Re: Tight lipped and ashen faced re 338 LM at Silverdale
Actually... the 'High Muzzle Energy' restrictions cause some grief even for 'bullseye' shooters - a .308 Winchester driving a 155gr projectile @ anything even slightly over 3100fps runs afoul of that limit. A couple people on the U.S. team over visiting Bisley recently had to de-tune their loads a bit to stay under that limit.
As mentioned, the reason is to provide some documentation that the range is doing its part to make sure bullets stay on the property and avoid litigation from outside bodies (in general, not sure about the MoD issues); other places it has to do with the big gonzo calibers just plain tearing up the backstops. The problem is that as with most 'one size fits all' policies, its not always thought through all the way, or the people implementing it never dreamed of what seem to us (after the fact) like perfectly obvious scenarios where the rule is overly restrictive or just plain silly (to us).
Instead of being a smart ***** and circumventing the rules by way of headstamp (as someone mentioned earlier), I'd get in touch with the people making the rules, find out exactly what the objections are. See if you can find a way to talk to them, and explain your case (hopefully without getting *other* calibers banned as well). Get like minded shooters together and start lobbying, then boycotting if necessary. Try to work with the club to get the necessary down-range impact area purchased, etc.
In short, be part of the solution, not part of the problem.