Just get yourself a Browning Micro. I can seat bullets at any length I desire, including plastic-tipped ones just barely inside the neck, and they still fit the magazine and feed. The single-stack magazine only gives me 3+1 capacity, but I happily trade that for the long usable length of the rounds.
Mine also shoots almost any bullet into sub-inch and will plunk the best of them into 0.6" on no-wind days. Absolutely my favorite rifle.
