We bring two chronos to our games. One set to .25 and one to .28, which covers most of the ammo brought. The one with .25 has all the weights programmed in and can be changed quickly to any weight the player is using (from .20 up to .38).
This last weekend we had a couple of guys that where just over the 425 limit on one or two of the chrono shots (427 and 428) but under on a couple of others (420 and 421). No big deal.
We did turn away a gun the was running 525 FPS. Player had it fresh out of the box. He was told to go get a different gun to game (he had a couple) until he downgraded that one.
Nothing says loving, like a head shot!