I'm not exactly sure what you mean about smaller shaft, but I foot all my carbons with aluminum. Keeps them from mushrooming at the point, and makes them about bullet-proof. I use an inch section at the point, and 1/4" to 3/8" at the nock end. 2216's work for my Carbon Express, and 2413's work at the point on Arrow Dynamics Trad's. 2117 works on the nock end of the AD's. I just got a few 2512's that work fine on 23/64 wood shafts. I'll use two-inch footings for them. I saved a CE recently from a Robinhood. The aluminum section split and the shaft did also, but just a little. The aluminum sleeve kept the arrow point from going too far down the shaft to save. A new aluminum epoxied back-on and the arrow is fine again. I use 1 hour set epoxy to secure the footings. Angle the edges of the sleeves with a file or wet-stone to make them easier to pull from targets. Just got a dozen of the AD Trad's Woodgrain I'll be doing this evening. I love building and tinkering with my arrows and gear.