You did not mention what caliber the Hawken is. If it is a .54 and the twist is real slow you could still do well with a round ball or one of the lead maxiballs or Ballets. If it is one in 48 you can shoot a lot of the conicals which are legal as well as the Powerbelts. If it is a .50 cal I think a 348gr. Powerbelt would do well out of the rifle. I have an Omega which I use for elk in Arizona; however, I have killed elk with .50cal. T/C scout which is less of a rifle than your Hawken. If you must go with a new rifle and think an inline type might be more what you are looking for I guess the best I can suggest for the money is one of the H&R break action ones that are still USA manufactured. There are a couple of other similar rifles made in USA as well as some made in Spain which many feel are not as safe shooting heavy loads with as the USA manufactured ones. As far as easier cleaning you could try one of the new synthetic powders that leave little residue and are not as corrosive as the old stuff. I recommend in the following order from best to worst best is Black Mag'3, the next best is American Pioneer Powder if fffg form, Next best is probably Goex Pinnacle in fffg (although it is so new I have some but have not shot it yet), next is Tripple Seven in fffg form (personally I do not like the triple seven but a lot of guys have good luck with it even though it tends to form a crud ring in the barrel which makes quick reloads more difficult). With the Black Mag'3 or American Pioneer in fffg you will probably be able to reload and shoot a second shot without a swab between shots. I would set the rifle up with a peep sight although there seems to be a lot of question as to whether peep sights are legal in Colorado. I have seen a lot of posts that say the residents use them and the game wardens do not complain. If you are old enough for your eye sight to be like mine (at 67) the peep sight is the only open or iron type I can use and get a good sight picture anymore.