I'd get it closer. Have used Magnetospeed for years and using the square aluminum spacer supplied is the best way to figure height below bore. If too high it won't read reliably. I used the straps for years and they work fine. You have to play with them a little to get them set up but they work. I got a Wiser Precision mount this past year to hook to ARCA and it works great. Easy to adjust when going from rifle to rifle.