I came across a recent poll and the subsequent chatter on the A.H. forum about which calibres would be best for leopard. It's a pertinent question, however in my opinion, it is easily answered. Craig Boddington said it best, and I will paraphrase the outdoor writer here. Any adequate deer calibre is going to kill a leopard. But what I think Col. Boddington (or is it General now?) also implied here, is to use a deer calibre in a weapon that you have continuously hunted with in the past and are hence very familiar with. I think that's the important part of the message, especially from a practicing PH's point of view. It is quite concerning when a client steps up to the range on the first day of the safari with some brand spanking new weapon that's only had a handful of cartridges through it. I know it's unlikely the fellow is familiar with the thing and it's peculiarities. When a client brings 'old faithful' that has been in the family a while and has been consistently putting meat in the freezer, I always have a smile on my face. Chances are he/she is proficient with it.So what is a good leopard calibre, technically? Anything from a .270 on up into the .30's is going to do the trick with aplomb. I know of a young lady client who dropped a big Tom in its tracks with .243. She learnt to shoot with that weapon as a kid (familiarity!) and was coached on exactly where to place that bullet to ensure a clean kill. Just bear in mind if you are going to use a large calibre you are going to waste a lot of kinetic energy as that bullet is going to whistle on through, and you are subjecting yourself to increased recoil which is going to affect your ability to accurately place that shot. Why not let the bullet do its job and expend the majority of that energy inside the cat? Don't get me wrong, an exit wound would be nice - especially when having to do the subsequent follow up- but I want the bullet to do the majority of its work inside the cat rather than accelerating over the horizon. The legal calibre for leopard in Zim is 7mm and 3 kilojoules of energy at the muzzle as well as rifled barrel of no less than 500mm.
I think an important factor to also consider, is the quality of glass on your weapon. Get the best you can afford. An illuminated reticle works wonders too! Invariably that spotty comes as the light fades and you often struggle to pick up fine crosshairs against that feline form in the half light.
However there's something else we need to consider. Your leopard calibre of choice will invariably be needed to procure your bait and your selection of plains game species. So you are going to need something that's going to take Mr. Spots at 50 yards as well as that wildebeest bull out at 200 yards (and everything in between). That's a variation in body weights from 120lb for a leopard, up to 600lbs for the larger plains game species and up to 1800lbs for Eland. In my opinion, you are far better served by using a .300, a .338 or even a .375 for Eland. Just bear that in mind when you plan your calibre selection for your safari.
In conjunction with choosing your calibre, is your choice of bullet. Some like bullets that expand quicker - I guess this would be fine if leopard and small plains game are on the menu, but bear in mind safaris are often a mixed bag requiring a calibre to do double duty on cats and the variety of plains game. My choice would be one bullet type and weight (heavy for calibre and one that doesn't mushroom too quickly).