What is a normal velocity difference between round to round if you measure each load on a scale. The reason I ask is I went shooting and there was any where between 50 and 75 fps. differences. Thanks guys.

My 30-06 full power loads with 190 gr bullets and 62 gr of RL-22 have an extreme spread of 50 fps. Thrown from a match grade dispenser, not individually weighed.

My 30-06 light loads with 110 gr bullets and 16 gr of Green Dot have an extreme spread of only 11 fps. Thrown from a Lee perfect powder measure. Average velocity 2024 fps.

There are obviously a lot of variables. I think in general terms the more powder the higher the spread will be. The lighter the bullet the higher the spread will be.

I am sure there are smarter people than me who can explain better. Just my 2 cents. MM

The thing to look at is not necessarily the fps but the % of deviation. 75 fps difference in a load that has a muzzle velocity of 3000 fps is only 2.5%. That is not bad since the standard deviation would run about 18 with a spread like that and the SD is more important than extreme spread. There are a lot of variables that will affect velocity spread. Temperature changes as you shoot - a cold gun warming and cooling with shots and shade and sunshine will affect the over-all velocity spread more than it will affect shot to shot velocity. If your weapon's temperature was constant and the SD was as high as your spread then it would be something to worry about. Do you know what your standard deviation was?

PaulS

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