your grouping at 30m should be dinner plate sized at most, there's definitely something going on.
you say the FPS is between 290 and 315, does it jump about in that range between shots or is that just from 2 separate occasions at a chrono? if it's not consistently shooting with a 5-10fps variance or less you've most likely got an air seal issue somewhere.
I'd also recommend having a good look at your hop rubber, a worn or ripped (even the tiniest amount) rubber can cause huge accuracy issues.
Cleaning the barrel is of course a standard maintenance thing, I expect you've already done it, if not, give it a go, it'll help.
However, if the gun's still in-warranty, call the retailer and ask them what to do about it. Most likely they'll say that guns deteriorate over time and that it's standard wear and tear, depending on how long you've had it and how much you've used it they may be right. They'll almost certainly be able to offer to give it a bit of a tune-up and get it back to new though.