Sierra 6.5 142 MK

[jesilva]

I have been using the 142 MK in my 260. Purchased 500 about 6 months ago and just ran out. Purchased two hundred more two weeks ago. The first batch measured 1.359 base to ogive using a sinclair's comparator and the new batch measured 1.376 base to ogive. It appears that I now have to work up the loads again because of the difference. What guarantee will I have that the next batch will be different than these. Anyone else notice this problem with their Sierra's.

Jim

 

[brian427cobra]

Seat all your bullets by ojive length and it won't matter which batch they came from, this has worked well in my 260 with 139 Scenars.

 

[jesilva]

In essence you are saying that the difference in the amount of bullet in the case is negligible.

Jim

 

[brian427cobra]

Good question, I'm not a BR shooter, but each bullet should be seated by ojive length, so they all have the same jump\touch\jam to the lands

 

[mikecr]

17thou more in the case will be pretty hard to see on paper