It has the "H" buffer which slows it down a little. I think without the can it is running around 800rpm.
I tried shooting it with my suppressor that day and it sped the ROF up way too much and was jamming so severly that it was buckling unfired rounds.
But that was using a Colt FA bolt because I didn't have a LMT bolt. I called LMT ordered a LMT bolt with the "crane o-ring" and they assured me it will run fine with the suppressor with that bolt. They also suggested with the can that maybe I would want to try an H2 buffer.
It isn't to uncommon for guys to use adjustable gas blocks and bolt weights to get the ROF down to about 600rpm on a M16.