7mm 140 gr accubond/BT bullet load difference??

[ajstew32]

I finally found a load that will shot good in my 7mm STW. It is over book max at 80 gr of IMR 7828 with 140 gr accubonds, the groups tightened up nicely to 1/4 inch. since i can't find any anymore accubonds and only have 20 left i thought i would just shoot the BT for paper punching since the BC and SD are the same and the same design(as far as i know). but the same load put a group just over 1". is this normal or what do you thing is happening?

 

[Lefty7mmstw]

In my stw I shoot the bt and the ab interchangeably, but you should try them both side by side in your rifle to be sure yours does well.
I at one time shot 80 gr 7828 in my sendero 7stw with a 140, but when I put a strain gauge on my rifle I found out that 78 was already on the edge for peak pressure. I switched to 81 rl25 and I fell below 60,000 psi with the same speed as 78 7828 with a 140.

 

[ajstew32]

Ok thanks for the reply. I maybe should drop the powder down a little. I just go by primer for max. And when I got to 80 I just said it was high enough and didn't want to push my rifle to hard. Tried out the 160 gr accubonds and they look a little better and I can find more.