I am trying to fegure out something I was shooting my .257 ackley
over my chrony friday and was confused about my SD readings
I thought that when you got low SD that the groups should be tighter
am I wrong :?
Yep..... The SD of your load isn`t a guarentee of a good load, it just means all your bullets are traveling close to the same speed. The SD means more at long range where the drop of the bullet comes in play.
The ideal is a accurate load with a good low SD but for rangs under say 4-500 yds I don`t think it matters much. I`ve found in my rifles some loads group very tight with SDs of 7-80fps and lousy with SDs under 15-20 fps. I always try playing with seating depth and at times will rework the load with a different bullet of the same wgt & style to see if accuracy improves, but this usually just causes the SD to change and the accuracy seems to stay the same.
IMO, I think the best way to look at it is a good load is a good load under 300 yards no matter the SD as long as it`s with in reason. A long range load needs a low SD but you`ll likely have to hunt for a accurate load or three and sort them for one with a lower SD.
