Semi auto and velocity spread

Hello,
Need some info and thoughts.
I have a BAR in 30-06 - running 52.5 grns IMR 4350 with CCI primmers and 180 grn Sierra Gamekings for Elk this fall.
Shooting around 3/4 for 3 shots at 100 yds off sand bags, 6 shots opened up to 1 1/2" at 100 yds.
I shot thru my cronograph to get muzzle velocity and I then can use the tables for my cheat sheet/notes.
This load is averaging 2490 to 2618 fps, with the 8 rounds I shot.
I am surprised it shoots as good as it does, with this spread.
In the past, any bolt gun with this much spread, would shoot terrible.
Do semi autos, in general, have more of a velocity spread due to the gas working the action?
Or, is my load what my BAR wants, but just not consistant with the velocity?
No pressure signs, brass issues or anything, just want to know what some others think.
Thanks in advance.

I think your Chrony is lying to you. lol

The gas system will change the SD from what it would show up in a locked breech system but i have to agree with Yobuck and say try another chrony.

Heck with those groups from a BAR I would split the difference and plot my trajectory from that. Those 3/4" groups are impressive.