velocity drop in 300 wsm

[born to hunt]

Check me on this:

Loading a 168 Barnes TTSX and getting just under 3200 fps with .75 - 1.0 MOA...which is great for me. I upped the charge by a .5 grain and noticed a velocity DROP by 100 fps with inconsistent chronograph readings. Groups were about same. Using RL22, 71 grains, compressed. Rifle is Tikka T3 stainless with max seating depth based on box magazine constraints.

Theories
1) I've hit max load and should dial back
2) my chronograph is screwed up
3) ??

Looking for help. I have not had time to go back to the lesser load and reaffirm the initial chrono readings.

 

[steve4102]

Number 1 and number 2 are very possible. I would lean more towards #1 and test your "hot" load against your other loads in the same chrony session.

 

[steveno]

#1 is my guess

 

[GJgo]

TSX & TTSX need to be at least .050" off the lands for good, consistent results. Consider that along with your magazine depth limitations.

Make sure it still groups well at 200 & 300 yds before you go hunting. Worth checking.