Thanks for the link Sundog! I will probably use the Oregon Trail bullet for cast loads though.
LeftoverDJ, this is exactly why I consult burn rate charts, pressure curves and load data. 748 and 335 may have been close to the same in the past, but saying they are the same is a misconception. Primex makes both powders, but to the slightly different spec's from Winchester and Hodgdon. They are from the same base chemistry, but 335 is slightly slower than 748. Some reloaders state that HP-38 and W-231 are the same. Same can be said for W-540 and HS-6, but I ain't buying it, not even for a dime! If they were even close to identical they would show up back-to-back on the burn rate chart. The only two that do are H-380 and W-760 and they are not the same exact powder. The only identical powder that Primex makes or made for two different companies is the former WAP and the presesnt Western Powder Co. (Ramshot) Silhouette. They are identical in every respect and load data is completely interchangeable. Is this the case for W-748 and H-335?
Thanks to everyone for the input. W-748 will get the nod for now with the Sierra 150 gr. JFP and the Remington 150 gr. Core-Lokt!