In tuning my Impact M3 I realized there was too much to test and information to keep track of, so made the attached form to fill out at the range as I shoot. I hang my targets and shoot methodically, assigning a number to each target. At the end of the day I'll go back and measure the group size for each target and record them in the "group CTC" column. Once I've done that I can discard the targets. I'll have a good idea of what worked at the range but this leaves no doubt. From all this I've made a short list that essentially reads, "this projectile, these settings, this velocity".
Also, for the M3, I used to measure the distance the valve adjuster was turned out with calipers but it was a slow process. I have since put a white stripe on the end of the knob (like the hand on a clock) and found that a 1/4 turn is equal to about .010". Now my valve settings are recorded as 4 1/8, 4 1/4, etc. Easier and faster.
View attachment Impact M3 tuning record form.pdf
Also, for the M3, I used to measure the distance the valve adjuster was turned out with calipers but it was a slow process. I have since put a white stripe on the end of the knob (like the hand on a clock) and found that a 1/4 turn is equal to about .010". Now my valve settings are recorded as 4 1/8, 4 1/4, etc. Easier and faster.
View attachment Impact M3 tuning record form.pdf
