SBE2 cycling problem

[ffgats]

hi

hope to hear what you think is the issue

When shooting light load( 2 3/4, 2 /3/4 drams 1 1/8oz) Federal top gun, occasionally the fired case wont full eject even with a light recoil spring, so change my ammo to the same brand with the 3 drams, this time it extract and eject without problem, however experienced a failure to release a shell from the mag. the mag spring feels it has good push, could it be the carrier spring or the latch (cant remember the name)that activates by the trigger and activates the shell latch. Tried another box ( Challenger 3 drams and low brass same as Federal))of shell, everything went well. thanks