I thought I seen somewhere that. The pro model has a different firing pin??????
Pro model has a rail,polygonal rifling, loaded chamber indicator and comes with 2 13 round mags and is rollmarked PRO
The non- pro comes with a 10 round mag and none of the above list.
I have a UC non pro with well over 2,000 rounds of Blazer Brass with one stove pipe with in the first 100 rounds