Twist Lock

Atlantis · Sat Jul 01, 2006 8:01 pm

While reading a book, this idea was presented to me, they talked about a gun with a bolt that had half it's threads stripped off to allow it to be pushed in the twisted a quarter turn to lock in place. Basically, remove 2 strips of the threading off the female and male adapters to allow the two to come together then be twsited together, allowing quick changing of threadings. This idea could also be used for a heavy duty sear, which would help with a few ideas I have.

The pic is just a visual aid of what I mean by the strips.

saladtossser · Sat Jul 01, 2006 9:06 pm

no offense but that diagram explains nothing... i made a twist lock barrel once, worked great, but not like your idea

Atlantis · Sat Jul 01, 2006 9:08 pm

Basically, this would be looking down the pipe, you would file off the blue part on both adapters, this would leave a gap in the threading for the adapters to come together, then twist.

saladtossser · Sat Jul 01, 2006 9:22 pm

if you pay attention to every thread on both fittings so they engage without problem, this is a great idea, but in my experiance plastic threads will wear away like this so use metal

Atlantis · Sat Jul 01, 2006 9:30 pm

I know this will only work if your very careful with your machining. I'm going to see if I can do this with a spare threading.

SpudStuff · Sat Jul 01, 2006 10:02 pm

that would be hard as hell to seal

boilingleadbath · Sat Jul 01, 2006 10:33 pm

Interupted thread breach block, eh?
Or I think that's the proper name, anyways...

http://www.navweaps.com/Weapons/Gun_Dat ... ed_pic.jpg

sure, try it.
So long as you leave at least one thread un-adultered, you should be good. You'll get some leakage, but it'll be accaptable so long is you don't need to hold pressure in that region.

Alternativly, we could employ our old freind: O-rings.

Atlantis · Sat Jul 01, 2006 10:34 pm

You don't need a perfect seal for a barrel. Like I said, this could also be used as a very strong sear for ideas I've had that were impossible due to lack of a strong sear.

spudshot · Sun Jul 02, 2006 12:27 am

boilingleadbath wrote:Interupted thread breach block, eh?
Or I think that's the proper name, anyways...

yep thats it, my Ithaca model 37 has interrupted threads on the barrel

Atlantis · Sun Jul 02, 2006 12:29 am

I figured it was a real thing, I was reading the book "Honor Harrington on Basiilisk Station, and they were talking about primitive rifles. It's a good book, it's about space and the future military.

Thank you for providing a more useful picture. That actually helps me as well.

FiveseveN · Sun Jul 02, 2006 7:43 pm

Yeah, that's not a bad idea. I believe it's used in Steyr's TMP.
I just love seeing firearm systems being adapted for spudgun use. It's basically just replacing pressure from the cartridge with air/combustion gas pressure.
BUT unless you use a full auto design with this system, a simple groove bolt-action seems better overall. A rubber/neoprene gasket glued at the bolt/breech end would also help.

adtchuck · Tue Jul 11, 2006 8:37 pm

This looks like a great option for a bolt action gun/cannon. With an oring at the front of the bolt I think you would cut out any leaks, or at least most of them. I think I might give this a try in a 2in rigid aluminum pipe. Machine out 1/2 a coupler, then thead the barrel on one end without removing any threads from it, and some pipe dope to help seal it, or once I know it works, perhaps even epoxy, with a fiberglass wrap around the barrel side. I will have to draw it up still, but I have the picture in my head how it should look. I have a lathe and a mill, so I get the threads cut out fairly precisely, and the couplers are fairly cheap in case I do screw one up. I will get back to you on any progress I may make.
Chuck

drac · Tue Jul 11, 2006 9:26 pm

adtchuck wrote:This looks like a great option for a bolt action gun/cannon. With an oring at the front of the bolt I think you would cut out any leaks, or at least most of them. I think I might give this a try in a 2in rigid aluminum pipe. Machine out 1/2 a coupler, then thead the barrel on one end without removing any threads from it, and some pipe dope to help seal it, or once I know it works, perhaps even epoxy, with a fiberglass wrap around the barrel side. I will have to draw it up still, but I have the picture in my head how it should look. I have a lathe and a mill, so I get the threads cut out fairly precisely, and the couplers are fairly cheap in case I do screw one up. I will get back to you on any progress I may make.
Chuck

I look forward to seeing this! Great first post.

adtchuck · Wed Jul 12, 2006 3:04 pm

Thank you, I have gotten as far as putting some of it to paper, I am trying to get together the materials now, I work on alot of construction site, so I like to use "srap" when I can find it, scrap for the trades is anything left over that is under 5ft long, so it may take a couple of weeks to get all the supplies.
Chuck

adtchuck · Wed Jul 12, 2006 4:27 pm

Ok here is a little sketch I did, I think that putting the lock behing the chamber will work just fine, with rigid aluminum pipe that is. Tapering a fit between the barrel and the bolt should help get a nice seal, and I figure to cut out a groove with the lathe for a couple orings as well. As for the receiver size this is a guess until I can get some stuff together and see what it will take, I know with some pipe it is close, but just hitting it with a cylinder hone can take care of minor flaws, and make for a smoother fit. Well I will be giving this a try, let me know if you have any thoughts.
Chuck