YYYIIIPPPPEEEEEEEEE
I fixed the gun.
Remembered a trials weapon I did last November and wondered if it had recoil, turned out not.
I had used recoil effect 'LAWSingle', not sure if that alone did it, but it works, sorry to have asked.
(Pity I spent last 2 days scratching my head about this to find I had done the same in the past, and solved it).
Also dinger you have some good ideas thier, I may investigates some further.
Btw the guns is the 4.5inch Mk 8 used on Royal Navy Warships from theh later 70's, only now being replaced by a more blocky version (easier to model in ofp thankfully, present one has over 1000 polys and it could have been much worse)
Oh heres a piccy btw