Thread: Lower than expected velocities

Greetings @Longrun and all,
I have found some significant differences from published data in the 6.5-06 and I expect that the .25-06 is much the same. A new pressure barrel which is made to tight tolerances is always going to deliver higher velocity and pressure than one which has had considerable use. I always look around the various data sources and use the one that is closest to the chronographed results I am getting. Stabal won't have the range of data being so new.
With the 6.5x55 there is plenty of data for W760. 47 grains is right at the top of the data I have looked at although the 6.5 is loaded to a lower pressure than other cartridges. Some years ago I worked up to a velocity of 2,923 fps with the 120 grain in my M38 6.5 with a 24" barrel. you would lose 100 fps or so in your 20" tube. My load which will not be divulged or repeated is well above current max loads as is your load of 47 grains of W760. Nosler list 45.5 grains and Hodgdon 44.5. As mentioned these are for the M38 Swede rifles and you don't mention what your rifle is. In a 20 inch barrel 2,750 fps is probably about right.
Regards Grandpamac.