I've been loading them for a long time, as well. There are things to be aware of. If you are using H110/296 or the new Alliant Power-pro 300MP, these slow spherical powders require good start pressure and are probably most easily left to a jacketed bullet with a very firm crimp applied. You can use them with very hard cast bullets, like the Beartooth Bullets products, but because of the need for high start pressure, you want to use even those bullets at the heavy end of the weight range with them. Other powders, like 2400, are more forgiving and will still get you into the magnum range and are a better choices for warm lead bullet loads.
Gary's suggestion to slug the barrel is a good one for two reasons. One is an exact determination of the groove diameter of your bore, as your lead bullets should be one to two thousandths over that diameter for best accuracy. The other is a chance to feel the condition of the bore with your cleaning rod. You are feeling for constrictions, particularly under a dovetail cut in the barrel for sights or for front stock anchoring. Those have to be lapped out for best lead bullet accuracy and to minimize leading. I always run a pure lead slug from the muzzle and then another from the breech end. If the bore has any taper, they can feel quite different. If you need to lap, either firelapping or, if you know how, hand lapping will address it. Just be aware you will have to slug again to check the final diameter you arrive at to choose the right bullet diameters. Going to coated bullets or gas-checked bullets or plated bullets will all work if your bore is in good condition.