Thread: Accuracy at 100 vs 600 (example). Variations in accuracy at different ranges

Originally Posted by Friwi

I thought the reduction of spinning is way smaller than the reduction of speed of the projectile , therefore more stable as speed decrease.
? ( provided it was launched with a fast enough spin at the beginning to remain stable ,all the way to and sometimes through the speed of sound and beyond)

The theory of the fast projectile going a bit lower and the slow projectiles being thrown a bit higher is the theory used with the barrel tuners I believe

My understanding of the lighter lower / heavier higher was as the barrel lifts in angle with recoil, the lighter bullet is out of the muzzle faster and the heavier one is in the barrel fractionally longer and recoil lift is the cause.

Now myy acceleration maths is a bit rusty , but if a load will send a lighter projectile in my 308 out at 2900 fps at the muzzle and the heavier one is out at 2650 fps then time in the barrel is average speed x length of barrel.

EG 24 inch barrel. Ave speed is about for each is 1450fps for the fast one and 1325 fps for the slow one. so the fast one will spend 1.38 milli seconds in the barrel (1.38 thousandths of a second) and the slower one 1.51 milliseconds. A difference of about 9% (IE 9% longer in the barrel as it is lifting....)