The rails are different.
On the ones you linked they are the Midwest Industries rails.
On the mk2's they are Centurion's.
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I picked one up earlier this month. Already switched out the stock, grip, etc. I've only put one mag through it, but it felt great. Mid length on these really shines. I do like the trigger and muzzle device.
These are probably the best complete offerings I've ever seen since becoming a member here. BCM hit it out of the park with that carbine series. :cool:
I'll be wanting one of those Precision 18's. When will they be arriving at G&R :D