45ACP/super Compensator .....

Ian

Notorious member
I don't know your technical level on 1911 barrel fitting, if you don't have a book on the subject or some in-depth schooling from someone who fully understands the nuances of the process, it may be helpful to go back to the drawing board and do some basic fitment checks. I can point you to some good articles and videos on-line if you like. The compensator mass should delay unlocking somewhat (and cause failure to fully cycle if too heavy), so that's working in your favor. Limp-wristing is a no-no, especially with the comp, so a lighter spring may not solve your cycling problems completely. Another thing to examine closely is the barrel ramp-to-frame ramp interface, if there's any overhang to the rear or even a dead match, the bullet nose can bite the bottom edge of the barrel ramp and cause a stoppage or suck enough inertia out of the slide to prevent it going fully into battery. The barrel ramp needs to be at least .005" ahead of the frame ramp as the bullet feeds, check by pulling the slide about halfway back and pull all the slack out of the barrel to the front by grabbing the compensator and pulling forward. Examine the feed ramps and you should see a tiny bit of flat frame between the two, i.e. the barrel ramp in front of the frame ramp ever so slightly.
 

Hawk

North Central Texas
That flame bloom is on full daylight.
Imagine firing that puppy in the dark, at night!
It is pretty much like my 10MM and why I am trying to find a good flash suppressed powder with a burn rate similar to Blue Dot.
What powder was that?
 

wquiles

Well-Known Member
I don't know your technical level on 1911 barrel fitting, if you don't have a book on the subject or some in-depth schooling from someone who fully understands the nuances of the process, it may be helpful to go back to the drawing board and do some basic fitment checks. I can point you to some good articles and videos on-line if you like. The compensator mass should delay unlocking somewhat (and cause failure to fully cycle if too heavy), so that's working in your favor. Limp-wristing is a no-no, especially with the comp, so a lighter spring may not solve your cycling problems completely. Another thing to examine closely is the barrel ramp-to-frame ramp interface, if there's any overhang to the rear or even a dead match, the bullet nose can bite the bottom edge of the barrel ramp and cause a stoppage or suck enough inertia out of the slide to prevent it going fully into battery. The barrel ramp needs to be at least .005" ahead of the frame ramp as the bullet feeds, check by pulling the slide about halfway back and pull all the slack out of the barrel to the front by grabbing the compensator and pulling forward. Examine the feed ramps and you should see a tiny bit of flat frame between the two, i.e. the barrel ramp in front of the frame ramp ever so slightly.
Little to none experience, as this was my first attempt :)

I do have a gap as you point above, that was one I was aware off.

Yes, please send me the links/videos. I did review several sources, but I have never been totally confident that I got everything "right" and I do want to learn how to do it right.
 

wquiles

Well-Known Member
That flame bloom is on full daylight.
Imagine firing that puppy in the dark, at night!
It is pretty much like my 10MM and why I am trying to find a good flash suppressed powder with a burn rate similar to Blue Dot.
What powder was that?
That powder was "Power Pistol". It and 800x give the most velocity with least pressure for the 45 Super, which is why many use these two powders. But yes, that is quite the flame :)
 
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Ian

Notorious member
First check after triple-checking for unloaded is slide home, hammer back, thumb safety off, then press down on the chamber area of the barrel with your thumb. Try to push the barrel straight down toward the trigger opening in the frame. Putting the frame in a vise may help you see exactly how much movement there is, and there should be very little. There also should be very little slide to frame movement if you squeeze the slide down hard against the frame. While checking for slack, peer into the muzzle with a pen light and observe if the firing pin is centered in relationship to the chamber. These checks will determine if your slide to frame and barrel to slide and barrel to slide stop relationships are correct. You should also check to make sure the barrel bushing has the correct relief to allow the barrel lugs to fully engage the slide lugs, check that with the slide off the frame and the barrel installed, measure the distance between top of slide and barrel hood with a depth mic while fully engaged and compare to how it measures with the pistol together and in battery. When the slide is off and upside-down, the barrel should "clink" all the way into battery and not be held up by the barrel bushing. If the lugs don't fall all the way into engagement with gravity and you can push the barrel further into lockup against the spring of bushing flex, the bushing needs to be relieved very slightly. If there is an uneven wear pattern on the barrel from the bushing it's also an indicator of a binding condition. While you have the slide off, upside down, and barrel nesting in battery, twist the barrel back and forth to check for excess side-play within the slide, there should be almost none in a match pistol and will probably be a huge amount with a "drop-in" or production barrel. Look in the muzzle again to see if the firing pin hole lines up laterally with the chamber.

