I got a few loads put together with a very irregular roundball from a cheap DGW mold (NEI .662 ordered & on the way.....)
I loaded 90 gr. equivelant FFG only using Hodgdon's Triple Seven, a nitro card, 1/2" fiber wad and a soft 1/2" felt wad.
I used LEE liquid alox on the balls and put several crumbs of SPG black powder lube into the case neck of the unfired plastic cases.
When I used the BPI roll-crimper that you spin in a drill chuck the heat melted the lube nice and even and kidn of seals the cart.
I used no over-shot card...The "roll" curls over onto the ball nicely.
At 25 yds. 3 shots from a rest off the handlebar of my Rokon and two more offhand gave me a group center-to-center of 1.25"w x 1..75"h.

The brass case loads did not seem quite as accurate as the plastic case ones, so I took a poke with one of my remaining brass case loads at the tip of an old chainsaw bar my pard had leaned up against a stump as a 25 yd. pistol and .22 rimfire target.
THe .66 RB knocked a hole thru the roller or sprocket tip about the size of a two-bit coin.

Recoil is lighter than .45-70 and once I get some RBs from that new mold that is (hopefully) on the way that are actually ROUND, I'll try some longer ranges.
I have a hunch that I will be able to keep them on a playing card @ 50 yds.
I am pretty sure that I have a 30+ yd. effective range w/ birdshot.(Imp. cyl. , aprox.)

Haven't put these over a chronograph yet, but should be able to soon.

The "Poor Man's Paradox" was made by back-boring a rifled, heavy barrel 20 ga. NEF.
I am trying to find a mold maker so as to get a proper bullet to try, but the realities in MY world are such that the roundball is probalby more than adequate for my purposes.

It might be possible to take a heavy barreled 12 ga. rifled NEF and back-bore it to 10 ga. if you were in the north of "OZ" where you have water buffalo to deal with, but you will need to buy your own tooling for THAT project. (I had to buy tooling for Clearwater Reboring/Delta Gunshop, e-mail: jim@deltagunshop.com , to do this project, and I would be delighted to share my tooling with anyone who feels like having his own 16 ga. "Poor Man's Paradox" :-)

I have heard that Badger Barrels/Ernie Stallman, is manuf. 12 ga. Paradox barrel blanks for H&H.
I have an inquiry to Mr.Stallman about getting a barrel to re-barrel one of my large Martini 14/12 ga. guns.

Most of the "real world" shots my friends who can judge range or myself have taken over the last 50 years or so on deer and blackbear have been well under 100 yds..
From what I hear about moose, that usually happens pretty close, and feral hogs are NOT a long-range sniping proposition....
Recoil is fairly light considering how much lead you are pushing downrange...
More of a hard shove than a "kick", and it doesn't seem to aggravate my arthritus.

Also, I have followed tiny occassional pin-head size droplets of blood on my hands & knees for 20 minutes (that seemed like a couple hours), with heart-shot deer from .30 cal. rifles, and I don't believe you would have to look very hard even with my dimming eyesight to follow a blood trail from a .63 or larger ball or bullet that has gone thru both sides.

I think a gun like, even a single barrel, would be extremely practical for someone who wants to put some wild meat on the table and doesn't know what he is going to run into when he goes into the bush....
"Grouse to grizzlies", a heavy enough Paradox ball or bullet and 7/8+ oz.shot loads should do it all ;-)

Dave3220 (e-mail: dave3220@mac.com, if you want to find out more about Clearwater Reboring, Rokon trail machines, etc....)