Yes, it weighed just over 40oz with an empty magpul mag inserted when i weighed it at the SC state match.
It started out just like this thread as far as i was just trying to add a few more ounces to a CO gun for the heck of it. I learned that you could easily add 3oz to 7oz to a glock but i really couldnt think of much beyond that (2oz over stock weight with an extended 1/4" thick tungsten guide rod and then 3 to 5 oz in the grip depending on what type of tungsten you used and how permanent it was). I then i read a thread on the sig 320's and about what some people have done to the grips as far as chopping them up and adding tungsten and putting them back together and i figured what the heck, i enjoy tinkering and the worse that can happen is i ruin a frame.
I shoot my glocks with a medium size grip so i wanted to make sure when i was done that it was still a medium size grip. I used the extra backstraps i had laying around and i made a template on the grip size and i could always take measurement off my other glocks as i went. The first thing i did was chop away most of the back grip area with the exceptions of a few small strips of plastic left (to give something to attach to and help keep the basic grip shape). I then went layer by layer with tungsten plates, blocks (two different sizes), and small scrap pieces of tungsten to build up the basic shape of the grip (solid tungsten adds up very quickly). Before i started, I also roughed up the plastic surface pretty good, made small little attachment points in the plastic for the putty to tie into, and tied small stainless wire into the plastic to kind of act like rebar. All the tungsten layers are held together by devcon steel putty (slow setting stuff). I took quite a few different evening getting the basic shape of the grip built back up but once that was done i did lots of skim coats and then sanding to get the final shape i wanted (devcon steel putty mixed with tungsten powder since this part was just cosmetic and not structural). I then covered it all with a silicon carbide grip job so you cant tell anything was changed unless you pick up the gun. I forget the exact weight break down but it has a tungsten guide rod and some weight is in the lower part of the grip on the left and right hand side where it flares out slightly on the gen 5's where i just made it a small transition from mid grip to where it flares out and then the rest is where i cut the back part of the grip out and built it back up.
I did this 6 months ago and i only have 3,500rds through it since then so we will see how it holds up long term.