional delisle style rifle. It's worth taking a look at. https://form1suppressor.boards.net/thre ... ine?page=6

That forum has evolved from freeze plugs and valve spring retainers to solvent traps, mini lathes, real machinists, and interesting baffle designs.
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