I've started load developement for my 270-300ultra. I broke in the barrel just as advised by Lilja, after about the tenth or twelth shot there has been no copper fouling worth mentioning. Three wet patches of BBS and a couple dry and it's clean. I've never had a barrel clean so easily. I've been shooting five shot groups and the best so far has been right at an inch @100. Velocities have been pretty high (135MK @3800 w/102gr and 150 Ballistic tip @3400 w/96gr), but inconsistant, as much as 75fps between highest and lowest shot. I figured that when I fix the velocity problem the groups will tighten up. All brass used was weighed sorted to be within 270-271.9 grains. Norma 404jeff showed same inconsistant velocities as Rem 300RUM brass. All were sized down and trimmed to 2.840" then necks turned to .011" per side with a few @.0105" just to see if there was any difference. With bullets seated necks were @.299" and .298" for .300" chamber neck. Note No sizing required to reload fired brass. Federal 215 primers were used to light off the WC872. Sierra 135gr matchking seated to touch the lands. With the MK out to touch the lands only about half the neck is in contact with the bullet, thinking maybe bullet pull is inconsistant? Any help would be greatly appreciated.