Oldpoop,
The 1911 is usually a very reliable gun when in spec, sounds like yours is not.
First if the hammer drops when the slide is released then the jar of the slide going into battery is causing the sear to slip our of the hammer notch. This is not a magazine issue but a fire control group adjustment issue. I have see this happen when a gun has a weak or poorly shaped tigger/sear spring (the flat one under the mainspring housing) or if it is not installed correctly or someone bent it too much. My first thought would be to get a wilson or wulff spring and replace it.
If this does not correct the issue then the angle of the sear and how it is engaging the hammer full cock notch is not correct. Correction of this issue should only be done by someone familar with 1911's. It may require actually replacing the sear and/or hammer.
As far as the safety it sounds like they use a two piece part where the safety is welded to the pin the goes thru the beavertail. or maybe they are using a cast piece and there was a flaw in the casting. In either case this failed and it happens. Seen it on colts and springfields on occassion also. Again this is a fitted part and even the "drop in no-gunsmiting" ones take a little hand fitting to "get them right". Again this is something that should be done by someone that is familar with working on 1911's.
Can an individual doe the above. Probably if they are careful. If you choose to do this I would suggest finding someone, one of your shooting buddies probably knows how, and have them there and show you how to detail strip the gun. Or at least have them standing by in case you need to take the box of parts over to them for help reassembling. I have put a number for these back together for folks that have taken them apart and then called to ask how many extra parts they should have left over.
I like to strip the gun and use the outside of the frame as a "jig" to first see how the fit of the sear to hammer notch is and go from there. Remember that you never use anything but a fine stone to touch up the surfaces, know the angles you need to acheive and remove very little metal or you will break thru the hardened surface and after about 25 rounds will have the same issue all over again as well as a varying trigger pull.
On the upside I have guns with issues like these and they just needed a good cleaning and oiling. You would be surprised the junk I have found in "brand new, just out of the box, straight from the factory" guns.
If it were mine and new, since Taurus has a lifetime warranty, I would send it back with a very detailed letter regarding Exactly what it is doing, that it is the second time back, it is a safety issue.
This is just my opinion based on my experience. I use to putter with these quite a bit in the late 80's and early 90's when I did a lot of IPSC shooting.
Good luck...
DonT
