One of the “benefits” of working on a SWAT team is a whole bunch time spent cleaning guns. Some days, we have plenty of time to clean, and others, we do a quick “combat-clean” before we load up for an Op. Truthfully, you can shoot most modern guns an awful lot before they have any issues. Depending on the condition, my cleaning might range from a wipe-down to complete detail. Here are a few areas on Glocks and AR15s that I always try to touch on: 

1. The breech face is the part of the gun where the back of the casing sits in the chamber, and there is a small hole there where the firing pin moves through to strike the primer. The breech face can accumulate carbon/debris and potentially affect the depth of the primer strike. Keep this area clean away to ensure a strong primer hit. In an AR-15, the firing pin extends through the back of the bolt and the inside of the bolt carrier, so those areas need to have that excess carbon scraped away, too.

2. Any of the parts that move considerably during the firing cycle, such as the grooves where the slide attaches to the frame of a pistol and the bolt carrier group in an AR-15, should get cleaned and lubricated enough to cycle smoothly. If it feels sticky or gritty, it needs lube and probably a good cleaning. Again, these weapons can take quite a bit of usage, but enough friction can prevent it from cycling completely. Range days and protracted gun battles might require extra lube, so plan accordingly.

3. While you don’t need to obsess over it, cleaning the bore of a handgun or AR-15 is still important. That said, my sniper friends say their fancy rifles shoot their best (that is to say, consistent and predictable) when they have been shot through and are a little bit on the dirty side. Run some wet and dry patches through it, brush it real good (your brush should fit fairly tight—if it’s easy to push through, it might be time to switch to a new one), then alternate wet and dry patches until they start coming out clean. It’s also a good idea to let some solvent sit in there a few minutes to work, just make sure you get it all out. 

Everyday carry guns face a range of other issues that also demand attention: Lint, moisture, springs under constant tension, wear-and-tear, etc., and those issues to be addressed separately. The lesson here is that there is some variance between what these weapons will tolerate, and what YOU tolerate, to guarantee they function reliably. Doesn’t have to be perfect—you can get away with a hasty cleaning, or even a skipped cleaning, every once in a while—just remember, you might be betting your life on it.