I think Mac has many good points, but must admit that I have found Handi 243's to indeed be a crap shoot. I've given up on two 243 Ultras, neither of which would not settle down and group. Now, before i get accused of not having any "Handi Sense" again, let me assure you I am not new to H&R/N.E.F. single shots. For me, some calibers are just not worth MY time to continue to tinker/cobble with. But it is obvious that others have had good results with 243s. To some shooters, the needed tinkering is a challenge, part of the fun factor. To each his own. I have had excellent results from my 30-30s, 45-70s and 25-06.
Wally