My little barrel project has me looking at why I have these parts laying around.
I have the barrel because I wanted a 6.8. This barrel was in the parts bin because I had replaced it with a different one. That replacement was panic coupled with cosmetics. This barrel was giving some mild pressure signs. A cure was recommended, but I bought a spare barrel just in case the cure failed. Of course, the cure worked; but I liked the looks of the heavier profile of the new barrel with the 4-rail and such.
The spare 604 upper was bought to get vintage rear sight parts and a correct '68 ejection port cover. The early slip ring came with this upper; I had to buy a weld ring and snap ring for it.
I am not sure where the barrel nut came from. It could be from one of the guns I added a free-float tube to. I just don't remember.
I think I bought the post-ban front sight base and taper pins for my XM177E2 (Sabrina) project. I think that was a "just in case" I couldn't find a 0.625" at the gas port pencil barrel with a sight already mounted. I think. I really feel like this was for Sabrina, but I cannot for the life of me figure out why I thought I would need a 0.75" at the gas port no-lug front sight base.
So, I ended up with a bare barrel and an undrilled front sight base...
Parts just BEGGING to be put together.
This is how spare AR parts turn into guns.