I have a Colt 1991A1, the gun has always had a problem with the accuracy going down hill as the gun heated up, 30 to 50 rounds fired. I installed a Wilson group gripper in it hoping to cure the problem, now when it heats up it jams on the first round of a full mag, I tried three different mags and the same thing. I installed a new recoil spring and shock buff kit at the same time as the group gripper. There is definataly something going on with heat and expansion somewhere, any ideas ?

Dump the gripper, and the shok buff, go back to stock parts and check the fit of the BBL bushing and lockup. What kind of ammo are you using? If it a soft swaged lead bullet it's probably stripping in the rifling and ruining accuracy.

Most of the accuracy stuff they sell you for a 1911 type gun are gimmicks. They will not make up for a poor lock up and tend to cause problems.

30 rounds will not heat up a 1911.

Does the gun shoot low and to the left the longer you shoot it?

[Does the gun shoot low and to the left the longer you shoot it?/quote]

YES ! that's exactly what it does.

Ammo is my own, 5 grains of Titegroup with Berry's 185 HBRN, but it does the same thing with factory ammo too.

By jamming I mean the first round on a full magazine will not chamber when you release the slide, it kind of goes half into the chamber and hangs up the slide.
But as I stated before the jamming part started after the group gripper, and only after about 30 rounds fired.

As for lube, I clean it and lube it with Breakfree CLP after every shooting event.

The jamming part is probably caused by the extractor. Replace it with a Wilson or Ed Brown and the problem will go away. Charles the Gunsmith.  

Have someone else shoot the pistol after you have run through enough rounds to have problems.
It sounds like trigger jerk and getting tired from recoil and limp wristing.

I think you've got two things going on here.  First is the accuracy issue.  The low left means you're probably getting fatigued as you are shooting and you're developing a flinch.  Most likely, when you start out, you're fresh and concentrating on what you're doing.  Check this by loading a couple of snap caps into your mags after you start noticing the accuracy degrading.  Since you reload, make yourself a few dummy rounds as they feed better than plastic caps.

The other problem is likely related to the shock buff.  I have a group gripper in one of my guns and its never caused a problem.  The shock buff on the other hand, causes no end of feed problems.  

So... before doing a lot of work, go back to the range with a handfull of dummy rounds and ditch the shock buff.  If that doesn't work, ditch the Group Gripper as well.  

I appreciate all the feed back from you guys but I can assure you I'm not flinching or getting "limp wristed" I have been shooting for close to 30 years and have many other firearms.

There is something going on after shooting a couple mags.

More info, last year when I was looking for a group gripper at a gun show a guy talked me into installing a longer barrel link, said it would do the same as the group gripper. After about 30 rounds it jammed worse than than it is jamming now, but worked fine with good accuracy for those first 30 or so rounds. Needless to say I put the stock link back in and the jamming went away but the accuracy would still deteriorate badly after 30 or so rounds.

Quoted: [Does the gun shoot low and to the left the longer you shoot it?/quote] YES ! that's exactly what it does. Ammo is my own, 5 grains of Titegroup with Berry's 185 HBRN, but it does the same thing with factory ammo too. By jamming I mean the first round on a full magazine will not chamber when you release the slide, it kind of goes half into the chamber and hangs up the slide. But as I stated before the jamming part started after the group gripper, and only after about 30 rounds fired. As for lube, I clean it and lube it with Breakfree CLP after every shooting event.

You are anticipating the recoil and trying to "beat" the gun. You end up jerking the trigger when this happens. I do the same thing when I shoot for too long a time without taking a break. I take a "smoke break" and go back to a .22 pistol. While you can't see it someone WATCHING you will. Shoot for 25 rounds and then work up 5 more at a time.

It is very common, and something you can train yourself not to do if you do it correctly.

I don't put fru fru on my 1911s anymore, but I will admit that for a time I "tried" all the new improved shit. I call it shit for a reason. Most guns are more accurate then the shooter is. Especially true for most of us.

If a GI 1911 ran for 100s of thousands of rounds before the frame gave out you don't need buffers and all that junk. A good recoil spring is a better investment anyways.

The military used to have a picture of groups and what was happening to cause them. size, vertical and horizontal, the works. I'll be damned if it was'ent the best pic I ever saw of groups/cause.

Quoted: [Does the gun shoot low and to the left the longer you shoot it?/quote] YES ! that's exactly what it does. Ammo is my own, 5 grains of Titegroup with Berry's 185 HBRN, but it does the same thing with factory ammo too. By jamming I mean the first round on a full magazine will not chamber when you release the slide, it kind of goes half into the chamber and hangs up the slide. But as I stated before the jamming part started after the group gripper, and only after about 30 rounds fired. As for lube, I clean it and lube it with Breakfree CLP after every shooting event.

Buffer ia not allowing the slide back far enough to properly pick up the round. When you fire it tho, the slide compresses the buffer some and allows it to feed properly.

Quoted: The military used to have a picture of groups and what was happening to cause them. size, vertical and horizontal, the works. I'll be damned if it was'ent the best pic I ever saw of groups/cause.

Do you mean something like these?

Right hand shooter.
http://www.ammoman.com/graphics/diagn_right.jpg
Left hand shooter.
http://www.ammoman.com/graphics/diagn_left.jpg

Ok, now that we have determined that I have some sort of shooting disability, although seems funny I don't have any problem shooting my buddies Sig P220, let's move on to the second problem.

If my gun function problems are because of the add-on's, group-gripper, shock buff kit, why does it only happen after 30 or so rounds? it shoots flawless when it's cold, let me repeat, the start of a new shooting day when the gun is cold it shoots flawlessly, after 30 rounds it jams on the first round of a full mag and accuracy goes to shit. Next day cold gun shoots like a dream for first 30 rounds, see where I'm going with this ? What the f**k could be expanding in there to cause these problems?

Quoted: If my gun function problems are because of the add-on's, group-gripper, shock buff kit, why does it only happen after 30 or so rounds?

It's easier to determine "where" the problem is than it is to figure out "why" a particular part is causing the problem.  

If it runs fine without a shock buff / group gripper, but pukes when it's installed, you have figured out "where."  You can then worry about "why" if you want to.

"...a guy talked me into installing a longer barrel link..."

Changing links without checking and making sure the extra length is required is not a good idea.
The barrel will move further into the slide, but is is now 'riding the link' instead of having the barrel feet ride on the slide stop shaft.
Assuming you have gone back to the original link, you should check the slide stop shaft to ensure it did not get bent.
A dial caliper's blades makes a good parallel surface for checking.