Quote Originally Posted by Zero333 View Post
Difference is because...

It's a new barrel still being "seasoned".

Bore conditions can have a affect on MV's.

After you shoot 100 to 200 rounds things will get better.

Another thing you're forgetting is that top notch factory Match ammo can vary 30+ fps in velocity.

I assume Hornady is using H-4350 or similar temp stable powder so the outside temp would have to be very different to vary 40 fps.

One has to shoot a minimum of a 10 shot string to get a true average muzzle velocity with honest ES & SD figures.

Too many times I have chronoed a 5 shot string that had 5 fps or less ES, but when I shot a 10 shot string with that same ammo the ES was 15 to 20 fps. And these are my handloads.

The best ES and SD I have chronoed from factory ammo was 31 fps ES from a 10 shot string.
Good to know, I'll try a 10 shot reading next, thanks.