I have just started to work up loads for a new 308win, and I have noticed that there is not very much neck tenson with the 180gr sierra sp. In order to try to find out the problem I measured the expander ball on my redding dies and they were .306 which seems right. I measured the bullets and they measured barely .307, which seems wrong. The brass is new fed gold medal, which has been full lengh resized.
Can any one help me with the this problem cause I have never had this problem in the years of reloading.
Thanks in advance for the help. And how much neck tenson should you have.

You should be OK with the measurements you have although there is definitely something wrong on your measurement of the bullets. They should be be .308". Are you measuring with good measuring equipment?

Proper "grip" on a bullet is about .002". If there is disparity, it could be undersized bullets, which I doubt, or neck wall thickness in your brass. Measure your necks after sizing and before seating a bullet. Then seat a bullet and measure. The difference will be your "grip". Except for single loading at the range, .001" grip will be too light. Bullets can be driven back into the case on recoil with that measurement. .002" works well for good accuracy and bullet retention in all but the light, heavy recoilers. On the latter you might require .003", or crimping to insure retention upon recoil in the heavy kickers.

I am measuring with good calipers, and I even measured about 20 bullets and they were all about .307.

Thanks for the input ill try to measure the necks also.

Today I looked into the problem even more and here is what I found. My case necks measured .306 which I think is right. I started to measure the bullets and they are interesting. At the base they measure .308. About 1/8in down the bullet they measured .307. And about 1/4in down the bullet they measured .3065. These are 180gr sp which are long bullets and they should be .308 for much longer than are.

Has any one ever had this problem with these bullets.

Call, or email the manufacurer,and get it from the horse. That way if you have any other questions, they can answer them directly....

Scout....