Sig 716 roller inside of upper

[88GFY]

I have 2 716 uppers (piston). One is 12.5" and it has a weird roll pin in the upper. The other is a 16" and it doesn't have a roll pin in the upper. My 16" bcg does not fit in the 12.5".

Any insight is appreciated.

If anyone has a 716 could you check if yours has this roller/pin?

Thank you!