Frontier Gander,
For most BP guns, the practical limit of 2F powder that they can ignite with normal weight projectiles (under 500 or so grains) is around 130 +/- grains. Anything beyond thisends up adding weight to the overall load and not really contributing much to the velocity or pressure of the shot. Pelletized powders however can burn completely under such conditions most of the time. Also finer granule powders (3F, 4F) burn quicker due to the Higher weightfrom better compaction and increased surface area that is exposed to the flame for a given volume of powder. It's kind of like a jar of sand vs a jar of pebbles, The sand weighs more because you can fit more in the jar with less air space between the granules. I'm sure most everyone knows this but I thought it might help explain the differences in powder for those who may be new to the sport.

Pglasgow,
I will see if I can get that information if he knows for certain. Do note however that the comment was difficult, not impossible to blow one up. There is always the possibility of an unseen structural flaw as well as other unknown problems that can cause a bad day while shooting.

Indy,
I agree pretty much with your comments, especially the last one. The 53 cal mentioned in the above comment using 187gr of powder would be very close to equal with a 50cal and 150gr of powder, I base that on the 20% difference in the max listedload for my 54 and 50 of the same make and model. The difference in the powder strength howevermay not be as big as some would think. The mid 19th century has been claimed to be the hayday of BP development and the powder from that era was some of the best that has been produced up till now. I wouldexpect thatmodern powders are more consistent on a lot to lot basis but I doubt there was that much difference in strength on average. I could be wrong on this but that is the impression I've gotten from what I've read or learned from talking to more experienced and learned ML shooters.

For the record, all my comments are based on my own experiences and discussions with others and only constitute one mans opinion. I do not consider myself to be an all knowing BP guru, just someone with an interest in a fun and interesting sport called muzzleloading.

It's too bad we have taken this "Good Cheap ML" topic so far off topic. If folks want to continue this train of thought maybe someone could start a different thread. My appologies to the original poster for this diversion.