Land_Owner, I hope you can get to the bottom of this. It's always somewhat unnerving not knowing what to expect when you pull the trigger.
First if I may, what you are experiencing is "doubling". Double tapping is an often desirable self defense and combat technique and it can be a lifesaver while doubling is, as you know, just plan undesirable at any time.
When an auto-loading pistol cycles the designer intended for the grip frame to be held relatively solidly and stationary so that the energy of the fired shot could cycle the slide and perform the steps of unlocking (if appropriate), extracting, ejecting, cocking, feeding, chambering and (where appropriate) locking.
If a shooter has a relatively soft grip and stance due to loose wrists, unlocked and unsupported elbows or, in some cases, a flaw in the actual grip on the pistol the flip of the pistol in recoil uses so much energy moving the entire pistol and your arms that insufficient energy is available for the action to cycle properly. This is aggravated by pistols with fairly high bore lines and heavy recoiling masses-which the M1911 has.
All this is why a soft grip and stance (AKA limp wristing) will usually present itself as a failure to feed or eject. In "stove piping" the extractor tilts the case towards the ejection port but the slide does not retract far enough to kick the case free so it get pushed forward until it is trapped and stands up like a stove pipe. With a failure to feed the case got ejected but the slide didn't retract far enough to strip another round out of the magazine.
I have match tuned a lot of M1911A1 pistols and tightened up a lot of them for special duties back in the bad old days before the Army just let us buy tight pistols "off the shelf". Without your pistol in hand and without knowing you gunsmith it would be useless to speculate on any possible mechanical cause. There are very few things that would cause the pistol to double. They are generally well know and fairly easy to check so I suspect that your gun plumber has checked them. It is worth noting that anything mechanical that would allow the pistol to double would also allow it to be fully automatic. If there are still rounds in the chamber or magazine after a double then the pistol is very unlikely to be at fault.
In your case it is possible that your grip or some other technique at the point of firing is allowing the frame to recoil away from your trigger finger and when the slide runs forward to battery the inertia of the slide pushed the frame (and the trigger) back into your trigger finger.
My experience has been that two of the more common reasons for this are that:
For all of our gun handling lives we've had the mantra of "Keep your finger off the trigger unless you are in the act of shooting" pounded into us. Even though the shooter is, in fact, in the act of shooting while the pistol is recoiling a lot of shooters tend to fling their trigger finger forward a bit as soon as they feel the trigger break. If the shooter does not fling it far enough the finger is sometimes going to hit the trigger during counter-recoil.
The other common reason is that if a shooter's wrists are not being held pretty firmly the pistol will flip up and rotate around the top of the shooters palm or the pivot point of the wrist. Either case can move the frame out of position and result in trigger finger contact on counter-recoil.
I am somewhat hesitant to give any advice on grip and stance without being with you and observing you shoot. Assuming that a "limp wrist" is the root cause of the doubling, too many of the possible causes tend to be interrelated and so they cannot usually be truly fixed without changing more than one thing.
With that said, the easiest way to affirm that the pistol is operating correctly and that the issue has to do with the shooter is similar to one already suggested. Load some three round magazines. With the pistol pointed at a safe backstop concentrate on pulling and holding the trigger fully rearward and keep it there. If need be, just mash it to make sure. After the first shot and when the pistol has settled down from recoil maintain your grip with the other three fingers and slowly release the trigger until you feel the trigger reset. Now, concentrate on the weight of the trigger pull and pull it rearward and hold it fully to the rear. Repeat that cycle-slowly release until set and pull the trigger back for the third shot.
Did it double? If not, repeat the exercise several times. That should confirm or deny whether the pistol is functioning properly or whether your grip may need work. They reason for the three round magazine is so that you can get an idea if the pistol is mechanically sound while if it does double or fire a burst you won't wind up sending the last few shots over the backstop.
What you are feeling when you only just set the trigger is the second stage of the trigger and on most M911s it is less than two pounds. Notice also how short the amount of trigger travel is between setting the trigger and releasing it. You can see why a loose grip or a trigger finger flopping around in front of the trigger can cause problems.
I am a retired Master Marksmanship Trainer, longtime bullseye and combat marksmanship shooter and coach, yadda, yadda, yadda, BS, BS, BS, ad nauseum. I'd be glad to talk or PM about your grip if you think that would help.
Good luck
Lance
PS: I should have asked. is the gun new or new to you? If it is new, have you had experience with similar pistols and loads?
