Cartridges

There are many, many, many different sorts of cartidges! They're defind by their gauge size (12 bore cartridge for a 12 bore gun), the size and number of pellets contained (No 8 shot contains about 410 small lead pellets per ounce, No 5 shot about 170) and also the total weight of the load.

Clay shooters might go for something like a 12 bore, No 8, 24g cartridge, whereas pigeon shooters might use bigger pellets such as a 12 bore, No 5, 28g cartridge. There are also high velocity loads which can be used with lighter shot.

In theory, more pellets means a better chance of hitting a target - choosing the wrong cartridge is a favourite excuse to be used on a bad shooting day.

You're best bet is to take advice from your fellow guns or local gun dealer.