Auto-loaders and rimmed cartridges

[Anteater1717]

Why are auto-loaders chambered for rimed cartridges regarded as less reliable than auto-loaders chambered for non rimed cartridges?

The reason why I ask is because I can think of more than a few auto loading center fire rifles that fire rimed cartridges reliably. The Ruger Deerfield carbine, the SVT-40, and the AVS-36, don’t have a bad reputation’s. Yet whenever someone talks about making an auto-loader in a rimmed cartridge the reliability of that rifle is brought into question.

 

[hksw]

With a rimmed cartridge, you introduce one additional potential of unreliability as compared to a rimless cartridge. If the rim of the cartridge above is somehow either loaded incorrrectly or under recoil jumps the rim of the cartridge below so that is is behind it, it could lead to a feeding problem as the top cartridge is hung up by the rim of the cartridge below. Never seen happen but theoretically can be done. I have loaded 7.62X54R so that the top cartridge rim was behind the one below on purpose to see the problem first hand on my M44 and it certainly did hang up.

 

[Jeremy2171]

I have loaded 7.62X54R so that the top cartridge rim was behind the one below on purpose to see the problem first hand on my M44 and it certainly did hang up.

Then that means your rifle is NOT functioning correctly. The Mosin-Nagant design includes an ingenious feature.... The interuptor-ejector..it actually holds down the 2nd round in the mag allowing the top round to feed without hanging up on the rim.

On every new MN I buy I "stack" the rims behind each other to induce the jam. If they jam then I troubleshoot the problem....sometimes the stock is binding up the I-E and needs a little shave, one time the receiver was bent pinching the I-E so it would hardly move...I tweaked it a tad and it works smooth as glass.....


If it jams with a "rim jam" you need to look hard at the parts and see where the problem is located....