I have a AO ZG51 topend on a std. 1911a1 frame. The slide will not go back far enough to lock open breech or even back far enough to get behind a live round to chamber to it! I removed the recoil spring and the guide and slide goes back like it should. I also noticed that because this shorter slide assembly uses a inner and outer recoil spring, I am not able to install both and be able to compress enough for installation. I can't remember if I got the guide when I ordered the other AO ZG51 Pitbull parts or if I just took a std 1911a1 guide and used it. Is there a difference in overall length between the std. and the commander/officers recoil spring guide?? I am also in need of a AO ZG51 Pitbull owners manual, a copy or a scan to .PDF file woulde be great! Thanks for any help in advance!

Assuming the slide of your pistol looks something like this one:

(found in search engine)

If I am reading your post correctly, instead of using a compact/officers/commander size frame, you've mated your Pit-Bull slide to a full-size gov. model frame.

This is "no" working and possibly dangerous thing to do as these pieces were NOT designed for each other. Suggest ya get the proper frame for the slide or the proper slide for your frame. The parts are made differently for a reason and yes their is a difference in the overall length of a commander/officers/compact recoil spring guide and a full-sized one.

Just because both slide and frame are based of a 1911 design, that does not mean you can slap two different "sized" designs together.

Here's ya a spot to pick a manual from Auto Ordinance's web-site, www.auto-ordnance.com/ao_1911pkz_f.html, hope it helps.

Mike

PS - I've yet to see a gun manufactuer that will not be happy to send ya a copy of a manual for one of their products, suggest ya contact Auto-Ord if link above doesn't do it for ya.

Mr. Wilson I'm curious as to what exactly is dangerous about mating a compact slide to a fullsized frame? The ZG51 pic you found has a identical frame atleast in length to mine except mine is a alum. alloy frame. The dust cover of mine even comes to the same place towards the end of the slide just like the pic shows. That pic also suggest to me that the frame has a fullsized frame grip area. ??? It doesn't look like the grip area length in the pic of a commander/officer frame. ??? Any Ideas of where to obtain a new commander frame? Any other makers other than colt? I am not challenging your reply just curious as to what,when,why,where!

mjacvn71, if your frame is the same size as the pic I posted, then it is not as you stated in your original post "a std. 1911a1 frame" and my comments do not apply. There are several makers of full grip size commander and officers frames, not to be confused with as I stated here with "If I am reading your post correctly, instead of using a compact/officers/commander size frame, you've mated your Pit-Bull slide to a full-size gov. model frame.".

Suggest you take Kurt's suggestion and suspect you'll get your Pit-Bull working. Sorry for the confusion but Goverment model frames or "std. 1911A1 frame" are not compatible with the shorter commander, officers and compact versions and from your post seemed that was what you were attempting. All manufacturers of both full sized "Government models" and smaller "commanders, officers and compact place taller ejectors in the smallers version to preclude swapping of slides between the shorter  and longer versions.

As to the reasoning behind this I believe it has to do with the timing sequence and the precluding of the weapon from firing out-of battery which I suspect could happen, not a good thing.

Mike