Borrowed a few tubes for the Browning this weekend and 2 of them appear to be the same other than not markings on one of them. One is for sure a Colonial IPTPX. Comparing the two tubes the Colonial has a better finish, smoother interior, knurling is flattened and not sharp and the knurling has a definite line where it ends on the choke body.
The unknown tube has sharper knurling that fades into the choke body towards the rear of the knurl band and the porting does not seem to be angled as much. I had a Star Dot years ago but it had straight lines for knurling and not a checkered pattern and from what I remember was real similar to these 2 chokes. The unknown actually shot a fuzz better yesterday but hard to compare as I was unable to shoot the exact same loads from both and they were not cleaned at that time, more range time this week is in order.
My question is, could this be a Star Dot tube and if so is it of the quality of the Colonial?