How often should I clean my firearms? We get asked this question a lot. There is not just a simple answer. Most manufacturers recommend cleaning your firearm after each use. As I've said before, those of us at Def Comp, shoot often. My theory on gun cleaning differs for each platform of firearms. I put approximately 500-600 rounds through my personal pistols before I break them down and give them a bath. That number will not work with my 3-Gun shotgun. The Benelli M4 likes frequent baths and runs way better if the number is around 250 empty hulls on the range. EDC, or everyday day carry, guns will require cleaning every couple of months; even if you have not shot them. EDC firearms are subject to lint, sweat, dust and the occasional food particle depending on your preferred location of carry.
Another thought- Most people tend to over oil their firearms. This can cause issues and allow more of the above mentioned "lint and friends" to collect on the oil. Today's firearms are designed to function properly with just one or two drops of oil. I like to put a drop of oil on a Q-Tip and then rub the Q-Tip on the contact point. I have far more control over where the oil goes verses trying to just drop a bit of oil onto contact parts. With your firearm taken apart, look at contact points to see where you should oil the firearm. The "ears" on the frame that the slide moves back and fourth on is a good oil location and you should be able to visually notice the contact points to see where you should oil. Remember, take on the less is more theory.
Carbines can drift off into the 500 round number as well, but I usually put a drop or two of oil on the bolt every couple hundred rounds just to keep it functioning flawlessly. I personally do not have a favorite oil or solvent that I prefer. Between Shot Show in Las Vegas each year; the matches, training or conferences we attend; or, clubs or leagues we belong to, we pick up several "goodie" bags of oils, solvents, brushes, jags, and patches. The new big thing in gun cleaning is water soluble liquids. They are effective and have little or no odor. I still recommend wearing gloves to clean your firearm, due to the powder and lead residue that merry with certain areas and parts of the firearms.
Getting back to the number of rounds before cleaning - If you are having failure to feed issues or out of battery problems, then I would do a fast field strip, wipe down and oil while on the range and a full cleaning after the range. That is your gun telling you it's armpits stink and it is time for a makeover.