Posted on the varmint forum also...

this is for the interested.. not an invite for debate from those who don't like Blue Dot in rifle cartridges.. we have beat that one to death..

per request, I went out and chrono'ed these.

Temp: 108 degrees
Rifle: Model 70 Varmint 26 inch barrel.
Primers: Rem 9 1/2
Cases Used: Winchester

Load 1: 18.5 grains of Blue Dot
a). 40 grain Sierra HP: 3558 fps, 3559 fps
b). 36 grain Barnes Varmint Grenade: 3680 fps. 3700 fps
c). 30 grains Berger Varmint: 3515 fps, and 3515 fps

Load 2: 19 grains of Blue Dot
a). 40 grain Sierra HP: 3619 fps, 3627 fps

Load 3: 19.5 grains of Blue Dot:
a). 40 grains Sierra HP: 3660 fps, & 3675 fps

Load 4: 20 grains of Blue Dot
a). 40 grain Sierra HP: 3668 fps & 3715 fps...

What I left out of the above was the results out of an inital cold barrel. These were fired during 2 sessions. Both times the temp was in the the 108 degrees range.

Both loads were with a 40 grain Sierra HP.. With an 18.5 grains of Blue Dot charge, the intial MV was 3918 fps.. and with a charge of 19 grains of Blue Dot the inital MMV was 3957 fps.

the second shots were having MV in the range of the 3550 fps range.for the 18.5 grains and 3600 fps for the charge of 19 grains of Blue Dot. This presents an interesting scenario. Is blue dot NOT temp sensitive, or considering the results, does its velocity actually speed up as the chamber is cooler and then slows down as the chamber heats up?

cheers
seafire