Trying to keep my 300blk build as light as possible. What are the "lighter" BCG's made of? Anyone have any suggestions?

I've been researching lightweight BCG's as well.  There are the steel BCG's that have been fluted or drilled to reduce weight.  These are just .5 to 1.5 oz lighter than their full mass counterparts.  BCG's with significant weight reduction are made out of either aluminum (JP's Ultra LMOS BCG for example) or titanium (Boomfab's Titane BCG for example).  Those are pretty exotic and pricey, but lower weight 5 to 6 oz. over full mass steel BCG's.  You'll need an adjustable gas block (more money) to use these exotic BCGs.  I'm still on the fence if I want to spend that kind of money on my next build.  I'm not a 3-gunner, so it doesn't make a lot of sense for me.  Someone talk me into it, please

FWIW, the Gemtech suppressed bolt carrier 5.56 model will work for 300BLK.  It's made of S7 steel (whatever that is) for lighter weight and better heat dissipation.

http://www.gem-tech.com/store/pc/GEMTECH-5-56-Suppressed-Bolt-Carrier-55p1149.htm

The SBC in unsuppressed mode can be used on an unsuppressed rifle or suppressed rifle.
The SBC in suppressed mode can only be used in a suppressed rifle, otherwise you'll have failure to extract/eject/feed.

I haven't found a weight listed anywhere online and my copy doesn't have a weight listed on the box.

S7 isn't any lighter than 8620 but it's a hell of a lot stronger.