I think Ken has a lot of experience shooting the .50's in the FA, and his articles in Sixgunner proves him out. Shot Jack's BFR in 500 JRH in February, that BFR actually made, and the gun was pretty tight!. Just got my BFR this past Friday from Jack. I sent him a 454 BFR I found for a great price locally, and had him convert it to his 500 JRH. He put a 4" octagon barrel for me, and rounded the grip some. I originally wanted a bisley grip, but he could not locate any? The modified grip seems to handle the loads, and I'll play with it. I'm spoiled with carbide dies, so went with 500 JRH. I like the quality of the FA(have had several), and almost got a 500WE, but just couldn't get a local shop, to drop the price on a 50AE he had for a long time in his shop. Would have probably had Jack do a 500 JRH cylinder too, if I got that FA? I think the FA will take a lot more pressure, and looking at FA data, they are really getting some great ballistics, with their slightly shorter case, compared to the 1.4" length JRH. Jack said he could probably load the JRH just as hot, but said he didn't need to. As I get older, I'm not pushing my recoil limits like I use to in my earlier days. Have read of too many folks really hurting themselves. And as Jack told me, they have been dropping bison with the Buffalo Bore 440 @ 950 fps load, with great results. Load is so comfortable and easy to shoot, and puts enjoyment back into my shooting sessions, where in my earlier days, after shooting a bunch of hot loads, soon dreaded shooting the next shot. For me, I like cranking my ammo out quick in my Dillon with my carbide dies. But if I did find a cheap FA 50AE?
?? As been said, both cartridges are pretty much the same, but the 500 WE is a FA chambering. But then again, Jack originally designed the 500 JRH to fit the FA platform? Plus a couple of my buddies like to shoot my 500 JRH ammo in their 500 S&W's.