Is the Magnetospeed the one that straps onto the end of the barrel??
If it is, wouldn't that change the harmonics of the barrel (aka effect it's accuracy)???
Yes,It straps onto the barrel. No,It doesn't affect accuracy,but it will change the point of impact a little.About like installing a suppressor on a rifle,the POI will change a little,but the groups will remain pretty much the same.
I absolutely love my Magnetospeed V3. The speeds are a little different than a standard style screen chronograph.Being that it records the actual muzzle speed,it will show faster fps speeds than a chronograph that is placed 15-20 ft in front of the muzzle.
I've not had any problems with my ballistics data and shooting dope using the V3's data shooting long range.It has been as reliable as any other chronographs that I've used.