It looks like he's using 3 18650's in series so I would go ahead and wager most 3S RC batteries could do the job.

If you're right. I'm going to try to get a harder o'ring, as a first alternative solution. The second may be, why not? what you propose, make a thread in the place of the o'ring groove, and a small plate with some material to seal the exit of the combustion chamber. For now I have to try another har...

Thanks for the explanation. Now I get it. Like you said, the o-ring isn't supported from the outside, so it stretches and just comes off the rod when you shoot it. I agree that a harder o-ring is the best experiment to try next. If all else fails, you can try to modify the valve with a sealing face ...

I understand what you tell me. Actually the small o'ring does not touch anything. It is built as in the drawing. The o'ring fits into a 6.5 mm bronze tube with a conical mouthpiece and all well mirror polished, when moved to the left, (in the drawing), to seal the combustion chamber. When combustion...

Here are the photos of how it is inside. Here are the photos of how it is inside.

Does the small o-ring pass over a port while under pressure? If so, it's like running the o-ring over a cheese grater. You might try a different shaped o-ring, such as the X shaped ones. They have much less friction when squeezed, but there would still be friction caused by pressure. They might work...

Well, the valve was tested but it has a drawback that makes it almost useless. I am referring to this piston valve design exclusively. The practical problem is that it does not retain the lubrication in the small 6.5 mm piston, and for this reason, the o'ring breaks ... Perhaps the solution is to in...

So, spent some time stripping down a bit. Managed to unblock the tooling and the Z axis, (hooray for hand winches), loking at the scraping marks on the slideways and gibs I thought to myself "that's been rescraped", but given the way the gibs fit, I'd be surprised if it's done many hours from new. D...

It's been a while that I've been looking for a smallish milling machine to go with my smallish lathe(s). Yes, I am aware that the chinese make some fairly capable small milling machines. But I simply don't like them. Horrible yucky plastic tat. Id far rather something made of great big chunks of cas...

I've been thinking (uh oh) again about barrels. First, rifled chokes. I have a scrap .22 cal that maybe could be used as a rifled choke on the end of a smoothbore barrel. There is a hypothesis that a high speed slug slamming into the rifling might be bad for accuracy, but at pneumatic velocities pro...

Finally got somewhere to hang stuff, need more hooks (less guns) this was my first attempt at arranging so it could change

The damage video was fun to watch. This was a great project.

Yes, I am bumping this thread because I missed the final product after my annoying suggestions. Great work as always!

So interesting! I was also considering modifying a current coax muzzleloader to have a longer barrel... if successful there is huge potential for adding rifling or choke or simply barrel length.

I had the valve and the entire bolt system of the weapon that I am planning built by a turner. I actually drew everything in detail, and measurements, exact, and I passed it to him.
It is not a very neat job, but it works fast and it pays quite little, it is what it is.