I have the BuckShot III BPI manual. It's got more buckshot loads in it than Lyman's 5th edition. Just for instance, It has about 32-33 loads for 3" 12 gauge. However it's limited in certain hulls. It has one 3" Cheddite, 4 with Federal FB, 16 Fiocchi loads, 6 BPI Multi-Hull, 3 Rem, and 2 Win AA loads. Then it uses all BPI filler wads or wraps and most all BPI wads. Also Fiocchi uses Fio 616 primers. None use buffer.
For 12 gauge 2 3/4 buckshot loads they list approximately 90 loads. There is about 24 loads with Win AA hulls, 5 Rem hulls, 11 Fio, 2 Cheddite, and 5 Fed GM hulls. All the rest are BPI MultiHulls. Just about all of them use BPI supplied wads, wraps, and gas seals plus I see only one using a buffer.
About 40 16 gauge loads and 8 20 gauge 3", about 40 20ga 2 3/4", about 30 28 ga loads, with 8 .410 loads, and 20 10 ga. loads.
There is excellent information on loading buckshot with stacking guides, assembly procedures, how to use loading tools for crimping, with descriptions of all the components they use. It has a how to pattern your loads section and what effects patterns.
The manual is very good BUT be prepared to order components to load your buckshot loads from BPI itself. Like I said, most all wads, wraps, gas seals, etc. are mostly BPI. And not a lot of common Win and RP or Federal hulls used. Several but not a lot.
One unique thing that BPI does is it doesn't list "9 pellets of 00 buck" or "25 pellets of #4" but it tells how much that buckshot weighs and has charts but in the reload data it gives shot type and a weight. For instance it lists 1 oz,
1 1/4, 1 5/8 ounce etc. instead of giving you the size buckshot and the number per load.
Hope this gives an accurate summary of the BPI III Shotshell manual. Just so you know that most loads use BPI components. Just to add that Ballistic Products INC. BPI has an excellent master catalog and sends out sales flyers occasionally. The catalog has all kinds of shotshell loading tools that you might need. Some really neat tools for anything shotshell. Plus they have all kinds of shot, components, and other products.
