Poly lower saves a pound

[Jkinpa1]

Here is an interesting Excel spreadsheet for anyone interested, I stumbled on it doing a search for weights for a recent Colt 653 clone build, its pretty thorough

AR15 Parts Weights Database:

https://docs.google.com/spreadsheets...#gid=102399689

Did you create this? Can you explain it a little, or maybe direct to an orig posting?
I think it’s really interesting, just not sure of a few things...