New chronograph question

[Oldschool280]

I finally assembled and used my caldwell chronograph yesterday. I had it set 15 feet from the muzzle. First shot out of a cold barrel was 2701, rest of the shot (5) were all at 2615 plus or minus 5 fps. Is it normal for an ice cold barrel to produce a faster moving projectile. Or was it just something else lime case differences and such. I have not weighed and sorted the brass , but it is All lapua and prepped the same way

 

[Rich Coyle]

I have three chronographs and never saw something like that on any of them.

 

[Pdvdh]

If the first shot was from a clean barrel then yes, expect to see a differing velocity. The following shots should be more similar in velocity.

 

[CatShooter]

What phorwath said... I see it all the time.