i used it on a g21. i followed the instructions on the tube to the letter. after i dried the barrel with clean patches, i lubed it with clp. well, i guess i didn't completely get the stuff all out, although the patches came out dry. 5 days later i dried the barrel before shooting and happened to look in there, and that thing was pitted from the throat to the end of the barrel. with the clp on top of the blue wonder, the barrel underneath was not protected and pitted. so, no the shit sucks. i called novumsolutions, and they told me it was my fault. i ask how that could be since i followed their instructions. their reply was i should have went to novums website for special product instructions. it didn't say anything about this on the tube. ofcourse they wouldn't replace the barrel because it was my fault for following their instructions. go figure. i had to replace my own barrel for $130.00. i really don't care about the money but they should have made it right since the directions on the tube are bogus.