The best are A-Zoom , sold by Cabela's for under $20 usd! They are CNC turned, and look exactly like the live cartridge, only black! They are very good for checking feeding in a bolt rifle, and are the best for an ejector double rifle because they are abouth the same weight as the live cartridges! I have them for my 470NE, and my 9.3X74R doubles, two pairs each. The two paires are to practice dry-fireing, and quick re-loading og the next two rounds.