Im designing a prototype smoke projectile for 38mm launchers. This is designed around using a 38mm 12" barrel for the Odin Launcher. The smoke composition will be TPA based. I’m going to attempt an IR/Thermal blocking smoke composition but if all else fails it will be the same TPA composition that Invention Incarnate uses.
Design Highlights:
- Von Kármán ogive nose cone, optimal for subsonic projectiles.
- Polygonal rifled integrated pusher using an extended 4.5" Mathetatics & AWCY? M.I.L.C shell, provides initial rotation.
- 6 curved folding fins, spring loaded for stabilization and further rotation during flight.
- 3D printed housing using a DIY phenolic liner for heat mitigation.
- Helical igniter for full core ignition.
This will be a bore-riding projectile for an increased gas seal and accuracy. The 4.5" shell will cover the fins when folded so that they’re captive.
I’ve ran this through a few AI models who have calculated that with 87g of a smoke composition this projectile could reach a theoretical 45° launch distance of 160-200m at a muzzle velocity of 240-275fps.
Looking for thoughts and suggestions. Of course this design can be scaled from 26.5mm to 40mm and shortened as needed.
I’ve heard of 15mm 26.5mm 37mm and 40mm… Is there really a 38mm or do you have sausage hands ( can’t help but imagining the daddy would you like some sausages Scene from Freddy got fingered but on a computer key board instead)
Well the goto budget barrel has been a fencepost, however McMaster offers a 304 stainless steel tube thats 38mm and pressure rated to 1,600 PSI. 1 meter of this tube is around $46 so you can get several barrels out of it for cheap that will be both stronger than the fencepost and be uniformly manufactured for tighter tolerances and better gas seal. One user on the matrix has had his barrel survive some explosives going off inside of it.
Is it seamless on the inside? The most expensive and time consuming thing for me in launcher building has been removing the seams from the fence posts and conduits (for26.5mm) I’ve gone through three flex hones and got about 8 barrels total from them.
How well do they package it? I just worry it might get bent during shipping. I bought a six foot section of threaded tubing they use in the polyactico barrels and it was so bent from shipping I didn’t even get one viable barrel out of it .Package handlers in general piss me off with how appathetic they tend to be after damaging the contents your package they behave as if they have no responsibility to carefully handle or stack it and it’s the sellers fault for only placing double the packages weight in cushioning instead of three times the weight.
I dont have one in hand yet, but from what a guy in the matrix sent it looks to be “seemless” or atleast a very flat seam. McMaster lists the ID surface finish as 31 ra.
