ultra cdp II barrel

[angedky(mr)]

this one just jumped out at me !! ............. pistol is a Ultra CDP II has about 3500 rounds thru it, until recently hadnt seen much useage around early Oct. I started putting 250 WWB / week. Tore her down the other day for complete inspection (having just read a ton of literature here and considering a new 1st build) looky what I found

http://i24.photobucket.com/albums/c23/angedky/0002.jpg

http://i24.photobucket.com/albums/c23/angedky/0003.jpg

http://i24.photobucket.com/albums/c23/angedky/0001.jpg

Obviously the ol' girl has a couple issues !! BTW Slide / Barrel clearance in full linkdown is non existant My question is is this barrel worth saving or should I just get another and fit it up properly ?? If a new one is in order any MFG preferences?? I could sent it back to Kimber, but wont they just fit it quick and dirty (1 lug load bearing surface) so I really got no where in a hurry ?? or am I really overthinking this one (i do tend to be a little butt-retentive about things at times) My primary concern if old barrel is kept is structural integrity of lugs after taking such a beating .............

[1911Tuner]

Howdy and top o' the mornin' to ya.

Hard to tell from your photos...

The lack of visible clearance isn't really a major issue as long as the lugs aren't rolled or peened on the front corners...other than scuffing the hood.
If the lugs look okay, you have some clearance...you just can't see it.
I prefer to see at least .012 inch and am happier with .015 or even more. if the timing is okay, with the lack of clearance, you'll just have to be meticulous about keeping the gun clean since dirt or gunk buildup could cause the barrel lugs to be rolled by the slide as it passes overhead. You can check for a little clearance with a strip if typing paper. If it's tight, there's not enough clearance.
Slip-fit with two strips of paper indicates just enough. Don't push down on the hood to get more clearance.

Note that light flanging on the tops of the lugs is probably due to seating, and doesn't hurt anything unless the lug is set back far enough to increase headspace past the maximum allowable, and the corners still look good.

Lug corners that are lightly beveled sometimes means that somebody put them there on purpose, either to provide a little more time for the barrel to clear the slide, or to help engage the lugs as the barrel engages the slide
with a tight hood to breechface fit. This should be very even and clean.
Any indication that the bevel appeared as a result of incorrect linkdown/drop timing isn't good. In that case, it will be ragged and uneven.

Which lug is bearing the load? If it's #1 and you have adequate vertical engagement...90% or more...it'll do pretty well. Many top smiths now only fit to the #1 lug with very good results.

[angedky(mr)]

I will try to get some better pics shortly and my next step is timing test as specified by the scheumann barrel site (with out removing any material) the Kuhnhausen manuals are on the way I will say that the edge of the "chamber lug" appears to have the edge battered by the heavy useage, this pistol was purchased new by myself and has never seen any mods (other than new mags due to kimber followers rocking foward) also clearance between hood and breach face appears to be .0215 (breach face to front slide lug 1.3165 minus hood to face of chamber lug 1.2950 ) lastly the middle and muzzle lug on the barrel are starting to show signs of polish (front half of top surface on both lugs) this is what caught my attention. will fix the picture issues and post better ones here

regards

angedky(mr)

p.s. what are the specific numbers for the corresponding lugs as i am refering to them by location (incorrectly so !!)

[angedky(mr)]

Problem solved.............. many thanks tuner for taking the time to reply. I had checked this pistol top to bottom right to left over and over and over watching each part move thru its cycle again and again, until it dawned on me I hadnt changed the recoil spring since I bought it new !!! so I called the folks at the custom shop and asked what signs could show from a severly worn spring (about 2700 rounds )past due, interestingly enought they told me exactly what i had in my hands.................. new part on the way soon to be up and running...........final question stay with 18lb oem or up it to a 21lb wolff ?? im thinking 21lb but have no real world experience to base this on............... again tuner thanks for the time, sorry i wasted it !!

[1911Tuner]

I will try to get some better pics shortly and my next step is timing test as specified by the scheumann barrel site (with out removing any material) the Kuhnhausen manuals are on the way I will say that the edge of the "chamber lug" appears to have the edge battered by the heavy useage, this pistol was purchased new by myself and has never seen any mods (other than new mags due to kimber followers rocking foward) also clearance between hood and breach face appears to be .0215 (breach face to front slide lug 1.3165 minus hood to face of chamber lug 1.2950 ) lastly the middle and muzzle lug on the barrel are starting to show signs of polish (front half of top surface on both lugs) this is what caught my attention. will fix the picture issues and post better ones here

regards

angedky(mr)

p.s. what are the specific numbers for the corresponding lugs as i am refering to them by location (incorrectly so !!)

First lug wall in front of the chamber...the one without a slot behind it...is #1.
Count forward from there.

Tryin' to wrap my head around Springfield's comments as to how a worn recoil spring would cause an insufficient clearance issue. The clearance is a fixed mechanical/dimensional function, and if it's there, it's there...regardless of the recoil spring tension or lack thereof. Unlock/linkdown/drop timing is also fixed, and will occur at the same place regardless.

Also gotta ask how you arrived at the measurement between breechface and first lug abutment in the slide. .021 inch between hood and breechface is a lot, and the distance is best determined with a feeler gauge or shim stock slipped into the breech between slide and hood as the barrel locks in. Determining the exact distances between breechface and the slide's lug abutments require an adjustable gauge block that can be fit between the two points with light interference...locked down...removed...and measured.

