I messed with a Remington 788 in 243 back in the 1970's - shortened and slimmed the stock, glass bedded, shortened barrel to 18 1/2". Built it to fit my wife. After several hundred practice rounds over the summer, she took her mule deer, shooting off hand, with a single shot at about 125 yards. Several years later our 13 year old son took his first white tail with it - probably less than 100 yards, but through a tree line - we saw it jump once or twice and pile up after his shot. Both were broad side standing shots with bullet impact nicely behind the shoulder. 85 grain Speer Flat base - no longer listed, I see. Everyone using 308 Winchester with 165 grain, now-a-days. Just getting a 783 Compact in 243 set up for our grandson - will start with mild loads using 55 grain Nosler Ballistic Tips on hand for targets, gophers and the coyotes at his other Grandpa's farm; then move to 85 to 95 grain Partition / Accubond for this fall's deer hunting. My thoughts are that 243 might be borderline for big prairie deer and up, but shooter being confident of when able to hit a 6" target (small paper plates) and when not, makes a huge difference.