weights are available on the GM website or about any of the auppliers websites.
The lightest barrel available a few years back was the 13/16" .45 caliber in 36" length. A 3/4" .36 cal might be lighter, they didn't have them then.
I was making a lightweight poorboy due to back surgery. I got it down to 5 1/2 lbs. You talk about one slinder rifle! Lock stock and barrel, two lock screws and a sheet metal rr thinble. It is the best shooting gun I have owned for the past 10 years.
My wife confiscated the gun on sight after we met.