[xmission]

The other primary cause of jams is an over-wound magazine latch spring that prevents magazines from being fully latched in. Especially on three shot burst, the mag works slightly loose and the later rounds may misfeed.

Most armorers think that the tighter the latch, the better. That's generally true except when you are in a firefight and swapping mags in a hurry, a softer latch will more likely allow the mag to bottom out and stay tight.

Just curious how this causes the mag from being fully latched in? Not doubting you, just wondering?

[gandalftb]

If the latch is stiff but you are careful to push the mag all the way home, no problem.

The problem is when your troops are stressed and changing mags quickly. Often they can't look at the side of the mag to see if it is fully home, but it feels solid as the latch has ridden tightly up the mag catch.

As the mag feeds out, the spring pushes hard and chambers most of the rounds. However, the last few rounds have less spring pressure, if the mag loosens, rounds may not feed all the way in, jamming.

A softer latch is easier to push the mag past, all the way home. That is why I prefer worn mag cases with new springs and only five turns on the latch spring instead of the standard eight.