Spot on Col
I also don't subscribe to this idea that there might be some demon forensic lab out there willing to do anything to put a gun over the limit to secure a conviction and make money.
If any lab does something to a seized gun to put it over the limit, that if done to any other gun available in the shops would also put them over the limit, then they've instantly opened themselves up for a very good defence. A half decent barrister would rip them a new one in court.
In some circumstances having AT fitted to your gun could also give you an additional defence in court (in casting doubt on a demon forensic labs procedures).
Don't forget in our legal system, a forensic lab has to prove your gun is 'capable' beyond any reasonable doubt. All your barrister has to do is raise a reasonable doubt about the procedures.
If you have a gun that can be adjusted for power externally with simple tools then I think pretty much all of your defence arguments are blown out of the water, so you're at the most risk. I still don't think that risk is a significant one though. In Matt's case where he has a Steyr with external power adjuster and his neighbours are unhappy about him shooting in his back garden - personally, I'd stop shooting in the back garden first and foremost, pop round to the neighbour in question and make the peace with them and also perhaps consider having the adjuster removed. Once you're known in the neighbourhood as being someone with an airgun, if there are ever any incidents of misuse in the area the finger of blame automatically points to you, so you're putting yourself at greater risk of a visit from the police and a subsequent seizure.
I've had 2 Steyr's - neither of them had external power adjusters and neither of them needed it.
I'm against lobbying government for a change to the law because I don't believe it would ultimately be a change for the better.
I believe that AT was introduced to protect the revenue of the manufacturers first and foremost and not to help customers. I believe that with a little more thought, it could have done both - the manufacturers could do a lot more to help us and in turn help themselves. If anyone is really concerned about this issue and wants to force the manufacturers to do more to help us - give them a call and say you're thinking of buying a new gun from them, and ask if they'll remove the AT. If they say no, tell them in that case you'll look elsewhere for a gun.