Ross Magazine/Feeding Issues

[nijalninja]

G'day there, I've got a MKIII (I think) that I have been using to practice for target shooting, in the hopes of using it in military rifle competitions, but it has an issue with feeding rounds up from the mag and into the chamber. What happens is the little ribs springs that sit over the cartridges in the mag and that guide them up and into the seat of the bolt-head seem to release them early, causing the rims of the shells to end up not quite where they should and spearing the cartridge off to the right. This makes the projectiles butt up against the surface beside the entrance to the chamber.

This seems to happen no matter what orientation you load the rounds into the mag, how slow or fast you close the bolt, what cartridges you use, or even how many times you depress the cartridges in the mag to let them align themselves. You can have one come up and spear off, take it out, put it back in the mag and it will not do it again, but the very next round will do the same thing. It also seems to be completely random, except that the last round rarely does it.

This problems seems to have started after the previous accidentally clamped the magazine, causing the platform to catch on its way up and down. We have spent some time with the mag apart, tapping various places on the housing to find some kind of 'sweet-spot' that will stop the problem, but its so damn finnicky we can't see any structured way to go at it other than praying we get it right by luck.

Now has anyone had a similar issue and had any luck fixing it? Ross parts seem as common as a one ended stick so getting a new mag is pretty unlikely, and even then I feel it might produce the same problem. Cheers.

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[RCS]

Attachment 90530I have a photo of 1) 303 Service cartridge 2) 280 Ross and 375/303 cartridge all for comparison as to length

[browningautorifle]

accidentally clamped the magazine

Then it took a squeeze, have you used a straight edge to see where it's bowed in?

[nijalninja]

BAR you are right, it did take a squeeze, and no I didn't think to use a straight edge. Thanks.

[mr.e moose]

I have seen this before when someone has the bright idea of clamping a M-10 mag in a vice to hold the rifle to work on it. The cartridge retaining clips are on the outside of the mag and when the magazine becomes dished in it opens up the feed lips so they do not hold the rounds.
All you can do is try to make a dolly and straighten the mag body out. Use a straight edge like Jim suggests to see how you are doing.

[nijalninja]

Moose, can I ask what you mean by a dolly? The clips getting bent would explain that, but I thought they might be a little more springy than that. If its just the clips and not the mag case then this might be a bit easier.

[browningautorifle]

what you mean by a dolly?

More commonly referred to as a thing...

[mr.e moose]

A dolly is like a auto body mans tool that acts as a backup on the other side of a piece of sheet metal to help you form it. If your magazine is crushed you will need to reform it back to it's original shape. Be careful on how you hit the magazine, it doesn't take much to distort and stretch the metal.

If you look at the cartridge feed lips on a Mk 3 they are retained by a hook at the bottom of the mag and for lack of a better word a dove tail towards the receiver. Remove the trigger guard by removing the bolt from the rifle to access the rear trigger guard screw and unscrew that along with the front trigger guard screw in front of the magazine. The trigger guard along with the magazine should now come free.

If the mag is not too distorted you should be able to remove it from the trigger guard. Sometimes it can be a b!tch. Once you get it out, carefully pry up the hooks at the bottom of the feed lips and push them up towards the top of the mag until they release from the dove tails and remove them.

They are made from spring steel so they should not deform. Using a straight edge check your magazine, it should be flat front to back and top to bottom.