The readings with the LR were consistently higher.
I recently put together a 300 Ham'r and have been following Bill Wilson's writings on the cartridge. He has reported the same thing, I believe along the lines of 20 fps, in general.
I have one, along with a Magnetospeed and an Oehler 35, and to keep things consistent, have pretty much relied on the Magnetospeed to get velocities with that cartridge due to that's what I started load development with.
The MS and the Oehler agree with each other within a couple fps, so I'll have to directly compare the MS and LR as the subject of a range visit....Damn, that means I'll have to shoot some more. Bummer....
The LR sure is convenient and I really like being able to calculate real-life BC.
