I have a new Sight Mark .223 red laser bore sight coming from Amazon to get the iron sights and GTU scope on my Colt M4 Carbine dialed in once this laser bore sight is delivered.  When it is, I'll be able to see how well these batteries work and how long they last.  I have always gotten very good service from the Energizer alkaline, lithium and silver oxide batteries I have used in my battery-powered devices in the past, and expect to get similar service from these silver oxide batteries.  I have also not needed to replace the batteries of this type in any of my other existing battery-powered devices, yet, but when I do, I'll report on how these batteries perform for me.