Ah, you made it :) Welcome to the forum! A lot more sophisticated design than I was expecting. I really like the double action trigger, very clever! I suppose the biggest disadvantage though is that it is not easily adjustable, so for example you could be dumping a lot more air per shot than is nece...

Some balanced valve development: https://i.imgur.com/hRYtNSph.jpg Balanced valve V1 and housing compared to the improved poppet and original housing. Note the groove at the head of the valve to allow air to vent into the balanced portion. The head diameter is also reduced to 6mm from 8mm for better ...

Nice! It's going to be great seeing it in action with the alternating barrels, especially if the rate of fire is low enough to be able to perceive it.

Good improvement! More than 900 fps with that lead ball? steel? You can see the ammunition here , 0.310" diameter lead balls that weigh about 2.9 grams. The debated but still quite valid rule of thumb for the minimum energy required for a kinetic projectile to reliably produce a potentially lethal ...

I got a serious engineering job out of school and that's moved me into an apartment and diverted my attention towards some more electronic/computer projects Been there... it will get better! I like the idea of a captive piston with some serious venting at the front of the barrel. I'm imagining the ...

More balanced valve development: https://i.imgur.com/jh1PIxrh.jpg Version 2.1 with a stronger spring and a shoulder that bottoms out before the base of the valve hits the end of the balance chamber. At 1100 psi, again using 45 grain 0.310" lead balls, the chrono read 789 fps for 62.2 ft lbs. At 1500...

Those numbers are looking pretty crazy! We're definitely in modern big bore airgun territory :) It turns out there's a book that looks at these devices in detail, "Construction and Operation of the Air Gun Volume 2 - The Walking Stick Air Gun" The performance listed for a similar muzzle-loading air...

That's what I mean when I say that mechanics always teach me something, when I do tests, and I think that most of the time, first there is the fact and then the law My style of engineering tends to be... "optimistic" ... so it usually takes a few tries before I do it properly, the way I ought to ha...

hectmarr wrote: ↑

Fri Mar 05, 2021 10:05 am

As my dad used to say, new wine in old jars.

A true poet, I like this expression

It is impossible to stop thinking about what the captive piston can suck, due to its inertia mass, from the back, after expelling the projectile, perhaps a measure of combustible gas. 8-) I had no idea about this kind of technique, it seems simple to me and it works very well. With the same combina...

An idle thought that is basically the unholy marriage of a nailgun and paintball marker: https://i.imgur.com/LqY0rAO.gif The benefit is that it will fire whatever fits in the barrel and it doesn't need to be airtight, indeed it could be fed though a hopper of shot of whatever size doesn't fall thoug...

"if it only fires one shot I am not interested"

Classic Hector

I think we had started down that road here...

Damage video just to wrap things up, this thing is a lot of fun!

You... you want to hook up a BBMG to a jet engine? That sounds like a plan, I love it! So you would have the engine running continuously and redirect the flow into the BB chamber when you want to fire? That thing is going to get hot though, I don't think epoxied fittings will last... will you be usi...

As some people are already aware, adding an airtight detent to the breech of a BB machinegun is a good way of boosting power as it allows pressure to build up in the BB chamber before the projectile is fired, translating into higher muzzle velocities. The downside is that in most cases, a second BB ...