Hey Dan, where did you order yours from that it has a 10 shot mag? Both my mags are 8 shots. I got mine from https://www.aeaairgunus.com/
The most important thing about buying an AEA airgun seems to me to be WHO you buy one from rather than what you buy. There are at least 3 different dealers in the USA that I know of off the top of my head and one of them, Bin-Lu at PCPcom.us. (SigShooter on YouTube) has complaints about his poor customer service and things like shipping guns without magazine, making promises he does not keep, etc. I would not recommend buying from him. I bought mine from https://www.aeaairgunus.com/ and have been happy with it. At least 2 others on GTA have bought theirs from the same company. That one I can recommend.Then there is Zachary at aresairgunstactical.com. Some of his customers are on GTA and have been happy with his company.
I just watched a video Mr. Hollowpoint did on the Challenger with the long barrel in .30, and that gun was making some insane power numbers on a 4500 psi fill. He said the maker did confirm the cylinder/gun could take that pressure safely. I don't remember the exact numbers, but he was getting well over 200 fpe with 82 grain slugs in .30! Seems like it was shooting them at like 1080 fps I can't comment on reliability or accuracy at those power levels, but those power figures are just crazy for a .30. Seems like the long barreled challenger would be the way to go, if you just wanted a hammer of a gun though.