Just to inject a note of realism in here for a minute.
The Nagant cartridge interruptor prevents rim-over-rim jams but you have to USE it the way it was designed. This means that rounds must be pushed DOWN into the magazine far enough for the cartridges to be held by the interruptor. Push them down far enough that you can FEEL or HEAR the interruptor catch them. If you shove too far, no matter: cycle the bolt completely once and a round will pop up into feed position. You MUST cycle the bolt COMPLETELY: the interruptor is actuated by the bolt being turned fully into LOCK position. Do it slowly some time and you will HEAR the interruptor release the cartridge.
If you don't believe me, take the rifle apart and quietly ANALYSE what is going on. Black magic it is not; what it IS is darned good design. Emile and Leon earned their royalty money.
Best way to load the CHARGERS is with the outermost rounds flat against the back of the charger, the inner rounds standing on their rims and the innermost round standing on the rims of the inner rounds. From the side it looks like a pyramid: _-!-_. Do it like this and your chargers will work quickly and cleanly and they will do it every time. This is not MY way of doing this. Rather, it is the IMPERIAL RUSSIAN ARMY's way of doing it. They just might know a few things about thes rifles. For confirmation, see Plate LXII, facing Page 192 of the TEXT BOOK OF SMALL ARMS - 1909, put out by His Most Brittanic Majesty King Edward VII's Stationery Office in that same year.
Moisin-Nagant CHARGERS are available from Trade-Ex at $4 for a box of 5. My latest 15 arrived today and will do for a while, so you can order some now!
Moisin-Nagant rifles cannot be 'gentled'. They were designed and made to be worked positively, almost harshly. Keep the screws tight, operate the rifle as designed and it WILL work, right down to 50 below. You can't say that for very many rifles of ANY type.
Hope this helps.
.