Gun's wont shoot as full auto?

While I'm in a match my guns will fire full auto but once an enemy is on the screen and I attempted to shoot my gun trips out and will fire 1 or 2 shots then pause then 1 or 2 shots more rather than continuing to fire.

I already tried a clean install and that hasn't solved my issue. I'm not sure if anyone else experience this issue.

Any fixes?

Thanks in advance!