This is a project called "Armadas 1500 II". It is a weapon that works with an integrated air pump, it is a single shot, hybrid that precompresses at 8X - 10X. The firing barrel is with 12 microgrooves, caliber .25 and fires common pellets. The inverted bolt is made of 1045 steel, the combustion cham...

An empty CO2 capsule averages at around 30 grams, so muzzle energy for those first tests at 2500 psi was in the 45 ft lbs range. In the interest of ramping things up further, I "made" a better projectile by cutting down a 12g capsule to an inch in length, now weighing in at 10 grams: https://i.imgur...

yyt wrote: ↑

Wed Jan 11, 2023 9:51 pm

Do you think a self-made epoxy spark plug can work better?

I would make something like that:
Using this sort of fitting:
Yellow is a plastic cup or similar insulator, glue to the fitting, stick your electrode through then pour marine epoxy.

You need something to induce turbulence! Some experimentation was definitely in order, so I machined a Delrin cup to fit the chamber with a 1/4" orifice through the base: 20231206_213324.jpg baffling.png I fired a series of shots and the results were quite interesting. The first thing I did was rep...

A mesh screen would kick up turbulence but also suck up a lot of heat. We have discussed before if running the chamber fan during firing might increase the burn speed. Way back when I measured burn speed in a closed chamber at 1x with/without the fan running and with one or three sparks gaps. There...

Here are photos of 2 test shots done today, in Feet Per Second

Done at 2000psi The mass of this last shot is 147grain. This gives an energy of ~230ftlb. Not too shabby for a bit under half pressure.

The airsoft barrel slides inside the Nerf barrel and clamps at the front, changed the front grip and the charge handle again. Orange muzzle. Will put a foam dart into single layer corrugated cardboard.

As it turns out it goes at 320-ish feet per second or 97 meters per second, still pretty solid for a second build, especially when I load it with a dart round or regular spuds still mauling a rotting tree stump 202412%Friday20092544.png However for the incomplete combustion issue, I could just add a...