I have a Ruger Black Mamba that I use for Steel Challenge Matches. It's a great pistol and I shoot it a lot. Over 75k rounds through it and I think I take good care of it, cleaning after every match or shooting session, about 500 rounds per outing. At the last Steel Challenge I had a number of failures. Magazines and bolt were swapped and still no luck so I pulled out my back-up to be able to finish the match. Since they are so similar the Match Director had no problems with my switch. Going to clean it I found a small piece of metal from the Volquartsen LLV 4 upper had broken off. I called VQ on Monday, Tuesday they sent me a return label for UPS. On the following Tuesday I had my gun back all repaired with a new LLV upper and new barrel installed. Great Customer Service from Volquartsen. Now I'm ready to shoot our next Steel Challenge match this Sunday. I shot it today with 400 rounds of Federal 525 pack of 36 grain plated bullets. Not one failure using 10 different magazines so I think it will work Sunday. I did have a variety of problems over the last few month so I'm guessing the part had been breaking for a while. I always take my Mark IV 22/45 Lite with me as a Back-Up and it pays off occationally.