Mark with out seeing the case history I can't say for certain, but i can hazard a guess that SP started the patent based upon their freak system, but as the Aradus product came onto the market they changed the claims to incorporate how it works.
That's actually perfectly legal if the claims still fit within their original description, and I have no problem with that practice (done it myself
)
But I do have a problem with the patent because in my opinion they shouldn't be allowed claim one which is clearly already in the public domain from other products that you also note.
You are not supposed to make or have a claim granted that is broad enough to capture public domain products that were available before you filed the patent. The USPTO is supposed
to pick up on it and not allow such broad claims. You are also not supposed to knowingly submit them if you know there is prior art.
You are supposed to disclose all prior art and 'known inventions'.
I wonder if now would be a good time to state the age of the guy doing the 'examining' for SP's gun patents, his experience, how long he is out of his time, and where he lives? Nah that would just be rumour huh Rancid?
The more you know the more the plot thickens.