Why Does Kimber Trigger Pull Change

I have a Kimber Custom II .45 cal. and the trigger weight varies. If I cock the hammer and pull the trigger it is about 3.5 lbs. If I hold the trigger back and drop the slide and shoot from the reset position, the weight is still about 3.5 lbs. The thing that puzzles me is that if I drop the slide without holding the trigger, then pull the trigger, it jumps to about 5 lbs. Does anyone have an idea what is happening?

The only time that has ever happened to me was when I over-tightened the grip screws and put the frame in a bind. It turns out the magazine release was staying partially engaged and the trigger was dragging on the mag release. The trigger would also not re-set sometimes. I finally figure out what was causing the problem and the pistol has run flawless since then. You may have a similar or totally different problem. And I have no idea why tightening the grips caused the release to bind.

Len

I've had two wad guns built on Kimbers and both had problems similar to what Len describes. One fix was to shorten the grip screws by about one turn.  I've checked the trigger pull numerous times on both, by cocking and by dropping the slide.  3.5 lbs every time.

OldMaster66 wrote:The only time that has ever happened to me was when I over-tightened the grip screws and put the frame in a bind. It turns out the magazine release was staying partially engaged and the trigger was dragging on the mag release. The trigger would also not re-set sometimes. I finally figure out what was causing the problem and the pistol has run flawless since then. You may have a similar or totally different problem. And I have no idea why tightening the grips caused the release to bind.

Len

Wow excellent, I have a similar problem with a pistol that built by one of the top smiths in the county I try shortening up the screws.

Instead of shorting my grip screws I just ordered a bunch of those little rubber bands that go on the screws and put them on all my 1911s.

Len

 cheap fix

http://www.ebay.com/itm/MIL-SPEC-12-Grip-Screws-O-rings-1911-Colt-Sig-Remington-Ruger-Kimber-Smith-CZ-FN-/222129570770?hash=item33b7f443d2:g:33QAAOSwhOBXUFOr

OldMaster66 wrote:Instead of shorting my grip screws I just ordered a bunch of those little rubber bands that go on the screws and put them on all my 1911s.

Len

 cheap fix

http://www.ebay.com/itm/MIL-SPEC-12-Grip-Screws-O-rings-1911-Colt-Sig-Remington-Ruger-Kimber-Smith-CZ-FN-/222129570770?hash=item33b7f443d2:g:33QAAOSwhOBXUFOr

Never heard of these. I'm always learning. Thanks.

Vern

I'd suggest removing your grip safety and perhaps your grips then try releasing the slide again with Dummy rounds( no primer or a used primer case).  this will allow you to observe the trigger bow, disconnector , sear & hammer.  when you hold the trigger back you are also holding pressure on those areas. when you don't,  the impact of the slide can jar the internals.

grips screws are all over the place on length. That and the screw holes on grips vary. if the screw pushes on the mag then it can bind the release as well as potentially the trigger bow. over tightening the grip screw could well warp the frame just enough to bind the release too.. heck I've seen a Remington 700 receiver warp when it was pulled down on a badly bedded stock.. Never would have believed it until I watched the Mics

just some thoughts

BE Mike wrote:

OldMaster66 wrote:Instead of shorting my grip screws I just ordered a bunch of those little rubber bands that go on the screws and put them on all my 1911s

http://www.ebay.com/itm/MIL-SPEC-12-Grip-Screws-O-rings-1911-Colt-Sig-Remington-Ruger-Kimber-Smith-CZ-FN-/222129570770?hash=item33b7f443d2:g:33QAAOSwhOBXUFOr

There's also Challis,  lots of nice stuff.

http://www.challisgrips.com/c/18-Bushings-Accessories.aspx

http://www.challisgrips.com/pg/17-Hex-Drive-Bushings.aspx

their bushing extractor is the cat's ***

it work on pretty much any bushing staked or not

I tried loosening the grip screws. No difference. After watching, feeling, and listening, I finally decided to put the original Kimber hammer and strut back in and remove the Cylinder and Slide and Ed Brown strut. For what ever reason it corrected the problem. I tried different sears and different leaf springs and no change. The only thing that affected it was the Cylinder and Slide hammer and Ed Brown strut. I think I am going to get a different strut and see if that makes a difference. Thanks for all your suggestions.

try the EGW strut.

Vern,  There are actually two things different when you drop the slide with the trigger pulled and without. I have been gnawing on this bone trying to figure out why the difference. The other difference (possibly) is the grip safety firing pin disconnect. If you are not holding the pistol like you were ready to fire you may be only partially disconnecting that safety. The other components might be just wide enough to be affected by that difference. That grip safety firing pin disconnect is only found in Kimber II series. Just a thought but you would have to put your other parts back in to test this theory. If you were not holding the pistol like you were ready to fire it when you dropped the slide it might be worth testing.

Len

The grip safety has a leg that sticks forward and blocks the trigger. It blocks the trigger when it's not depressed. If it was not properly fit it could be dragging on the rear of the trigger causing the additional pull weight.
Jon

I'm assuming that this happen with an empty magazine installed. I can see the screws pushing the magazine onto the trigger bow and may be a cause of the changes in pull weight by letting the trigger reset without finger pressure. Rather that it being a deflection of the frame it's simply the trigger rubbing on the magazine that is increased by the slightly longer screw.
 What I'm thinking is that there is some type of friction causing the trigger to "gain " weight when allowed to travel forward without finger pressure. The faster forward might overcome this obstruction where as when released by the finger the forward travels at a slower speed stops when it reaches this obstruction. It can be caused by many things. The finger section of the trigger hitting the frame above or the trigger guard below. Possibly the bow going farther forward into a tight area that it doesn't when released by the finger. Maybe the disconnector "wedging" into the slot on the slide being slightly smaller, misaligned or slight burr. Try checking the pull weight to see if the change occurs with out the slide on the gun. To eliminate any grip safety issues, remove it and test to see if there is a weight change as described. Possibly remove the hammer and everything else except the trigger and mag. release, push the trigger forward with at least some force to overcome any obstruction then hold the frame vertically and see if the trigger slides without restriction, if not insert the magazine and try again.

Jon Eulette wrote:The grip safety has a leg that sticks forward and blocks the trigger. It blocks the trigger when it's not depressed. If it was not properly fit it could be dragging on the rear of the trigger causing the additional pull weight.
Jon

This happened on my Kimber.  It was ok with all the stock parts, but once I started changing hammer, sear, trigger, etc I had a problem. There wasn't enough clearance to let the trigger come back far enough to fully release the sear.