TBH, Congrats getting that Appollo. It' s been awhile since I saw that Appollo I owned for a short time I can' t remember how it was set up.I couldn' t tell you if it was a bolt or you pulled the pin back on a slide.Once it' s closed it should be very little chance of water entering. If you have a big gap there something doesn' t sound right.I' m assuming you have fired it.If it fires apparently the bolt is in the correct position.I wish I could help you more but without looking at one it' s hard to say . That Appollo I had I never fired ,so I' m really not much help to you.CVA is only a phone call away. They have excellent customer service.
Ruger Redhawk