Sounds like it's a reference to starting loads for BP handguns maybe? Hard to believe they suggest powder equivalencies to bullet grains of ML rifles 45-cal and above.
Also, what's the sense in starting with 50-60 grains anyways, if you plan on shooting beyond 50 yards.
Every hunter I've been in the woods with wants a load that harvests 100 yards minimum.
Most inline hunters today double-that-amount. Most ML inline boards are discussing loads that reach as much as 400 yards nowadays.
My very first load with my last five purchased MLs was 80 grains. I recommend that as a starting point. Heck, I only increased another 5-10 grains from that 80 number, before settling on a permanent load, shooting 180 grain and 200 grain sabot/bullets, using Blackhorn 209 powder.
The sense is that you don't have to use a big powder charge for practice and plinking, or small game hunting, even with inlines. At about $.50 a shot for a 100gr equivalent load of BH209, practice with full-power loads gets a little pricey. Bulk cast or swaged bullets are about half the price of regular jacketed. PRBs and real BP used in traditional guns are even cheaper, although regular 209 primers are cheaper than #11 caps these days.
