We don’t expect a barrel to let go after a few hundred rounds or a few thousand or a few tens of thousands, so why should we expect any part of a moderator, or the thread etc. to only last a few hundred rounds?
Because that would be totally unrealistic in the real world. Mods are not like barrels. Don't confuse yourself, they do an utterly different job. If you want one to last forever and have an idea how to do it and still be practical, go ahead.
Even then, say I shot out a barrel and had it replaced, would I try to still use the same mod on the new barrel. Well of course I would. Providing it still looked fit, why ever not.
If I was super-cautious, maybe I'd send it back to London (established 1675) or Birmingham (1813, the new boys) for re-proof according to their established methodology. I am being sarcastic BTW.
Really they understand nothing about anything except barrels and the other pressure bearing parts of say a rifle's action. Not that that stopped them from trying a grab at insisting that mods were something that fell within their remit.
That said, our military do insist on it, not just for mods but even muzzle brakes and other muzzle devices. But these are used in specific applications, with specific ammunition so it's not comparable with the randomness of the civilian market.
I've even observed a shipment of GPMGs being proofed at one of our ranges. 25 ISTR, each supplied with two barrels, which were matched to each and accuracy tested before the proof man put two oiled proof rounds through each, gave them a look over and some gauging, then took out his hammer and punches and declared them good. That was the mornings work. Then came the proofing of a shedload of spare barrels, one at a time on a different gun (not one of the new ones for delivery) Fit barrel, two oiled proof rounds. Take off, inspect stamp. Quite a rhythm going, the proof man was kept continuously busy all day.
Not really a job for say Birmingham Proof House.
Might be a silly question but here it goes - What could go wrong if an ultrasonic cleaner was to be used to clean those moderators that cannot be disassembled. Would it ruin it completely or is it worth a try in case of a mode which has only metal parts? Just cuirous and probably better to ask in here than ruining a good mod.
Quite possibly, if it was an aluminium thing, anodised, you could ruin the anodising. Used to work in motorsport at a high level. There were parts that were US cleaned, and others that were verboten. Such as anything anodised aluminium. Mind you the US cleaners were mightily powerful, nothing remotely close to what you might read about on here for case cleaning etc.
Whole engine blocks, cylinder heads, gearbox casings, then all the smaller bits, cranks, conrods, gears, and so on. Used to be that we would do this after every race. Nowadays the F1 lot are only allowed so many engines/season so can't rebuild them after every race. As we used to do.
Lots of HSE stuff for anyone going near one, or operating it.
If made of steel throughout, go for it. Mind you I wouldn't expect much to happen on the inside of one of those with a typical mincy little US cleaner that can barely get crud out of primer pockets on more than a handful of brass.