What caliber do you guys recommend for Antelope, I am thinking 243 or 25-06??

Either of those choices would be excellent, along with many others, such as the .270, .280 , 7mm-08, 7mm Rem mag., etc...

Any flat shooting cartridge capable of 300-350 yard shots will work fine...

As a dedicated pronghorn rifle, the 25-06 with 100 grain bullets would be pretty tough to beat...

264 win mag is hard to beat

I would say a .20-06. My uncle's friend in Nebraska uses a .25-06 on his antelope, and he loves it.

I recently bought a Ruger 25-06 mostly for antelope and the occaisional yote or fox, maybe deer. I'm topping it with a Nikon Monarch 4-12x40. I've got a 30-06 for the bigger critters. After lots of reading and good input from this board, I think the 25-06 is the way to go for lopes. Guess I'll find out.

Like ShatoDavis said, the 264 was designed for long shots at Pronghorns. This caliber really never made it big. It was harder on barrels that standard 7MM Rem Mag loads which at the time was its biggest competition. I see that Remington is now chambering it in one of their new rifles.

Depends on how far you're shooting. The 7mm Rem Mag is my all-in-one round. It'll reach out and poke stuff from a long ways away with plenty of knockdown power.

7mm STW, or RUM. Good luck.

.270wsm is very hard to beat. But I to like the .264wm, it is a great round.

I shoot a25-06 withwinchester 120 gr positive expanding points and have had great luck on lopers and deer. What guns you may already own would probably do fine too?