The MkIII (1910) is the strongest action, but the only one that can be assembled incorrectly. Study the details on this site. Civilian models are rarer than military, but do exist. If you find a very early MkII or a MkI, have the bore diameter checked, as some of these have undersize bores. If you find a 1910 chambered in .280 Ross it will be difficult to find ammunition for it. There are a lot of cut-down MkIIIs around. These are fine for shooting, but not of too much interest to collectors. A cut-down MkIII in .303 is a cheap way to get started. However, once the bug bites you, you will want MORE!