I just had to try...
I only have the 1851 Colt so far, and have not done the conversion yet. i do not have any of the Black Hills test ammo yet, nor do I have the .36 Remington. I was getting impatient, though, so I did pop the cylinder in with unmodified 1851 just to try.
At 7 yards, two hand unsupported firing stance in the back pasture, I tried some assorted 148 wadcutters.
First I tried 5 rounds of no-name bulkcommercial reloads in mixed brass. I used a puller, and they do have a hollow base wadcutter, but they seem pretty hard. All five rounds key-holed completely and spread about 8 inches! That was really discouraging!
Then I grabbed an old box of Western (Winchester) Mid-range 148 HBWCs. 5 rounds, all nice crisp crisp holes, about 2.5" spread with one clover leaf. That's much more encouraging.
The WWs seem to have a soft lead wadcutter, whereas the commercial reloads were hard like 1/20 tin or even wheel weight.
I won't be doing anymore until after I get the ammo from Black Hills, the .36 Remington, and do the full conversions of both revolvers. I will do a range session with pictures and tabulate results. I am guessing that it will be some time next month before I have more to share, but it is nice to know there is some hope for hollow base bullets.