Q: I like the Lee Enfield action with 10 shot magazine and wonder if it would be possible to convert one to .45-70? It would make a devastatingly effective gun for everything from pigs in lignum to sambar in brush.
A: Important factors in determining whether a conversion is feasible are the dimensions of the bolt face, action length and width of the side rails, together with the working pressure of the proposed cartridge by comparison with the original. Some people want to convert an action to a magnum cartridge that generates chamber pressures much higher than those for which the action was designed. This is can be dangerous, particularly if the action is a very old one. In the case of the
.303 British and .45-70 there is no problem because the .303 works at higher pressure. The rim diameter of the .45-70 is larger than the .303 - 0.608" against 0.540", but it shouldn't be difficult to modify the extractor to handle the 0.608" larger rim. Case length shouldn't pose any problems either since the .45-70 is just a bit shorter than the .303. The Lee Enfield magazine may need a little work to feed the fatter case, but a good gunsmith should be able to carry out the conversion without too much trouble.