My favorite carbine load is my 300 gr. Hornady XTP magnum with 21 gr. Reloader7 or the 250 gr. XTP with 23 gr. Reloader7. I use CCI large rifle primers and they really reach out with some authority, but barely kick in my 6 lb Buffalo Classic carbine with a 20" barrel. I'm using them on whitetails this year. They only thing I do special is use an orange sharpie and color the primer and a ring on the bullet to make sure I don't load them into my blackhawk and I keep them in a separate orange bullet case. It doesn't hurt the blackhawk, but the 5.5" barrel doesn't allow the powder to all burn, so you get a good flash. 
