Slugs............I also like the properties of a big round ball. Besides, lots of history there. Jimbo is right, they do bleed off velocity pretty rapidly, and a Foster slug does a little better in that dept. but the Foster is light for caliber, and soft. Not quite at the "spread on toast" density, but close. Even a 20 ga Foster is fine for deer at 75 yards or so, but a lightly hardened 14 ga RB is a lot harder to stop.
In his great book written 150 years ago, Lt John Forsythe opined that the round ball was the ultimate hunting projectile. His book is very convincing. His theory: use a shallow twist light rifling. Easy to clean, lots of speed. A RB needs little twist anyway, and the bigger the ball, the less twist needed: one turn in 12 feet being about right for an 8 bore. His main caveat was make sure it was big enough. His favorite allround was a 14 bore: 69 caliber: diam .678 considering patching material. 478 grains roughly depending upon composition. 225 grains of 2F giving over 4000 ft lbs of energy. He shot a lot of buffalo with this gun.
Time has proven the Lt wrong, and my 45 Hawkin will deliver more energy than my .62 roundballer...at distances beyond 150 yards.............but I cant shoot that far anyway.
The company, "October Country" makes a replica of Forsythe's guns. The model I like best is called, "The Liver eatin Johnson". But a friend of mine has produced over 7000 ft lbs of muzzle whop with their biggest gun.
In the museum at Kimberly, a half century ago, was a 4 bore, made by Rawbone of Cape Town. Who says a roundball can't kill elephant?
FWB