Lapua 260 brass.

[KevinThomas]

Charlie Pappa,

Hard to say without actually seeing the brass. I'd assume that the pressure issues are most likely caused by neck clearance or possibly doughnut issues. Unfortunately, as L.E Wilson used to say, "you don't know what you think, you only know what you measure." Withour actual measurments, this is strictly a guess on my part. I'd say you'd need to confirm the dimensions in these areas and compare them to what you have in your chamber. Might want to start with a chamber cast, and go from there.

 

[Mark S in NM]

I just received new Lapua 260 brass, measured H2o capacity 54.1 grains which is exactly the same as my necked down 308 Lapua. Loaded with Berger 140 miked .294".

 

[Charlie Papa]

Charlie Pappa,

Hard to say without actually seeing the brass. I'd assume that the pressure issues are most likely caused by neck clearance or possibly doughnut issues. Unfortunately, as L.E Wilson used to say, "you don't know what you think, you only know what you measure." Withour actual measurments, this is strictly a guess on my part. I'd say you'd need to confirm the dimensions in these areas and compare them to what you have in your chamber. Might want to start with a chamber cast, and go from there.

I measured fired brass at the neck and came up with .298" being the average. Loaded necked-down 308 Lapua are measuring .293-.294" and the necks are turned all the way to the shoulder, and the shoulder cut slightly as per the Sinclair hand-turning tool's instructions. From everything I've read, that should give enough clearance, but I could be wrong. Remington brass gave better results, but I didn't have enough time to test but two loads. Haven't developed anything yet on it.

Is there a .260 load that is somewhat universal, like 44-45gr of Varget and 175 SMKs in .308? Something that shoots pretty well in almost any rifle? I could try something like that in both kinds of brass...

Thanks!

 

[memilanuk]

From when I shot a 6.5-08 for XTC briefly... 139 Scenar or S142MK 0.020" off lands, 38gn Varget, or ~42-43gn H4350. The Varget load may not be the zippiest one around, but it gets them to the target and puts them in the center time and again. The H4350 load got noticeably better velocity (low 2900s vs. mid-to-high 2700s from a 30" barrel) but the Varget load was the darling of the crowd I was learning from at the time... still is for some of them. Works in gun after gun after gun...