A bullet doesn't shoot flatter because it is lighter-it only shoots flatter if it is moving faster. This is NOT theory-it is fact: All bullets drop to the ground at the same speed due to gravity, so what determines how high or low they hit on the target is how much ground they cover horizontally while they are falling to earth. The faster they go, the less they seem to drop in relation to the target at any given downt=range distance.

A lighter bullet, despite being launched faster, may not shoot flatter at extended ranges if it loses its' initial advantage in speed too quickly, as happens if the bullet haspoor ballistic properties. Use a bullet with a high ballistic coefficient, and shoot it at as high a velocity as you can safely get, (with the required accuracy, of course!).

It sounds to me like your group starts walking when the barrel heats up. This is not unusual, but it is annoying!!

Next time you go to the range, take another gun or two along to shoot while you let your ML sit and cool down after each two shots. If it shoots OK for the first two shots, use those two to zero it in. In all liklihood, you'll never get more than two shots at game anyway. Probably only one!