My colts and kimber have not misfired or jammed.. if in another gun, there was a misfire or fail to feed stovepipe I have usually also seen a weak hand hold or something dragging on the slide, or a burr of some sort on the feeding ramp... but never on one of mine and never many ever anywhere ... some folks experience is different... we all have favorites and confidence in them... I would never just choose a brand and assume that gun will work for me or take that for granted...not for self defense.
I think sig is also very good... but I have not had any problems with any 1911 styled semi in 40, 45 380 9mm 38 super... different types, etc. but I do keep them clean if it is a tight really tight gun and requires that... I would not hesitate to use any brand of 1911 clone, and get a knowlegeable smith to check it out AFTER I shoot several hundred times to break it in... I beleive in the design and it is pretty simple for a decent smith to get it just right... a mil spec 1911 will not jam and will not stove pipe, I would bet on that... it is not as accurate either as the tighter ones.. for defense I like reliability... my kimber is about 12 or 13 years old and has been shot a whole lot; it started its career as a police service weapon; and has a good bit of wear on it, and it is better than a new tighter one, at least to me.
I do stick to ammo that is similar in shape and weight to the 230 grain round nose fmj most of the time...but occasionally lighter loads always functioned just fine...
were the non-functioning guns well broken in, etc ? I always shoot a bunch of fmj bullets through any new semi and check it for any rough spots, and clean it really well before I rely on it... dk