I've done it for years. Used a side lock traditional decades ago. Went to inline modern about ten years ago.
Cleaning and lube is critical. After cleaning most people oil the bore. This oil can accumulate and make for spotty ignition, especially with the traditional side lock and #11 caps. Its not so big a deal with inline and 209 ignition, but it doesn't hurt to be careful. If you want 100% no issues, then clean, lube and store the rifle muzzle DOWN. Lubes will slowly migrate to the muzzle, instead of collecting in the breech. No more ignition issues.
Test fire with a cap or two before loading.
I use Hodgdon Triple 7 Pellets and pure lead bullets inside sabots (Dead Center). It helps, dramatically, to spit patch between shots. My guns shoots more accurately with a simple spit patch between shots. I've been using a Tompson Center Contender Carbine in .45x209. While the rifle will take 150grains of powder, two 50 grain pellets are plenty. Think about it: The 45-70 was considered an absolute hammer on deer and buffalo. Most modern inlines shoot 45 caliber bullets inside 50 cal sabots, all over 100 grains to 150 grains of powder. In other words, the modern inline .50 is shooting a 45-100 or 45-150 load...... A 45-100 works great, a 45-150 isn't necessary.
I tend to hunt in all weather. Some inlines had an exposed cap. I didnt much like that. I bought the Contender because the cap was totally sealed within the breech, away from rain wind and snow. Now there are more inlines with similar enclosed breech systems, either opening like a single shot shotgun, or using a falling block action of some sort. I strongly recommend something with an enclosed breech.
My 235 grain soft lead bullets will typically completely pass through broad side deer. I did collect my first bullet on a transverse shot this past fall. It stopped under the hide on the off side. All have been one shot kills,
I use a Weaver grand slam 1.5-5x scope. Plenty for the typical 50-100 yards I usually use this rifle at. Accuracy wise I cnz get about 2-3" groups without trouble, which is minute of deer without an issue at these ranges.
Seriously ignore the max charges. Load for accuracy. 75-100 grains of powder will kill deer cleanly if you use good bullets. Pistol bullets seated in sabots don't fly all that great, and terminal performance is merely okay. I recommend something more streamlined, and using a soft lead bullet in a sabot.
Tactics are same as hunting deer with a modern rifle. Deer steps out into field, you decide to take it, hammer back, sight and squeeze. Get out your gutting knife. In the woods hunting a trail, the only difference is the hammer on the Contender. If the Deer is close, I don't just hammer back. It will "click". Instead, I pull the trigger, ease hammer all the way back, then ease the trigger out so I can cock it without an audible click. Then again, I've done that with nearly all hammer guns including win 94 30-30's... tactics are identical to any other deer season
the only other thing specific to BP is ammo management. I carry three ammo "tubes" each with two 50 gr pellets, and one bullet/sabot. Also carry a gummy plastic cap holder thingie that holds a half dozen caps. Caps are easily lost. You will lose one or two. I attach a small flannel patch to each tube with a rubber band. To reload after a shot, I moisten the patch with saliva, run the patch down and back to remove some crud, then drop in the pellets and load the bullet. Done.