Largest caliber-50-140-700

Most powerful- my .458 Lott

Most recoil- I grew up hunting with an H&R Topper 12 ga. with 3" chamber. It weighed 5.5 lbs. With a 3" magnum shell it was pretty harsh, faster and heavier than my Lott.

Most powerful handgun- That's a toss-up between a .375JDJ, and my .475 Linebaugh, but the .475 has it beat hands down in the recoil department, and I would prefer it for killing power over the .375 JDJ. On paper the .375 might have more FP of energy, but that isn't what kills.