UncleNorby

Ah yes, the old Jam-O-Matic.

First thing I would do is familiarize yourself with the inner workings of this gun, and the proper cleaning methods. I would then clean it thoroughly and take it to the range and shoot hunting loads, not military .308 stuff, to make sure it functions reliably. Hopefully it works just fine.

Then, as others have said, if it shoots well with 150 core-lokt or similar bullets, those are fine for deer and antelope. You could step up to premium bullets if you want, but they aren't necessary to kill this size game. I would use 165 or 180 gr loads for bigger game and again, premium stuff is not required.

Teach Deer

Best all around load (pronghorn through elk) would be a 165 gr bullet with controlled expansion (e.g. Nosler partition)...

Better choices would be...

Pronghorn-whitetail / mule deer at long range 150 grain Ballistic tip / Ballistic Silvertip
Whitetail / Mule deer up close 165-180 grain Core-lokt / Fusion / Silvertip
Elk 180 grain Nosler Partition / Interbond / A frame...check out Hornady's Light Magnum loads

I love the 742 and with proper cleaning have never had any problems with factory ammo...they have jammed with handloads before though...and they do NOT cycle Managed Recoil loads (if your curious).