need help/advice on 7615 jamming

[jdk829]

i just purchased a 7615 ranch carbine. i am having jamming problems, and i have tried several types of ammo. it appears as though the spent cartridge is not being property ejected, because it will often jam on the last round, with the spent shell getting "pinched" by not exiting properly as the action closes. it will jam at least every five rounds. i've have over 1000 rounds through my other 7615 without a single jam, and that's why i purchased a second. so, i don't think it is operator error. any suggestions, other than sending it back for warranty? also, it rarely jams when i just cycle rounds through w/o firing. it's almost as if the spent shell casing has expanded in the chamber and is getting stuck. thank you.