There is only one design of clip for all the M91 series Carcanos (M91, M38, M91/41 etc). And they come in brass or lacquered steel. It doesn't matter which you use, and there are no model-specific clips. In fact, if you find some 7.35 ammo, the clips are also the same. Likewise the ammo is the same for all 6.5mm models. The trouble comes from the bullets used by modern manufacturers. Search around the forum for the topics "Carcano ammo" and "Carcano reloading".