i have tried to put a box through my newly acquired, slightly used glock 29. the extractor has been grabbing the empty brass, and holding onto it. the gun jams, as it tries to feed the empty shell.
i took it back to the gunsmith. he fired 40 rounds though it. no failures...
he says it could be due to me not supporting the gun strong enough to let it complete its cycle. hmmm, i dont think it is because i am not supporting the gun enough. i used a 2 hand weaver. i shoot my .45 with no problems (ever!), and i dont think the recoil is really that bad on the 29. i am about twice the size of the guy who successfully shot it.
well, i brought it home and stuffed a full clip in. the 3rd round stuck in the extractor...wtf? anyone have a clue?

btw, the gunsmith examined the extractor. he said it is working properly...

Even though you have no problems with the .45, the "dynamics" of how the guns operate are a little different between the two pistols. Felt recoil is subjective, but the fact is that the Glock's short, fast slide action requires that you "lock" the wrist...which really has little to do with how big or strong you are...and is not quite so much of an issue with your .45.

The semiauto requires a rigid platform in order to operate correctly. Consider if we were to somehow suspend your loaded G29 in midair using strings attached to the ceiling, and made it fire....what happens? The pistol fails to completely extract/eject the fired case, because there is no support for the frame...nothing to keep it in place while the slide does its' work...which means that the frame and slide move too far to the rear together for the action to work properly. (True, they must travel a very short distance together, but only until the bullet is out of the barrel and the pressure has dropped sufficiently) This support is particularly critical with a small pistol with a short slide using a powerful cartridge, such as the G29.

My guess...since we cannot see exactly what is happening...is that you are "breaking" your wrist just enough for this to happen ocassionally...most probably you will see this after a few rounds are fired without a problem because you are relaxing your support or shifting your grip under recoil and don't realize it. Try and imagine that you have injected "Super Glue" into your wrist with your hand in correct firing position...no up and down or side to side movement at all...it is locked solid...recoil comes straight to the rear, and the slide is the only thing moving. Try this and see if it doesn't help.

thanks for the very informative reply Ikor! (see if this sounds like a feasible explanation...)

i called glock, and explained the situation to the guy at the tech line. he offered to check, and repair the gun for free, if there was something wrong with it. they have very GOOD customer service! he also said he has seen hundreds of cases where the shooter was either breaking his wrist, OR pushing down on the gun during recoil. he said with a heavy slide like the 29, it is critical to not slow the slide cycle down, or it will malfunction.
i had a shooter come over tonight and watch me shoot a box. he said i was not breaking my wrist, but i was trying to force the nose of the gun down (which the glock guy said was a no-no). i finally got off a few mags without problems, by easing up on my death grip.
for now, i am going back to my 1911. it fits my hand better, and my accuracy is much better than with the glock (i am used to a minimum of trigger pull and travel). i may trade the glock, or i will get some experience with it this summer... and try it again.

Not sure about pushing "down" on the gun during firing...I have seen some shooters who will inadvertantly push against the slide with the weak thumb, which would slow the slide down, for sure, and certainly could cause this. When I shoot a Glock, I find that I do better if I use more finger on the trigger, similar to shooting a DA revolver, and sort of "oooch" it off of the sear rather than try and shoot it like a 1911. Try that and see if you don't get batter results. Also, remember that you only need to allow the trigger to return forward far enough to reset the sear...not all the way. You can feel and hear this with an EMPTY gun by pulling the trigger and holding it back while you cycle the slide, then s l o w l y let the trigger come forward until you hear a little "click"...now you are ready to fire again. Hope that helps a little.

Go over to Glocktalk...this is a known issue amongst 29 owners.  I had to send mine back to Georgia and they still haven't gotten it right.  One guy took a pair of pliers to his ejector and bent it upwards a little...he claims its a cure as do others.  I shoot my 29 back to back with my 30  (.45 +p) I never have any problems with my 30..That's why its my carry...the 29 will have an FTE about 1 round per 100.

thanks for the replies guys!
i liked a lot of the ideas that went into the glock pistols. it seems like a very good set-up for a safe carry gun. BUT... it is just not for me. if i spent "many" hours practicing with it, im sure i could become comfortable with it.
however, i am at ease with a 1911 in my hand. i "know" where everything is, what everything does, and what to do (by reflex)if something unexpected happens (such as a malfunction or whatever). i feel the 18 years of handling a single action pistol would pay off, if it were ever actually needed.
i traded the glock for a new springfield micro-compact .45acp
thanks again for the help guys!