Not sure about the stocks, but I have the PRI C/F front ends on the two AR's now in PD's hands from being stolen (but no, I"m not bitter :cry: ) and anyway, they are LIGHT.
And they both have the 93B stock.

I also had the barrel turned down where it's under the handguards, so it's very light. there's no way the rifle weighs much more than 6lbs.