TH44...I sent you a PM with the number you asked for. Thanks

I measured the bores more carefully today. 1" in front of the chambers the right measures .510" and the left measures .509" in both cases the bore measured .500".

Based on experience gained loading for the 50-110 WCF I worked up loads using the 440gr Woodleigh bullet, with 4759 and 5744 powder. These were 50gr 4759, which chronographed at 1737 fps at an estimated 19,900psi. This is the load I fired for groups and was quite well regulated. The other load I developed (because those SOB's at Hodgdon stopped making 4759) was 56gr of 5744. This load chronographed in the right barrel at 1728 fps, and the left barrel at 1721 fps. With an estimated pressure of 19,800 psi. Pretty darn consistent.(both loads using .5" backer rod wads and mag primers)

IMR 4759 works wonderfully in these long cases. In fact I think it is the same as the powder Winchester loaded in the 50-110 300gr express loads giving 2200fps. I'm really disappointed that it has been discontinued. 5744 works pretty good, but not as clean as 4759.

According to my calculations 55gr of 4759 would exactly duplicate the old nitro for black load using cordite (55gr for 1900 fps @ 23,900 psi) But I don't think I'm going to try it in my 135 year old very valuable toy. There is just no benefit that would equal the potential cost of such an experiment.