First let me start with some background on the subject.
I have been looking into buying a Glock in order to get into a more widely available platform so I decided on the Glock 33 as a BUG with 'power'. My other BUG's are KelTec P32 for deep concealment and a S&W 642 for everyday BUG. So I had my FFL order me a Glock 33OD with factory polymer sights. I had 4 main reasons for chosing the 33.
1) I have plenty of Range and Carry Ammo because as you will read below I all ready own two pistols chambered in .357SIG.
2) It would give me a BUG the same caliber as my carry weapon.
3) I am a 1911 guy at heart and have a Kimber Ultra CDPII that I carry on occasion and the "Pocket Rocket" would allow me to carry a highly effective round to compliment the .45ACP.
4) Any round that turns cover into concealment is tops in my book. (also the same reason I have a DPMS 7.62X51)

These are excerpts from two of my posts from previous threads involving the Glock 33.  

I have two S&W M&P's in .357sig one Full size and one Compact. I love the round and am looking into a G33 that is calling my name, but a nephew had a G19, I berlieve, many years ago that I shot and my only complaint was that the trigger safety pinched me every time I pulled the trigger. Luckily a new indoor range just opened near by that offers rentals and of course they have glocks for rent so I can see if the pinch is still a problem. As far as .357sig ammo it was the only widely available round during the 'ammo shortage'. I can buy 50 rounds of Speer Gold Dots from a semi local gunstore for $44.99.

Range Report Glock 26:
I was able to go to the indoor range this morning and rent their Glock 26. The Glock 26 really surprised me. I shot 10 rounds out of it to aquaint myself with the weapon. No finger pinch and my first shot went through the center X at approximately 25 feet. Then I went into comparison tests with the trigger pull and reset against both my M&P's 2 shots at a time. Glock 26, M&P 357C, then M&P 357 utill I had cycled through a magazine in each weapon. I was actually very happy with all three weapons trigger feel. I had been thinking of upgrading the sear in my M&P 357C to an Apex Duty/Carry but after this outing I reassured myself that I like the stock feel. So now I'm going to be putting that money towards a new OD Green Glock 33. All in all a good range trip 90 rounds of 357SIG and 50 Rounds 9MM and a $25 real world comparison test between pistols to determine if I should buy one.

Range Report Glock 33:
Went back to the indoor range and took my wife this time with the new Glock 33. Same as above I shot 9 rounds out of it to aquaint myself with the weapon. Still no finger pinch but my first shot was 3-4 inches to the left of the center X at approximately 25 feet as were the other 8 in the magazine. After about 90 rounds of Speer 100grain Frangibles and 18 Speer 125grain TMJ my groups were coming together but I had 3 failures to feed. I could have been limp wristing but have never had that problem ever in 18+ years of shooting semi-auto pistols or possibly the 100grain frangibles since none of the TMJ's caused this. I understand that this is a new weapon and some break in is required but I was so impressed with the Glock 26 rental that I am disappointe in my Glock 33. I don't consider it unreliable because I believe the failures were from the low powered target ammunition not the weapon. I also believe some of the accuracy could be from the ammunition as well, but I don't have the same issues with my M&P's with the same ammunition. All in all not a bad range trip but it could have been better could have been alot worse.

I guess a lot of people shoot the Glock left.  Not sure about the FTF.  Is this a Gen4 or 3?

Take your empty hand and pretend you have the Glock in it.  Now pull the trigger.

Does your finger end up at the base of your thumb?

Try again, but make sure the tip of your finger stops at the base of your trigger finger.  This should help with the shooting left.

Some other people say to rotate your hand in so you are putting more finger on the trigger.  I didn't want to change my grip so I did it my way.

I don't believe Glock has come out with the Gen 4 on the 33 yet I heard from my FFL that the Glock 31 is next. The test fire date on the test case envelope is 4-27-10. Mine does not have interchangeable back straps so no. As far as pulling to the left I didn't have that problem with the Glock 26 or any other pistols that I shoot. I was wonderig if anybody had problems with misaligned sights from the factory.

http://www.ar15.com/forums/topic.html?b=5&f=13&t=99034

Thanks I searched but came up empty then decided to post. My searchfu must be shooting left too.

We finally took advantage of the extra day this weekend to go to the local range. Took my Kimber Ultra CDP II, Glock 33OD, and the wife's KelTec P32.

Range Report:

Kimber: 51 rounds 235 Independence FMJ. tried and true no malfunctions, no flyers, and love the 3LB trigger (Note to self don't alternate target shooting a 1911,  Glock, and  KelTec).

