Originally Posted by Seven Oaks
I just ordered a Speed Dial for my Nikon Monarch X 2.5 x 10 x 44 Scope.
I'm mounting it on an X-Bolt 7MM WSM. I'll shoot Win. Supreme 160 Gr. Accubond.
My question is how reliable are the Factory MV's on winchester short mags?
This round has a published MV of 3050 fps. Since I got a 23" tube, my ballistics program put my MV at 3020 fps and that's what I used on the order form.
Just wondering if there is some "Blue Sky" in the factory published MV's. and if I screwed up by not running the stuff through a chrony?
Most factory muzzle velocities are hard to match in factory rifles because they are tested in
custom barrels. and are the highest velocity reached not an average of all shots fired.
And most of the barrels are 26", most factory hunting rifles are 24".
The only ammo I have ever seen that reaches or exceeds listed velocity is the factory
Weatherby ammo in Weatherby calibres.
If you have a slick Custom barrel they will make up about 50 ft/sec from the 50 ft/sec lost
in a standard factory barrel, so they will be close to listed velocities.
Always verify velocities with a good chronograph and use the average, if the highest velocity
matches the factory that's fine but use the average for trajectory calculations.
J E CUSTOM