In 44 caliber may favorite bullet and weight are 280 gr WFN, driven at 1200 fps. At that speed your S&W will live a LONG time, gas checks won't be needed if the bore is smooth and bullet fitted properly, and deer fall over dead in their tracks if hit in the chest. So I don't take more pounding than need be.
300 gr is a bit heavy for S&W's, partly because recoil is more painful from them than other revolvers, and partly because the double action get shook up too much. However, if you'd have had a 300 WFN which I had made, and if LBT bullet lube were used, 1400-1450 fps would have been easy to obtain in your Smith. Gas checks will give a bit more speed than pb, with lower pressure, with a given load, or if the powder charge is upped to match pressure with a PB bullet, velocity with the same weight gc bullet, (if seating depth is same also) will be at least 100 fps higher. Likewise, using LBT lube will yeild higher speed, lower pressure with a given charge compared to any lube I know of, and especially the wax used by Cast Performance.
Lets consider the most popular bullet lube, alox, and a 250 gr 44 Kieth style bullet, compared with a 250 gr LFN gas checked of my design, with LBT lubricant. Both bullets loaded to standard max pressure of 40,000 psi. My bullet leaves the muzzle at between 200 and 250 fps faster. The WFN in the same weight has a bit less powder space so will only gain about 200 fps over a PB Kieth style SWC.
But then, who cares how fast GC bullets will fly if we don't WANT maximum speed! With LBT lube, 1400 fps without a trace of leading is an easy speed with PB, and you'll get that speed easily with the 280 WFN PB. GC is capable of 1550 fps in 6 inch and longer revolvers, including S&W's but thousands of rounds will beat them up. Rugers don't mind the pounding at all.
