Larger bore on thread adapter compared to suppressor and firearm?

I have a 22 pistol (GSG-5PK) and a Silencerco Sparrow can. As some of you may know, finding adapters for the weird, metric threads on the GSG is hit or miss but I picked one up recently that was advertised as a being for the GSG-5PK and based on the H&K MP5K design. Here's the link:
https://www.hkspecialiststore.com/pr...e&pageNumber=2

Upon receiving it, I found that the adapter actually has a 9mm bore, not a 22 bore. If I were going from a 22 barrel to a 9mm adapter to a 9mm (or larger) can, I wouldn't worry to much, but going back down to a 22 can concerns me a bit.

Is this a valid concern? Should I send it back or not worry about it?

For the record, there's another issue with the can as well but I believe I can fix that. The threaded end (for the can) is too long so the can doesn't actually seat down on the shoulder of the adapter. My thought on that is to simply turn it down so the last little bit isn't threaded (as per the Silencerco specs, so it can engage the o-ring), or cut the entire threaded portion down to a more nominal length. Either way, that would allow the can to seat on the shoulder. The fact that there's two issues with this adapter is enough to make me nervous but like I said, I've had a hell of a time finding an adapter at all. If I can make it work SAFELY, I'm all for it.

Bore size is a non issue as long as the bullet doesn't hit the adapter. The can not seating on the shoulder is an issue . I'd have the adapter machined to the can manufacturers specs. Check the alignment when it's all done to make sure there won't be baffle strikes .