SAZ,
The XTI-50 was not designed to go above 12 FPE. It was made for World Field Target and Hunter Field Target rules (not AAFTA rules) under 12 FPE power limit.
For a slightly greater amount of money, I would buy an American made Thomas air rifle. The Thomas is made for the American market not European one.
I shot the prototype XTI-50 rifle when I shot the 2019 Worlds in England. I was really impressed with it because it comes with all of the accessories that one needs to compete in WFTF class.
Leo