Your 14 Get a 12 Gaugeim 13 going on 14 in september i been shooting my uncles beneli with 3 inch loads since i was 11 man im 5'5 and 130 u should be able to at least handle a 12 gauge with 2 3/4 loads and then when u get use to it go to the 3 inch loads......Or if that dont work out im sure u wont have any problem shooting the 20 gauge with 2 3/4 is has about as much kick as a 270 win and with the 3 inch loads man they kick like a 12 gauge with 2 3/4 loads.......No problems