You can use arrow shaft, either alum or graphite. The reason is to use just a little exopy and not add weight in the wrong place. You can also buy an epoxy filler that is basically micro-spheres that will lighten the goop and still have enuogh strength to stiffen the forearm without the tubing. I would do any of this before bedding the barrel as the weight will change how the gun handles.

I have a Savage model 116 with a synthetic stock. The stock is factory pillar bedded, and free floated. The rifle shoots decent groups (3/4"), but the stock is very flexible. I notice a point of impact change when I switch from sandbags to bipod. If I full length bed the stock will it stiffen it enough to keep the point of impact from changing? Will I lose accuracy by going to a full length bed vs. a free floated barrel? Should I give up and buy a stiffer stock?

I don't think the best bedding will help a too flexible stock. Scrap it and get something stiffer.

Joe

The point of impact problem may have more to to do with how the rifle recoils off the bags versus the bipod. If the barrel is really free floated, flex in the forend shouldn't matter, unless it flexes up far enough to contact the barrel in one of your firing methods, but not the other.

The stock contacts the barrel occasionally when on the bipod. If I hold the barrel in my hand and press on the stock I can push it over until it touches. I was hoping that bedding the barrel towards the front of the stock would be enough to keep the pressure consistent.

A guy that posts by Buzz over on Hunt America has posted or can send you instructions on how he has used bedding material and aluminum (?) rods to stiffen the factory Savage stocks without actually full length bedding the barrel. Otherwise, Cabela's sells a pillar bedded Bell & Carlson synthetic stock for Savage heavy barrels for ~$90 I think. Not sure where to get one for sporter weight barrels.