Right, so here's the detail of how I approached capturing the gun at the moment of firing.
I looked at several online videos of real gun being fired, like this one..
As well as the smoke, which I could do with cotton wool, there’s quite a bit of light coming out of the fireball, so I needed some small lights. They were amply supplied by Jennifer at Small Scale Lights, really good service. I got the nano led lighting package, which was everything I needed, four tiny bright leds wired up to a battery box and switch.
Then to create the projectile, I used a ball bearing, glued to a small perspex rod. The expanding cloud is a clear Christmas bauble (from amazon) which comes in two halves. I only needed to take the hanging lugs off, and drill it to accept the perspex rod.
The gun barrel was drilled to take the led wires, with an exit hole between the trunnions. This matched a hole in the body of the trail, so the wires could eventually exit at the far end of the trail.
The led’s were superglued to the perspex rod, one at the front one at the rear and two in the middle.
The clear Christmas bauble was painted in acrylic with red in the middle, shading to orange and yellow, with the ends of the bauble left clear.
Then cotton wool was stuck over the bauble with PVA glue. I found it best to use many small clumps of wool, rather than simply wrap around the whole thing. The clumps give a convincing “billow” to the smoke and the gaps between clumps allow the light to shine through.
Finally the cotton wool was sprayed with a light coat of matt black. I haven’t got an airbrush, so this was done with a rattle-can of BBQ Stove black I had in the shed. I sprayed from the rear of the gun, with a very light touch. I must say it’s this final spray that make the thing come to life, before that it really didn’t look that good.
I’m happy with the outcome, it took a bit of thinking and a couple of trial attempts but I think it looks right. My best compliment when when I showed the photo to a (non-modelling) friend and they said “Ohh have you got yourself a high-speed camera?”
Stuart