I am a fan of the small Martini action, but it does have some limitations. Regarding a safety, the various add on safeties work, subject to individual fitting. The rifles will not fire if the underlever is slightly open, but spring tension keeps it closed enough that centerfire cartridges won't fall out( rimfire might). There are rimless extractor conversions, but single shots " belong to be chambered for a rimmed cartridge", to quote an old friend who is gone now. The actions are limited as to overall cartridge length, really a combination of OAL, diameter, and taper. For some "blown out" cartridges on 30-30 cases, it helps to turn rim diameter to .468" or less( but more than .422").The little German 5.6x50R is a great case for the cadet action. They often need firing pin bushings, however.
Mike