If you learn how to properly load them and then unload the cases without bending them they will last for years. There are tools available for loading moon clips. If they bend even a little you'll get light strikes and sometimes if severe enough it will bind the cylinder.

Anton, these are the same moonclip is used in IDPA, IPSC, Steel Challenge and ICORE competitions. These moon clip will last a long, long time Sir.

Anton, The moon clips will last until you lose them. They will not wear out.