I think a few random posts at ARF compelled me to try and find the tear drop forward assist buttons for my Mk18 builds, but recently, I have been assured by the hive that they are not necessary to make a build perfectly clone correct. Some of the earlier Mk18s were built by Crane from M16A1s and some were seen with tear drop FAs, but my clone would be fine without one.
Well, I got bored one day and ordered a few anyway. DPMS units from Brownells. I wish I could find original Colt ones, but these are good enough for me. Besides, one of my other rifles had a Colt Expanse upper and didn’t come with an FA so this was a perfect excuse to transplant an original Colt F/A onto the expanse upper.
The FAs are pretty easy to swap out. Just punch the roll pin out and the FA assembly comes right now.
Comparison between the DPMS tear drop FA with the factory Colt unit.
To get the new FA in, I partially tapped the roll pin back in before inserting the new FA
Push the FA partway in and with my spare hand I can tap the rest of the pin in.
The FA cover from the Colt Expanse upper.
It comes out the same way except there's no spring inside.
Since I ordered two of these things, I figure I may as well throw it onto my Block II build. I have seen pics of Block IIs in the wild with the tear drop FA.
Anyway, I don't think it looks bad on either the CQBR or the Block II build. I don't really use the FA much but it was an inexpensive modification.