TM NGRS continues to shoot after empty magazine trips bolt catch

[hitmanNo2]

I have a TM NGRS M4 that continues to shoot despite an empty mag tripping the bolt catch.  All my mag springs seem fine, they immediately pop the bolt catch on empty.  However, even with bolt catch activated, it will still fire.

It has a BTC Spectre Mosfet fitted.  Is this likely to be the culprit?  Does a sensor on it replace some factory function?  I thought it was a 100% mechanical system.  Is that not the case? 

Any ideas?

 

[Speedbird_666]

I am no NGRS expert - but there is a switch on the BTC Spectre board for what appears to be the bolt stop mechanism.

View attachment 139739

I would also refer to this video with regards to how the mechanism works in the GB with the BTC Mosfet:

 

[hitmanNo2]

Ah.  Thanks.  I'll check that out.