You should be able to tell from looking at them if they need replacing. If you have not been snapping them without a cap, they generally don't go bad. I am assuming by your question that you don't remove them when you clean the firearm after shooting. You should always do that. You need a nipple wrench of the correct size for your gun. They just unscrew. I would try cleaning them good first, pipe cleaners work really well. Put a screen in your sink in case you drop it and with a pipe cleaner swab out the inside under hot running water. You will need to dry them good (another pipe cleaner). Hold them up to a light and you should see it shining through the hole. I usually put a light coat of oil on a clean pipe cleaner and swab one more time before putting it up. If they need replacing you will be able to tell by looking at the end where the hammer strikes and see if it has been flattened down. That doesn't sound like the case since you are still getting caps on them. Like I started off, unless you have been dry firing the gun without caps, they last a long time. I have two Colts that are over 25 years old and still have the original nipples. You can buy new nipples from a vendor such as Dixie Gun Works or go straight to VTI gun parts for most guns.
Last edited by PRM; 10-16-2007 at 06:05 PM.