I've never gone antelope hunting but I always thought a Remington 700 mnt rifle in .260 or .280 would be a good choice. I'd go with a good 3x9 scope.

I was able to go after pronghorn in 1991 and have taken only 9 since then, along with 10 mule deer. The .270Win with 130gr Hornady bullets has never failed to drop pronghorns or muleys on the first shot. Now, I have to admit, I am close, when I shoot, usually from 200 to 300 yds. The longest shot that I have made on pronghorns was a 325 yd shot. Hit a tad high over the heart, but he dropped without taking a step.
.270Win has been around since 1935, so the cartridge is not new or sexy, but it simply keeps on performing, year after year....AND you can buy ammo in any little country store or gas station that carries ammo.

25-06 is what I used to take my "goat"...

I took one in CO with an 06', but I have repeatedly read the classic lope' gun is a M70 Win (The Rifleman's Rifle) in 270 win. Of course, any other rifle would do just as well.

Short actions - 243,6mm,250savage,257roberts, 260 rem, 7mm-08, long action - 25-06,264win,270, 280,284, all 7mm mags. There are TONS more, flat trajectory is the key.

I don't think you can go wrong with the 270-Winchester. I still use my 270 about 50% of the time. The rest of the time I use my 7mm-STW. The 7mm-STW is a great round, if you handload for it.

You can't go wrong with the 25-06 Rem great gun for lopes to coyotes,to deer.I shoot 100 gr Barnes-x and that works good,or the 115 gr Hornady.

If I had a choice of guns in the 25-06 I would choose the Winchester Classic Sporter LT.
Choice of scope would be the 2.5-10x40 mm Scheeles outfitter scope.

well you can get a new 257 wby mag and top it with a 3.5-10 luapy or you could buy a Zeiss Conquest 1" scope with a 3-12x56 and put it on your 243......either way you go you will be happy. me i would put the zeiss on the 243 and use 95 barnes x bullets or 100 grain noslers

lapdog, these guys are right on with the .25-06 or .260. The .243 is Ok but I watched more than one antelope take an 80 gr .243 in the chest and take off to another county. Oh, it killed him but not real quick. I really like the .243 and killed alot of deer with one but I wouldn't use anything less than 100 gr bullets.
I think the .25-06 would be a fantastic choice as would the .260 or .257 Roberts. Get one of these and you will never have to buy another rifle again as you got one to take just about anything that walks (yeah right).
My favorite all round cartridge for deer and antelope is the .270. It shoots plenty flat enough and packs enough punch.
As for scope, your Leupolds are good. If you like em, stick with em. I would get the ballistic plex though. I like the one on my Burris fullfield II.
As for rifles, sthick with what your most comfortable with and fit you. You might want to try out one of the new Savage rifles with the accutrigger. These are pretty neat.
My friend got one an few months ago and we can't in .30-06 and it shoots everything good, and really likes Sierra 180 gr boattails.