1911 Barrel Bushing

[schmeky]

Trying to improve the accuracy of my early model Kimber Classic Custom. I measured the front and here's what I got:

Barrel O.D. .580

Bushing I.D. .583

Bushing O.D. .700

Slide I.D. .702

I had a SS bushing in my parts bin and it measures:

Bushing I.D. .582

Bushing O.D. .701


The SS bushing needs a light tapping to install and a bushing wrench to turn. This bushing closes the barrel O.D. / Bushing I.D. clearance by .001. My question is, will this SS bushing show any practical improvement in accuracy as opposed to the original bushing?

 

[MT GUNNY]

I would Try it ! Make shure you lube the barrel and the ID of the Bushing.

Lube the bushing Prior to Install for easier removal.

 

[krs]

My question is, will this SS bushing show any practical improvement in accuracy as opposed to the original bushing?

Yes.

 

[JDGray]

Heres what removing .011 total clearance from my Springfield Loaded did for my groups. I ended up with .001 barrel to bushing, bushing just installed in frame by hand, no seen movement. Believe it or not, the first group was the best group the pistol had shot, before replacing the bushing, and that includes off of a rest. The wild shot in the bull, ruining my group, was my fault

 

[wv109323]

I understand that .004" equals about 2 1/2" at fifty. So .001 would be 25% of 2 1/2" at 50 Yards.

 

[krs]

I understand that .004" equals about 2 1/2" at fifty. So .001 would be 25% of 2 1/2" at 50 Yards.

It's not a formula and there's no set corelation between bushing clearance and group sizes. If you form expectations around the sorts of computations you've expressed here your expectations will not be met.

 

[schmeky]

I made a bushing mandrel to mount in my mini mill, bought a size "B" reamer, then slowly worked an oversized Ed Brown barrel bushing to fit the slide/barrel. The slide/bushing fit is very tight; the bushing can be removed with a wrench and feels identical to my Les Baer. The bushing I.D. to barrel O.D. is .001", .

This new bushing has altered the feel of the action. It now feels a lot like my Les Baer on lock-up. I shot this Kimber, using a 25 yard rest, before the bushing change. I could pretty easily do 2.00-1.50" groups.

I plan on trying it again a 25 yards to see if there is any improvement. My eyesight and target acuity may be more of a factor than the mechanical accuracy of this particular pistol.

It's going to interesting (for me).

 

[bofe954]

EGW will make bushings to whatever sizes you specify for a pretty reasonable price.

 

[JackOfAllTradesMasterAtNone]

Oh.. somebody posted it before... Kunhousen's list of five that most affected the accuracy of a 1911.

Bushing/barrel/slide fit was on that list. But the combination of the items on the list that allowed the gun to lockup and fire, repeating the same mechanical routine as identical as the last and subseqent shot is what truly makes a 1911 consitantly accurate.

Regarding your bushing, I've done the same with my Kimber Stainless II that I shoot Bullseye with. Reduced group sizes at 50yds by more than 1 1/2 inches. -as fired from Ransom rest.

-Steve

 

[schmeky]

Wow,

Thanx Steve. I realize the barrel bushing alone is contributor to good accuracy, the sum total of other areas is critical as well. I say this since I am about to try my first match barrel installation. I have read everything I can get my hands on, have both of "Jerry's" books and have studied them judiciously. I also have 2 reference pistols, my Kimber and my Les Baer (LB). I am trying to acheive a barrel install that will mimic the LB, which is fitted to an extrodinary degree of precision.

My particular Kimber, a very early model Classic Custom, has a near match grade fitted barrel in the barrel hood, upper lug, and lower barrel lug areas.

I feel this new bushing will optimize and enhance the overall fit of this Kimbers barrel. At least I hope it will

 

[schmeky]

Here's the results of my home barrel bushing install. Before, the best groups I could manage were around 1.5". The picture shows 5 rounds in 3/4", with 2 rounds opening up the group to 1.25".

I'm happy. Were the results worth the effort? For me it was since I covet accuracy. Did this make a big difference? No, not really. There's not a lot of practical difference between 1.5" and 1.25". However, I have never been able to do a singe hole at 25 yards in the past with this pistol. So 5 rounds in 3/4" is a marked improvement for this old, well worn, shot a lot Kimber.