If you are happy with 70-80gr of powder, it seems PBs are ok. I have NEVER tried them and qualify my opinion as such, but I don't think I've seen issues with them at these low charges.

If you never plan on shooting over 100 yds, there's nothing wrong with this load!! The first 5-6 years I hunted with a ML it was a Traditions Deerhunter sidelock, I used 85gr Pyrodex and a 240gr Hornady HTP and knocked them dead...out to 200 yds. Almost all pass-thrus.

The beauty of MLs is the versitality. Are they a short-range primitive weapon? YES. I still have that sidelock and last took it afield and killed a deer in 2005. I now have an Omega X7, open sights, that replaced it and use for short range work. Are they long range weapons? YES. I should sell the slug barrel for my Remington 11-87, haven't mounted it since 2005-2006 or so. I'm an accuracy freak and so I'm ML all seasons when I can't carry a rifle. My Omega has taken deer too 338 yds, not by luck but because I practice with high power loads to 400 yds (no PBs!!!!).

If you are content with what a PB can deliver at short range, no reason not to use them. If you are not, we are blessed with more good bullets than I care to try and list.