Good investment !
Tried this item today with 2 large frame Glocks in 45acp and 10mm. 10 rounds of 45 and 50 rounds of 10mm comparing handloads to factory ammo MVs, this little item made the task soooooo simple once I got it figured out and mounted. Without this I would have to have used the non-gun mounted chronograph on a tripod ahead of the firing line at my club, and with other folks down the line that would have been too much interruption of their fun. Highly recommend for any numbers-a-holic chrono user (if you have the one this is made for, that is !)
functional but fiddly
The V3 Rail Adapter works as described to connect a Magnetospeed to a Picatinny rail. My only complaint with it is that its a bit fiddly to attach. Basically the two black parts that apply pressure to the rail can spin 360 degrees. So you have to line everything up right to get it to connect. It works but there should better way. Its almost like this was a early prototype that some how slipped out to the public. I was concerned about the offset created between the Magnetospeed bayonet and the bullet path considering in the manual for the chronograph they stress 1/4 between the two. Its a simple fix though, just increase the sensitivity. Mine seems to work at a sensitivity of 5.