Thanks Mac
and a darn nice shooter too
[/b]
Went out again today to fire two more groups of three each over the Chrono since I added one more grain of powder. these two came out at .565" for the Speer and .430 for the Nosler BT's.
The aggregate for five consecutive groups with two kinds of bullets is
531+563+ 565+312+430= 2401/5=
.480 Av. not just a single isolated group. It looks as though this accuracy is repeatable.
Vel for the Speer 3114 ft and the Nosler BT's 3134
I also ran the 75gr V-max over the Chrono @ 3401 Av. These bullets are tack drivers.
Quick Load predicted 3162 for the BT's and 3144 for the Speer @53383 psi. Since the actual vel. is lower than predicted 53K would perhaps be close.
If I adjust the powder factor to conform to the velocity the prediction would be a bit closer. But then this can of powder is almost gone so I wont change anything. Besides it is only arm chair math.
By the way I made the cases from Fed 270 brass. They have 1.0gr less Ho2 but allows for an excact outside neck reamed neck wall of 0.0122" for minimal expansion of 0.002" with the expander ball for BR uniformity and concentricity.
This is really tough brass and very uniform. No stuck cases. No gap trouble, the putty job is doing well..
Are Handi's tough to tune, you bet this one was.