I have a friend at work that is just starting to get into hunting, and he is looking for his first rifle. We live in southern Kansas and he knows that he wants to hunt deer. At this time he is unsure if he wants to hunt elk or antelope. Mimimum caliber for deer is .24 and .26 for elk. He is not sure how long it will be before he buys a second gun, if at all. Knowing these facts, I have been trying to steer him toward a 7mm rem mag. I have also mentioned that a 270 and 30-06 are also acceptable for Kansas game. I do not want him to get gun that shootshard to find ammunition. Is my suggestion correct or should i try to steer him a different way?

Welcome!
I think you are on the right track with suggesting either a .30-06 or a .270, but if he wants to go after big gamehe ought to get the 06 for the better bullet suggestions.
Borty

i think a 270 would be on the right track. it would be my pick.

You can't go wrong with any of these:

.270 Winchester
.280 Remington
7mm-08 Remington
.308 Winchester
.30-06 Springfield

I think that the .30-06 is the best all around cartridge, but its easier to find CHEAP ammo with the .308 to practice with. You could really throw a dart at these rifles and be fine with whichever one you came up with.

For a "one gun does everything" scenariothe 06 is probably the ticket. If he is going to get more than one gun I would start with a 270 WSM for a super flat shooting deer antelope gun, and pick a big game rifle later in 30 or 338 caliber.

For a first gun the 7mm-08 is a great choice for deer and elk at shorter ranges.If he handles recoil well the 7mmremmag is a fine choice and is better for elk and moose at longer ranges.

270 would be my choice followed by the 7mm-08. If recoil is not a big issue then the 30-06 would last him for life.

30-06!

With all the open ended variable and uncertainties, definitely the 30-06 and he'll be set for life to go most places and do most things from prairie dogs to moose and elk.

Ammo is cheap and plentiful, plus the variety of bullet weights and power loadings is outstanding:
** "Managed recoil" for plinking
** "Regular" for deer
** Federal "High Energy" for more serious game.

Very versatile and very much NON-specialized, that is its strength!

I can't believe we are STILL arguing this one after decades of the same thing: 270 or 30/06???

If you don't want both then why not just split the difference? How about a .280???

Course if you have a .280 you need neither of the other two!
RA

Didn't see much "argument" in there.
Besides the guy will most likely buy the whatever the last salesman talks him into anyway.
Maybe a 300 RUM