I've been toying with the idea of getting Accurate to make a mould for HB then I can make my own HB pin. Tom can't cut the big groove the way the Kynoch original was (like the CBE) but he can make come close. With the HB it might work for smoothbore but mostly it would drop weight to a reasonable level.
If launched mildly apparently even the really heavy slugs aren't that bad to shoot. I've shot 800 gr. slugs but those were over a healthy (unhealthy for me) load of Blue Dot. Those weren't too pleasant to shoot! Greg Sappintgon says his 1000 gr. slug isn't bad at all at around 1000 FPS but it still penetrates deeply. Those heavy slugs are hard to stop!
For the most part though I figure 400 to 600 grs. is a "sweet spot" for weight of 12 ga. slugs. Less lead consumed, less recoil... at least with hefty loads and plenty of poop for most needs as Randy points out.
Since we're on an "slug alloys" thread that comes into it too. I mostly cast from range scrap or ACWW and sometimes oven heat treated WW. I used to cast my Lyman Fosters from pure lead. So far I have had 0 problem with leading even with the pure lead slugs. Not sure how it goes with rifled guns as I have only shot one rifled gun and about 15 rounds of unlubed ACWW 0.735" RB's went through it. Not a spec of lead came out.
I can see soft lead slugs causing some grief in rifled guns though.
What I will be interested in is a range report from rifle vs gun with pics of recovered slugs if possible. I'd like to see if his soft lead CBE Paradox slugs mushroom well. I expect they will but would like to see some. If I ever get one of those CBE moulds I'd like the HP version just because but it is substantially pricier then the solid version. I guess if a guy like me wants a few HP's its likely more cost effective to drill them. I do like recovered mushroomed boolits!
Need pics of mushroomed Paradox boolits!
Longbow