[angedky(mr)]

mfg's comment ....................... I assumed they were on track because I made him tell me what damage I could most likely see (with worn spring) before I told him what damage was actually on pistol and he described what I saw in my hands flanged #1 lug, top foward 1/2 of #2 & #3 starting to polish. Based on that I took his word for it


My measurments..........derived from measuring barrel hood face to #1 lug face with starrett digital calipers (1.2950 ) and on the slide using a telescoping gauge between breech face and the rear face of #1 slide lug (same location as foward wall of ejection port although eject port wall is slightly smaller ) telescope gauges transferred to dig calipers revealed 1.3165 subtract the two is how I came to .0215 HOWEVER this morning with pistol fully assembled, just going into battery .010 brass shim stock locks it up.same to say my measurements were full of "sheepdip" !!!

measurement #2............. with slide .250 before battery, held muzzle up hood slide clearance is about .0095 (.010 brass is tight fit .009 brass is sloppy) good to go there as well



muchas gracias

angedky(mr)

[1911Tuner]

As long as the barrel to slide clearance is there without pushing down on the barrel, .0095 is probably okay. If you have to push to get it, light clearancing of the front radius of the lower lug and maybe a little in the top of the link hole to speed up the barrel drop may be a good idea. .0095 is a little tight for my comfort, but likely okay if the barrel drops on its own.
The flanging is probably due to pressure seating/equalizing, and as long as the front corners are square and sharp, you probably don't have anything to worry about. Keep an eye on it, though. Any sign of damage at the corners
indicates a barrel timing issue, and if caught in time can probably be corrected.

[angedky(mr)]

lugs appear to be square under a large magnifying glass, the link hole for the slide stop pin is outta round .0036 ( with link at 90 to barrel measured vertical and horizontal diameter 5X average is .2133 vert and .2097 horiz) seems to me a little link stretch is happening. gonna put 500 thru her 100 / time and measure in between........we'll see what happens, Thankyou so much for all your help

[warmrain]

Johnny,

I'm having difficulting seeing the issue in the photos unless it is the very hard to detect rounding over of the lug edge in the first photo...

But this thread causes me to think of one of my own Kimber Ultra CDP's barrel looks like. This particular example has between 800 and 1000 rounds. It broke in around 600 or so and had been perfect since.

I'm looking at the lug closest to the muzzle, specifically the top edge of the kug closest to the muzzle. I beleive these scallops have been there from the beginning...? The slide is absolutely unremarkable. Under the brightest light and using a magnifying glass the surfaces in the slide are clean and square.

Is this something I should be concerned with?

Thanks!

(The barrel you are looking at has recently been treated with a Robar NP3 coating.)

http://i27.photobucket.com/albums/c151/warmrain/UltraCDP2004bbl.jpg

[angedky(mr)]

warmrain, tuner

This is a better photo of whats going on with the #1 lug
http://i24.photobucket.com/albums/c23/angedky/IMG_0002.jpg
http://i24.photobucket.com/albums/c23/angedky/IMG_0005.jpg
also look at the front radius on lower lug (left side) appears to have been beaten into a angle rather than radius
left side :
http://i24.photobucket.com/albums/c23/angedky/IMG_0007.jpg
and the right side appears more or less undamaged in comparison
right:
http://i24.photobucket.com/albums/c23/angedky/IMG_0008.jpg

[warmrain]

angedky,
Yes, the top two (new) photos make it obvious and is what I thought I saw. Forgive my being obtuse, but I don't understand the last 2 new photos...

[angedky(mr)]

on the front radius of the lower lug it is my understanding that the slide stop pin actually follows this curve up and down as the barrel locks or unlocks and it appears in this pistol that the radius and the pin are impacting rather than one riding around the other creating the flat spots.....what you are looking at next to the lugs in each picture is a starrett radius gauge that shows a perfect precision ground radius (this condition pictured here may or may not be normal) I posted it in hopes that the pics along with the link pin hole diameters may provide some insight as to what is happening inside............. in hopes it will concrete tuners suspicions for him, if not its just more info for us all to hash over --have a good evening

angedky(mr)

[warmrain]

angedky(mr),
It just occurred to me that my posting of my barrel in your post might be something I once heard described as "hijacking a thread". I appologize if I have acted improperly. Your post caused be to investigate something very similar on the exact same make and model and I though the post was relevant...

[angedky(mr)]

no apology needed.............as you are right (as I see it) in your initial assumptions "same issue, same model might as well post" Im not one for proper internet protocol myself. In fact, I had a cable modem live chat technician tell me to take off my caps and "quit shouting" at him.........geez where do they find 'em these days

UPDATE on pistol, cleaned up the barrel lugs nice and neat, replaced springs so far 350 thru her and no dimensional changes. Pressure seated lugs Tuner is dead on the money..............carrying on smartly here

Angedky(mr)

[warmrain]

angedky(mr),

THANKS! :p
I wonder what's going on with mine? :confused:
Or if it;s anything at all to consern myself with... :(
I should mention it runs perfectly and has since around 500 somewhere (< 1000 now).