Quote Originally Posted by Randy Bohannon View Post
Anything hanging off the barrel will affect the harmonics, for better or worse.

several companies make barrel tuners which screw in and out to “tune” group sizes.

i tried a magnetospeed and found it made groups open up on two of my rifles.

given that introducing unquantifiable variables is an anathema to good reloading practice, I err on the side of caution and use a conventional chrono.

did you shoot the factory ammo with the magnetospeed on the harrel?
Factory ammo was pre-magnetospeed.

What I have concluded is that what I thought was an optimum load, probably isnt. I chronographed to see why some of the groups were poor after sticking to what I believed was a good load. I assumed it would be related to inconsistent velocities etc. It does not seem that way.

I’m going to look at the load again and once decided upon a reliable OCW I will stick with it and just use the chrono to fine tune the load without making too much of a fuss about exact group size. Once I have chosen the load with a good velocity, low SD and ES I will check the final result without anything else added to the barrel.

I think I may have made a bad call at the first stage and have struggled since. A morning at Bisley should resolve this once and for all!