ar15 sporter  has 20" h-bar  w/ flashhider but no bayo-lug

would this gun have the block in the lower reciever?

The upper was manufactured between 1989 and 1994 if it came with the lower originally.. Colt placed a sear block in its lowers starting with the 1989 ban.
So if it is a colt lower made after the '89 ban the answer is yes. FWIW, the block doesn't bother me. Its the damn front hinge pin that drives me fucking crazy. Rifle was made to be broken down for cleaning. Swapped it for a push pin from bushmaster.
Block doesn't impair function at all and can be milled out. Dremel might even work if you've got some spare time on your hands. Not sure if it would be hard enough, though.

Quoted: The upper was manufactured between 1989 and 1994 if it came with the lower originally.. Colt placed a sear block in its lowers starting with the 1989 ban. So if it is a colt lower made after the '89 ban the answer is yes. FWIW, the block doesn't bother me. Its the damn front hinge pin that drives me fucking crazy. Rifle was made to be broken down for cleaning. Swapped it for a push pin from bushmaster. Block doesn't impair function at all and can be milled out. Dremel might even work if you've got some spare time on your hands. Not sure if it would be hard enough, though.

I'm not sure that's right... I have 2 blue labels, one made in 1991 and the other in 1993.  The 1991 model has the sear block but the 1993 never did... go figure.

I bought my blue label in June '90. No sear block. It does have the large hole slab side lower.

My guess would be...slab side receivers = no sear block...fenced receivers = most likely to have the block (as in, most did...a few did not)

There is no logic to Colt models or what you will find!!!

I have seen ONE Large pivot SLAB sidded lower with a sear block! (Pre-Ban)  Now I have only seen one like this and I was told that it may have been then end of the slab sidded lowers that they were finising up.  Regardless it shows another example with Colt that there is no steadfast rule that seems to apply!

The combinations of colors, Large vs Small pivots, Large vs Mil Spec Trigger Pins, Block vs. No Block, Drilled for front push pin or not, etc., etc. is very difficult to predict.

I have a pair of pre-ban colts that are both small pivot, mil-spec trigger, blocked.  One a Sporter Target is not drilled for the front push pin while the other, a Sporter Match HBAR is drilled.