Dangerous?? Don't overload it. NEVER even THINK of using smokeless. I find no need to load more'n 90 grains of anything and I shoot 70 grains of 777 Pistol in my CVA Wolf which is rated for 150 grains of Black. It shoots a 385 grain Hornady Great Plains at 1800 fps. I think that's adequate.
I don't know what my Investarms produced Cabela's Hawken Hunter Carbine is rated for, but I load it with 90 grains (all these weights are not WEIGHTS, but are black powder volume equivalents) of Pyrodex RS behind the same projectile. It's got a 1:24 twist, the Wolf has a 1:32 twist, very tight for conicals and sabots. I've got a conversion on the Hawken to allow a 209 primer ignition. The Wolf is 209 primed being an inline. Shooting any substitute to BP in a sidelock can give iffy ignition, thus I just did away with the percussion caps. That 209 adapter on the Hawken sidelock will even reliably fire Buckhorn 209 sub which is notoriously iffy. It won't even fire in my Wolf, but CVA does make a BH209 breech plug which has a larger diameter hole for the primer to fire though and allows shooting BH209. BH209 is non-corrosive and that's the big attraction to me, plus I don't have to scrub the bore every shot or two to maintain accuracy when shooting paper. BH209 is expensive. I stick with 777 in the inline because I like the power of the stuff.
I've yet to chronograph the BH209 in my Hawken. I've heard it's pretty powerful, too. Main thing, the stuff is ACCURATE in that rifle.
If you go to the BP forum with this question, you'll get all sorts of descention about using any subs, the "holy black" crowd. ME, though, I'm about shooting and hunting in a modern world. I really don't care what Davy or Daniel or even Jim Bridger used. I figure if they'd had inlines and BH209, they probably would have used THAT, let alone if they'd had .30-06s.
I cannot just go to a gun shop and buy black powder. If I could, I might keep some around, but it doesn't exist at gun shops, too much government required BS involved for the amount of sales they'd get. You have to order it and then you pay a hasmat fee, might as well up the extra cost of BH209, works better anyway once your gun is set up for it. Of course, if you have a flinter or "rock ignition", you'll be forced to shoot BP. Good luck on that.