They offered to send me six for free. I loaded up 5 of the 240 gr SWC in 44 special cases with 8 gr of Unique. I shot them over the chronograph then gently swabbed the barrel and noticed mild to moderate leading in my FA 97. This load ran about 1050 fps. Is this too fast for this bullet? I noted that this bullet is listed at .431 and cannot be pushed through the throats by hand. Should I get more and try a different load or is this bullet not right for this gun?
The bullets are probably too hard for that kind of load. If the pressure is too low in the load and the bullet too hard, the bullet will not obturate into the groves. Flame, fire, extreme heat from the powder burning will flash around the bullet and actually melt and plate out lead into your barrel.
There is a calculation that one can use to determine the proper hardness of bullet to use for a given load pressure. Here is a link to an article that might help you. It has the calculations on it.http://www.grantcunningham.com/blog_files/15e296c61415e831fecfe8fddcc1dc92-414.html
I believe that the Oregon Trail bullets are about 18 brinnel hardness or higher. That hardness will probably match pressures up over 32,000 cup. Check your load manual for pressures of various loads.
As an example, I just tested out some loads using Missouri Bullet Co. bullets. They are Brinnel Hardness of 18 and my loads were roughly 26,000 cup. Guess what I have to clean from my barrel now? LOTS of lead.
Aside from hardness, sizing is a big factor as well. When in doubt, slug your barrel and mic the bullets. You should be .001 to .0025-ish greater in size with cast bullets. Preferably .001".
Hope that helps.