Got to the range this morning ahead of the next few days nastiness. Winds from the 2 o'clock and gusty from 14-18 or a bit more....the flags never stopped moving. Loaded the Lapua cases with WW760 and a Nosler 70 BTip @ .010 off the lands. While not always the ultimate powder in the 243W's, over the years 760 has proven to be a solid performer in any 243W that's got anything to show me. Could have cheated and plopped some of my BR bullets in there
but the Nosler 70 BTips have always shown me good accuracy and are pretty forgiving in any factory barrel I've tried them in. Primers were Fed. standard 210's.
Bore sighted at 100 and with the w/e adjustments centered, the first shot from a clean barrel was 2" high and 1" right....another plus for properly aligned/bedded bases and rings.
Fired four more to put a bit of temp in the barrel and then got right to the "...rat killin' ", as The Duke would say. Groups were three shots and no extra time was allowed between shots for cooling of the sporter barrel...when the flags said "Shoot!", I shot.
Over 3 grs. of powder changes, the average group size of seven 3 shot groups was .425 with the largest being the single .664 and two small ones of .395 and .360. Four of the seven groups measured .502, .515, .536 and .523. Pretty solid consistency for a sporter barrel hunting rifle. There's a hint of vertical in all the groups but you can see it come out as the powder charge increases...a sign of good bedding and a decent barrel. A slightly faster powder like Re15 or N135 and/or a bit of juggling with seating depth will bring that around.
Next trip out, I'll evaluate some 90 gr. Partitions as it's main purpose is a combination deer/antelope rig that can double as a solid coyote whacker with the same load and zero.
Good shootin' -Al