A number of years ago I made some fiberglass and polyester resin stocks with balsa wood cores. They finished out at approximately 11 to 12 ounces. Because the stocks were so light, you could still use the inch and a quarter barrel and make the light weight requirement; but needless to say they changed the rules. The workmanship on this carbon fiber stock and the shape of the stock is outstanding, but there are some limitations with the interior. The balsa wood is fine. The stock has a red Cedar core, which can be sensitive when you glue a pillar into it with very little surface area. The reason is because red Cedar has its own natural oils, which is why they make red cedar shingles to repel water and bugs, and last for years.. If a piece of instrument grade spruce was used for this, similar to the spruce that I use in my FT/r stocks, this might be a better solution. Spruce lends itself to almost every type of glue available and is more rigid. Countless number of airplanes have been built from Spruce including the Spruce Goose. The following pictures depict what I did to solve some of the problems. I removed the red Cedar and replaced it with a pillarized bedding block. I added an adjustable buttplate that is adjustable for up-and-down and cast on cast off. The rifle still makes FT/R weight with an F / Open size barrel.