KelTec P32: 21 rounds 73grain Georgia Arms. FMJ verrrrrrrrrrrrrrrry looooooooooooooooooong trigger. It has an armalaser attached due to the iron sights being off (no adjustment) and I watched my wife dance the little red dot around center mass like it was doing the tango. All in all she did well but this trip solidified my decision to get her into dare I say at least a 9mm. I let her shoot my Kimber and she almost dropped it on the first shot and handed it back and said you shoot this thing.

Glock 33OD: 50 rounds Speer 100grain Frangible. Fixed the shooting left by using more of my finger on the trigger. Shot good groupings. Had the slide lock back on all 4 still loaded mags. 2 factory 9 shot 33 mags and 2 factory 15 shot 31 mags. Slide locked to the rear on 6 different occasions. A simple release of the slide catch chambered the new round but this shouldn't have happened. This is the only pistol I have ever shot that has locked the slide to the rear on a loaded magazine. I have been shooting WWII 1911 since I was about 8, well used M9's for 6 years in the Army, new Kimber since 2008, and a new S&W M&P since 2008, My wife actually made the comment that I bought it at such a good price I could sell it or trade it and not loose money.

For those wondering it was test fired on 4/27/10 from Glock, received it 9AUG10, cleaned it twice (didn't remove the copper anti-sieze), and have shot about 100 rounds Speer 100grain Frangible through it in two range sessions. Used this same exact ammunition in both of my S&W M&P 357's with no malfunctions.

Next time you shoot take a look at where your thumb is in relation to the slide stop lever. "Riding" the lever during recoil is a pretty common cause of that problem.

Could well be that it doesn't like the ammo.  I'm guessing, but I bet if you called Glock they would say try a traditional load. I have 9mms and 45 acps that do not shoot frangible ammo reliably. Some guns do; some don't...especially when new. Shoot some full-powered FMJ or JHP ammo through it and try the frangible again when the round count is higher.

+1 lots of new Glock shooters have the same problem. Now go put 1k rounds through it and you will see a difference in your shooting. It amazes me how many people buy a new gun and fire it less then 500 rnds and sell it because they think its not reliable. I always see guys buying new guns and they usually buy a bunch of gear with it but they only buy a box of ammo. If its going to be a carry gun you should put atleast 500 rnds through it before you make any judgements and for me that is the low end. Keep this a secret because I love buying cheap guns especially Glocks that don't work.

I never said that I thought that the pistol was unreliable. In fact I said that 'I don't consider it unreliable because I believe the failures were from the low powered target ammunition not the weapon' I still believe that the issue is me not the weapon. After reading the last post I held the unloaded weapon in my hands as if I were shooting them and my thumbs were close to the slide lock. Closer than any other semi-auto that I currently own or have shot. I didn't have slide lock back with the G26 that I rented. That may be due to the added snappiness of the .357sig recoil.

If I would have wanted to get rid of the weapon I would have just sold it. I wouldn't have started a thread asking for advice from my peers on how to fix my problems.

Yes I would say that out of all of the pistols that I have shot new, used, or issued (with the exception of one M9 that I was issued that would shoot around corners) I am disappointed at my inability to be able to shoot this weapon straight out of the box without asking for pointers or as easily as the rental G26.

New Kimber Ultra CDP II 3" barrel supposedly the most problematic 1911: Open box, clean firearm, go to range, pound center of target appx 200 rounds.
Used S&W M&P 357: Open box, clean, range, pound center of target appx 150 rounds.
New S&W M&P 357C: Open box,clean, range, pound center of target appx 150 rounds.
New KelTec P32: Open box, clean, range, pound center of target appx 50 rounds.
New Glock 33OD: Open box,clean, range, pound left center of target, have slide lock back appx 50 rounds, start thread post on ARFCOM, take advice to put more finger on trigger, open box, clean, range,
                             pound center of target appx 100 rounds, slide locks back, update thread post on ARFCOM, take advice to pay attention to placement of thumbs to slide lock, grab weapon check out
                             advice, woah thumbs danger close to slide lock, ascertain that added recoil of .357SIG round could be culprit, make mental note to keep thumbs down.

I don't believe in this magical 500 round number. I do believe that anyone that carries a weapon for self-defense that they have never shot or cleaned is an idiot and gets what they deserve. I do believe the only thing that will make you better is practice and to practice you must send lead down range. But to put a number on that readiness is ridiculous. If you feel comfortable with a weapon it will be immediate. Trust is earned but at different rates.

Thanks for the help
After reading the last post I held the unloaded weapon in my hands as if I were shooting them and my thumbs were close to the slide lock. Closer than any other semi-auto that I currently own or have shot. I didn't have the slide lock back with the G26 that I rented. That may be due to the added snappiness of the .357sig's recoil.