I bought a couple of boxes of calhoon 55gr hollow point round tails several years ago at a local gunshow east central alberta and was very happy with them. Great accuracy, good expansion, on coyotes out to 350 yds. but since then i haven't found any more. just wondering if anyone know any thing about them. according to the box they were manufactered in Calgary Alberta. now I've been using 52 Speer HPBT match or Hornady 50gr V-max(as for the weight difference 2grs doesn't seem to matter much) over 39.5 gr of WW760 or Ammo mart 47SL I get aprox 3400 fps plenty for a point blank range of 360 yards on a 6 inch target but without the concern of throat erosion.and I get a sub MOA 10 shot group, in fact i got bored shooting the same hole while test firing this load. I generally work up a load for accuracy before i ever chrono them. there's more to loading than velocity.