I'm in the process of working up loads for my Sako sporter 6 PPC and have tried two powders (H322 and VV 133) and two bullets (Bart's and Watson 68-gr.) now, and have varied seating depth and powder-charge weight in my quest for best accuracy. With all these factors being varied, there are a lot of variables--and resulting combinations--at work in the process. I'm loathe to add still another variable--neck tension--but am wondering whether perhaps I should. All of my loads so far (with by now about 150 rounds down the tube) have been with .002" neck tension (if that's how we measure it)--by which I mean I have sized the necks down (with a Wilson chamber-type neck-sizer) to .002" less than the OD of the loaded rounds' necks. More specifically, I've used the .260" bushing for the OD of loaded necks of .262".
So here's my question. Can I realistically expect any change in performance (group size) by trying some loads with .003" neck tension--i.e., using the .259" bushing for the OD of loaded necks of .262"? Adding still another variable into the process adds to the complexity of the load-development process, but if there's some chance that different results may be expected by varying neck tension, I guess I should try this. I've read that certain powders work better with greater neck tension than do some other powders. Is there enough here to try this, or am I likely to see no change in performance?
So here's my question. Can I realistically expect any change in performance (group size) by trying some loads with .003" neck tension--i.e., using the .259" bushing for the OD of loaded necks of .262"? Adding still another variable into the process adds to the complexity of the load-development process, but if there's some chance that different results may be expected by varying neck tension, I guess I should try this. I've read that certain powders work better with greater neck tension than do some other powders. Is there enough here to try this, or am I likely to see no change in performance?