Thanks Joe. I haven't priced the gun yet. If you're serious about getting one pm me and we'll figure something out. I've only built this one 130cm at this point.
So I shot it in the pool today. Vis was hazy 
but not as bad as it looks in the vid, I could see where the shaft hit. The target was 23ft distance from my eye. The gun is 6ft long from butt to spear tip, and my extended arm from my eye to the hand is 2ft distance. So the target was 15ft distance from the the tip of the spear.
The fish on the target is 13.5" long, so not even close to a legal mutton. The next one I'll make 16" long. This practice session was a sobering reminder that anything more than one wrap of line, with 2 x 16mm or 1 x 19mm band configuration, is wishful thinking. Unless the fish is big.
The first shot in the vid is actually the first shot I ever took with this gun. After that shot there have been a few so so shots and a couple of good ones, and those are the ones which I put in the vid. There are 4 shots on the target on the bottom left which are a bit off. Those were done with a different gun by a different person.
I haven't had a pool practice session in 5 years. I find that shooting in a pool is different/more difficult. I figured out that lining up on a real fish my forward movement and extending the arm stabilizes the gun. Whereas sitting there and trying to hold it perfectly still just makes it wobble more. I don't like shooting in the pool very much. Maybe if it was a big pool which allowed me to do a stalk before the shot would be more fun and relaxing.
About the gun, it's certainly not nose heavy, and for a 130 fairly easy to move. It seems to me watching the video, that the recoil is straight back and there's little muzzle lift before the shaft is past the muzzle. Of course a side view of the gun would better demonstrate this. All in all I feel confident about this gun and will use it.
