All Alliant's "recipes" have always been maximum loads. They expect you to know for yourself that you have to knock 10% off to start. I don't recall ever seeing a pressure number from them, though Lyman has pressures where they use Alliant powders.
As to lead pressures, despite the wider diameter, lead bullets take much less pressure to swage into a barrel. If you don't believe it, try using a brass rod and a mallet to drive one through a bore. Then try the same thing with a jacketed bullet. The cast bullet might be BHN 15, but the copper jacket BHN is often around 60, so it requires a lot more engraving force.
Lead bullets typically produce lower pressures except for magnum pressures in revolvers. Skeeter Skelton commented long ago that in magnum loads he had more pressure signs from lead in his revolver loads. This is likely due to the softer metal blowing out to pretty much fill the forcing cone and sealing off the chamber of the revolver before finding its way into the barrel. If you look at a reprint of F.W. Mann's 1907 book, The Bullet's Flight from Powder to Target, he has lots of pictures of the result of gradually cutting a barrel down until the bullet was starting out at the muzzle (pretty much what a revolver chamber is) and the lead bullets all have the profiles of Christmas trees after firing with the peak pressure right behind them.