So I bought a .357 Magnum Martini Cadet that was rechambered from the original .310 Cadet Caliber. That being said my state requires 1200 lb•ft or more of muzzle energy to use for Deer Hunting. I bought some Buffalo Bore Ammo 180gr Hard Cast Outdoorsman that when I emailed them they said that in there tests out of a rifle with an 18.5" barrel made almost 1600 lb•ft of energy. I told them my barrel was 25" and they said the ammo should make around 1400 lb•ft of energy at the muzzle which is over the state limit. They also told me the Hard Cast would do better in my barrel length then their Hollow Point 180gr .357 would. I bought the ammo and went to a local gun club that has testing equipment like chronographs. I shot 5 rounds through the chronograph at a target 50 yards away. The rifle grouped great but the measurement was not what was stated by Buffalo Bore. The fastest bullet to leave the barrel was the third shot at 1,825fps. The median fps was 1,757, calculated made the median lb•ft measurement out to be 761.12 lb•ft and the highest measurement was 790.57 lb•ft. Definitely was bummed out that the ammo didnt live up to what they told me to expect. I emailed them and they are going to send out another batch of 20 rounds. I fired 5 more rounds and out of a total of 10 the measurements stayed practically the same. Some of the old guys at the club said .357 Magnum will never live up to the state regulations so I should get a bigger rifle. I will wait for the next 20 rounds to come in and try again. Kinda bummed cause it was $60 with shipping and taxes for 20 rounds, I was told I would be reimbursed if the next 20 rounds dont live up to what they stand by. With all that being said one old guy who was helping me with the chronograph test said his father bought and .357 Cadet in 2002 and had it rechambered for .357 Super Mag by having the barrel reamed. Is that all that is needed to make the rifle .357 Super Magnum ? He did tell me .357 Maximum requires a whole new barrel and breech. Thanks for any replies, also could there be something wrong with my rifle that could be causing the bullets to travel so slow ? Buffalo Bore said I should expect to get around 2000fps with a 25" barrel. Thanks for all replies and any suggestions/advice. I guess I will be using my flintlock for the rest of the season or unless this new batch of bullets has an improved performance.