Empty mag will not lock slide

[MartyK2500]

Hey guys, need a bit of input here. Sorry if i sometimes lack proper words as i am french + new to firearms.

The firearm we are talking about here is an svt-40. When i shoot the last bullet in my mag, the slide does not lock back. At first i tought it was the gas setting, i even dialed it up to 1.5 . Just to realize, that the small ''stopper'' that hold the bolt back, does not stay up.

I just fiddled with this tonight with an empty mag. When mag is freshly inserted and i pull the slide back it locks in place 4 times out of 5. But then only shaking the mag and/or firearm a bit brings the ''stopper'' back down and slide slams closed.

Any input? Picture with ''stopper'' circled in red.

 

[mr.664]

how long have you had this gun for?, have you completely disassembled the gun, and clean all that packing grease out of it with solvent blow it off with air, and re oil?

 

[MartyK2500]

I have had this firearm for 1 week now. I have completely dissassembled it twice now (one time when i had freshly got it, and once after an after-noon of shooting). I used the tip my firearms dealer gave me, wich is :

completely dissassembling it, spray a generous amount of brake cleaner anywhere you can, wipe off exess, use a reasonable amount of G96 gun oil on all metal parts, clean off exess, pass a bore snake in the barrel (wich also had some brake cleaner and oil in it)

I threat my sks the same way and some 1500 rnds later she stills shine real nice and working nice.