ReDoT
Nice field test info.I have to agree with you on twist rates.I tried Buckhammers in my Marlin 512 Bolt action slug gun witha a 1:28 twist and They were everywhere on the target with extra holes.The sabot was seperating from the slug before impact.I contacted Remington and they informed me that they tested with a 1:35 twist rate.
I'm surprised you had a problem with the Federal Barnes Expanders.The ballistics for them is exactly the same as Copper Solids and I shoot them exclusively in my rifled barrel guns.I consider the Barnes bullet slightly superior to the Remington.But They are too damn expensive to practice with,that why I usually shoot Brenneke KO's in a smoothbore.The longest shot I have ever gotten,hunting in heavy timber,is 75 yards and the cheap stuff shoots as well as the budget buster ammo.I still want to test the Federal Tru-Ball slugs.

Bill