Back when this subject (forcing cone erosion)was a hot topic in the Ruger .357 Maximum revolvers, some of the suggested causes were the cartridge itself, lightweight bullets at high velocity, Lil Gun powder, and barrel cylinder gap. Now, some 20 plus years later, the prime culprits are Lil Gun and the 260 gr. XTP bullet. Although FA is known for its tight tolerances, it would be interesting to know the BC gap on the affected revolvers.