All groups were shot at 104 yards.
I cast my bullets this time with a new lyman mould 457677 (20-1) and as I ran out of 2f, I was forced to use Pyrodex RS (not Select).  I also put a 17" 3x William Malcom 3/4" rifle scope on my rifle.  I had also made my own lube and was trying it against some rooster lube.  I keep forgetting about a fouling shot so I ended up with 4 shot groups.
65 grains (measured) went into a 2" group and I was feeling good.  70 grains of RS with a crimped bullet went into a 1 3/8' group (Rooster Lube) and I was excited.  Then I dropped a 75 grain RS load into 1 1/8" using my lube.  I felt good.  I was later able to place 6 bullets with 70/75 grains RS into a 1 3/8" group before I went home.  My groups were shot from the bench using a rifle rest so my shots were as steady as a rock.
 I had some real wild groups but later learned that my scope was sliding in it's mount.  I hope that I have corrected the problem.  I did not blow between shots but I am going to try it at my next range date.
I weighed my bullets and kept them within + - one grain.  (three grain difference)  I continued to use a lube cookie of .09 and a wad of .06 over the lube and one of .03 over the powder.
I found some 2f black Goex and will now try to learn if Pyrodex or 2f black is better for accuracy.
I do not know if I can repeat this day at the range, but I do firmly believe that these rifles are capable of excellent accuracy.  
C F 
ps  These bullets are great.  I have room for 80 grains of 2f with not too much compression.