Hello all.
 I bought a Bushmaster Varminter about 4 months ago.I went to a large gun show and purchased about 8 different loads to see what my rifle likes best.The tightest group has been with Winchester 45 grain hollow point.My second best load has been the Federal XM193 55 grain.Most of the other loads were various 55 and 62 grain.I am wondering if i should concentrate on the lighter loads like 45 grain or try going the other way and try heavier than 62.I only use it for shooting paper but would like to find "THE" load for when i can find someone in NJ to take me varmint hunting.Thanks in advance for any replies.
  BTW.My targer practice has been with a BSA 8-32 scope with harris bipod or with sandbag.

The rate of twist in the barrel is often the determining factor in deciding the best bullet weight to try, many barrels these days are marked with the rate of twist, that gives you a place to start.  More answers to your questions can be found at:

[url]http://www.ammo-oracle.com/[/url]

twist rate is not going to be an issue with you, the varminter has a 1/9 twist rate which will be fine for handling anything up to 69 grains.  there is no reason to push that limit if you are just using it for target practice and small varmints.  in general the heavier loads will retain their velocity more for longer ranges.  55gr M193 should do what you are looking for just fine.