Right, so you're saying it isn't classified as an airsoft gun because it fires more than one bb per pull of trigger, and each bb flying at even 200fps would mean that the total joule output is over 1.3J for multi shot, or even 2.5J for single shot (if it were classified as such.) The only thing I have an issue with, is the fact that these are multiple shots of (as you said) .65J each. So while the total energy output is (much likely more than 12x.65J as a lot of the air is simply wasted/pushing the wad) more than 1.3J, each shot is less than 1.3J, pretty much the same as having a 300fps (on .2g) m4 with a crazy ROF. It's essentially the same thing: loads of bbs with one pull of the trigger each travelling below the limit. Therefore I think it should fall under the same classification/ be even safer, since these bbs are flying slower anyway. Unless they want to go and ban high ROF AEGs as well just for the sake of it at this point. Moreover, the bbs don't even arrive at the target in the same spot/ at the same time. It's likely that a high ROF AEG can probably get more bbs to hit a target in the same amount of time it takes for the shot to travel from the shotgun to the target.
I'm not saying that's how the government sees it, but that's what makes sense to me from a logical standpoint, using their guidelines, and perhaps could be argued in court (assuming my logic is correct), if it ever got that bad in the first place. See below:
Exception for airsoft guns
(1)An “airsoft gun” is not to be regarded as a firearm for the purposes of this Act.
(2)An “airsoft gun” is a barrelled weapon of any description which—
(a)is designed to discharge only a small plastic missile (whether or not it is also capable of discharging any other kind of missile), and <---this is true for the CAM 870, it's designed to use plastic bbs, even if you can use other projectiles, e.g. wax slug
(b)is not capable of discharging a missile (of any kind) with kinetic energy at the muzzle of the weapon that exceeds the permitted level. <----this might be a problem, since it is capable of firing slugs, which will almost definitely pass the joule limit : https://www.youtube.com/watch?v=ah8K7b4QQd0 skip to 4 minutes in
(3)“Small plastic missile” means a missile that—
(a)is made wholly or partly from plastics, <---yep
(b)is spherical, and <---yep
(c)does not exceed 8 millimetres in diameter. <---yep
(4)The permitted kinetic energy level is—
(a)in the case of a weapon which is capable of discharging two or more missiles successively without repeated pressure on the trigger, 1.3 joules; <---already gave my opinion on this, the shots are successive since they don't reach the target at the same time, and all go in one trigger pull, each one is less than 1.3J so should be ok.
(b)in any other case, 2.5 joules.” <--- is not meant to fire only one projectile, but depending on size/seal with shell and barrel, it can potentially pass this.
Reviewing all this information it looks to me like the only issue with the gun is that it is capable of firing well above the joule limit. However, this is only possible with projectiles it wasn't designed to fire, in which case the legality is shady, because the GOV have this whole thing about replicas being readily convertible to firearms being illegal. Now, whilst it would not be possible to convert this into a M870, the problem arises due to the fact that the GOV classify any successive shot gun capable of over 1.3J as a firearm, so it would be readily convertible.
But, there is a silver lining (I think.) The above statement may not be cause for concern, because; when firing a slug (which you wouldn't do in public/at a game anyway), you are only discharging one round, even if it isn't a sub 8mm plastic bb, so it is capable of shooting a single shot of any kind above 2.5J (as it now falls into this category.) The silver lining is here. I'm almost certain that if a single shot airsoft gun fires above 2.5J, then it is classified as an air rifle, just as with paintball guns, not a section 5 firearm, unless it is more powerful than 16.25J - which may still be a problem for this gun , but you can get around that potentially by messing with the seals in the shells or the mass of the slugs themselves if you were that way inclined. However, I still don't see this being a problem, because it is highly unlikely that - in the unlikely event of a trial, the gun would be tested with perfectly fitting wax slugs. More likely it would be tried with bbs, maybe some other larger ammo, idk. It's difficult to say with this gun, and I'm surprised it wasn't banned anyway under the Brocock ban anyway, maybe because it doesn't fire lead pellet, even though it can - if anyone knows, please do tell, because the aps m40 wasn't exempted from this ban, yet you see many retailers selling this gun.
If anyone can find flaws in my thinking, please do point them out, because I'm looking to get the Salient Arms version, and I don't want to spend any money on something illegal , let alone £600.
Reviewing the evidence, it looks like the gun should be ok, depending on how the GOV would test it if taken in for whatever reason (travelling to and from games etc.) However, where it could fail is in the legal grey areas of:
A)If it is classified as an airgun, due to its ability to fire single shots above 2.5J, then you're shooting people in the woods/CQB with it (even though you're shooting plastic bbs below this limit), and that might be a problem.
B)If it meets their stupid "readily convertible" qualification that all gas gun users have to be worried about, as a HPA set up could be cranked up, although the shells have a limited capacity for CO2, so maybe not.
C)If they for whatever illogical reason, consider the combined energy of all the shot coming out as the muzzle energy, which would make no sense, but then again they've not shown us that this whole thing has been handled with a whole lot of sense, then this would definitely fall into the S5 firearm category. It's sad that AEG users (not quick change spring) and bolt action springers are not as worried about this thing as GBB users, we should really stick closer together as a community if we are to survive. Reminds me of that "First they came for the Jews" poem you always seem to hear in scenarios like this. Bit dramatic, I know, but I'd hate to lose whatever is left of my right to go pew pew in the forest because some politician wants to look good.
D)Again with the testing, would firing a single shot of wax or a bigger rubber ball even be able to stand against you? I say this because the energy requirements are for "missiles", in which case, more than 2.5J makes the gun fall into airgun territory, like paintball, unless it fires more than 16.25J.
TLDR: legal stuff is confusing, we have legal clarification for most airsoft guns to be safe under the new bill, but it's not clear enough by any stretch of the imagination.
Please do read tediously long post to identify any issues with my thinking. If you made it through that, well done.