06 is more than enough...knwo your distances...have a range finder good out to 400 yards on deer sized game...and print up a little sticker that you can mount on your scope to tell you drop for distances...will help your son remember and remind you in heat of moments...is a simple little trick, but works VERY well for younger/inexperienced distance shooters...

as to how far...Would HIGHLY recommend practice practice practice for distances out to 400 yards...and then discipline yrouself to get under 200...but 75 would be a very short shot for open country...

I hunted elk with a guy on my first elk hunt and he dropped an elk with a .243. Not that anyone would recommend it but it goes to show what a well placed shot will do for ya. Good luck on your hunt!!

i have a 243.. best gun i ever owned.. just make a good shot she'll kill anything

good info guys. its such a nice rifle too--win mod 70classic compact, w leopold 3x9 vxII-- certainly a pleasure to shoot, carry, etc. vs some of my bigger guns.thanks.