The only thing wrong with a Marlin Guide gun is that stupid hammer block safety. That thing can screw you.
1. Push the safety to the "Off" position. 2. Put a tight-fitting neopreme "O" ring in the groove for the red "Safety Off" indicator. 3. Forget about it
I have been doing this for years now on my Guide Gun and it's never failed me. It also doesn't permanently change the gun if you ever want to get rid of it.
