Late in life, I "discovered" the .243 Win as an eastern coyote cartridge and have been pleasantly surprised by its effectiveness on deer.
Last year, I took my Tikka T3 Lite when carrying my portable blind uphill to a good spot for my son-in-law to hunt in the rain the next day. When setting up, I was surprised to see a 140 lb. spikehorn standing in the old snowmobile trail, 190 yards away. One shot anchored the buck where it stood.
I use 80 grain Hornady GMX solid gilding-metal HPs for that and all other cartridges we use for deer in Maine. For Florida deer, 100 grain factory loads should be fantastic.