I retired my CED M2 with a Magnetospeed as its a hell of a lot quicker and easier to setup, accurate velocities and isn't affected by range users, environmental/light conditions, calibers, etc etc. It just works.
It can alter harmonics, but some barrels/calibres are more affected than others, but is a moot point if just confirming velocities. hasn't worried me in the slightest. There are also a number of companies in the US manufacturing adjustable extensions/arms for attaching the bayonet clear of the barrel if needed.
Hit the guys up at Huntsman Aus in Townsville if you want any more info on the MagnetoSpeed gear.
https://huntsmanfirearms.com.au/catalog ... ospeed_54/