High powered is not better IMHO, neither is a large objective. If you are hunting and a buck pops out at 50 yards, a 6-24 is not going to make it easy to pick up the buck. Quality glass will out perform cheaper and big. A VG quality 2-7 or
3-9 either 32, 38 or 40mm objective will easily take game out to 400 yards. A strait 4x scope will make shots out to 300 yards fairly easy. Another point to remember is the 740 is called the Woodmaster. It is accurate for hunting purposes that really don't exceed 200 yards. It has never had a reputation as a long range platform, just to many moving parts for accuracy sake. If you have one that shoots 3" groups at 100 yards, off bags, at a range, your about average.
Try it off hand and your groups will get much larger. It was designed as a woodland hunter made for quick follow up shots.
Weaver makes a 2.5-7x32mm that would be perfect, the Leupold VXII 2-7x33mm would be an awesome choice also. Best of luck.