Commercial 1911s tend to be ammo sensitive. 1911s were designed in an age of hand-fitting. The military ones were very loose fit on purpose to increase reliability, but the fit also reduced accuracy. The process does not work as well when translated to modern machining. The most reliable 1911s are still all hand-fit, but are very expensive. The Nighthawk that I just wrote the article on is $3800. On the other hand, modern pistols such as the XD, S&W, Glocks, Sig, HK etc, don't seem to be ammo sensitive and are more reliable than most 1911s.