Headspace is another thing to check with the slide off, I'm sure you went through this process if fitting a "drop-in" barrel because the only surface with enough meat to file on will be the very back of the barrel hood where it rides the breech face. Basically there should be an absolute minimum of slack between the breech face and barrel hood when the barrel is locked up, essentially the barrel should be snug against the slide when in battery with no fore-aft movement at all.

An important and often overlooked consideration when checking all the things that interface in a 1911 is the function of the barrel link, which is only one thing: It forces the barrel to "rotate" down and out of battery as the slide comes back, that's it. The feature of rotating BACK into battery is controlled by the ramp on the barrel feet and slide stop pin and there should be no stress on the link at all except when unlocking.
 

wquiles

Well-Known Member
Wow, thanks again Ian. It will be Thu/Fri before I can check and take pictures, but I will and report back :)
 

Pistolero

Well-Known Member
And understand that the bottom surface of the barrel lugs are what drives the barrel up, not
the link. The link is there to pull the barrel down. Even lug bearing on the slide stop pin is important
to function and accuracy.

Bill
 

wquiles

Well-Known Member
OK, let the learning process begin. I took pictures, and videos, and took a measurement -)

Barrel lug engagement = 0.042"

Photos of the bottom of the barrel:
IMAG0005.jpg


IMAG0001.jpg


IMAG0002.jpg


IMAG0003.jpg


IMAG0004.jpg



Photo of the gap between the frame and the edge of the barrel, barrel closest to the hammer/handle of gun (no spring) - note that in this photo the barrel appears to be touching the frame slightly:
IMAG0008.jpg


And the same setup, but pulling the barrel towards bullet travel (again, no spring) - note there is a gap between barrel & frame where it appears barrel is above the frame, not touching the frame:
IMAG0007.jpg




And finally some videos :)
barrel lock/unlock without recoil spring

barrel with recoil spring

barrel with recoil spring - closeup of locking area


OK - feedback, suggestions?

Will
 
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Ian

Notorious member
When the frame is held in the vise as in the videos, hoew much up/down movement does the slide have against the frame, and when locked up, can you press down just on the barrel through the ejection port and get it to move at all?

The ramp looks about right to me, but in the videos has a tiny bit of ramp bumping it up a little more at the very end of travel. However, that's a lot better than many barrels that have a steep angle on the feet all the way to the stop radius.
 

Ian

Notorious member
The link hole should line up with the stop radius so the stop pin doesn't bind the link pin.

20190428_115642.jpg
 

Ian

Notorious member
The back side of the barrel feet should contact the vertical recoil surface of the frame about the same time as the bottom of the chamber contacts the horizontal recoil surface. The barrel should settle into the frame so that the link is not stressed. If the barrel isn't resting on the horizontal surface when all the way back (where the feed ramps meet) then something is wrong.

20190428_120520.jpg
 

Brad

Benevolent Overlord and site owner
Staff member
If your 1911 is that clean them something is wrong.
 

Ian

Notorious member
See the little "bowtie" shaped shiny spot on the back side of the barrel feet? That's vertical recoil surface contact, how it's supposed to look. Note the frame isn't contacting the barrel at the very corner of the feet/barrel junction, you don't want that because it would make a stress raiser.

20190428_121334.jpg
 

Ian

Notorious member
In the center of this photo note the light reflecting off of the horizontal recoil surface where the barrel has been hitting it nice and square. Also note that the bowtie on the frame has undisturbed filth on it because it has NOT been contacting the barrel.

20190428_122057.jpg
 

Brad

Benevolent Overlord and site owner
Staff member
Ian, is this a handgun you fit or did it come from the manufacturer that way?
If you fit things, what did you do?
 

Ian

Notorious member
I fit a semi-drop-in barrel. Surprisingly it made a "production" fit pretty well with just filing the hood. I did have to work on the barrel lugs with a stone to get rid of some of the coating and get even engagement on the recoil side of all three lugs. The link and feet fit the frame dimensions perfectly, but the chamber overhung the frame ramp (Dremel to the barrel ramp fixed it) and I had to have a friend relieve the barrel in front of the chamber on his lathe because it was made to the 5" form and not Commander form and nearly blew the bushing through the end of the slide first time I fired it.

I still need to buy a bar set and peen the frame rail corners to take about .020" of vertical slop out of the slide. The barrel and link fit the frame perfectly, but the slide rides too high and it doesn't get as much lug engagement as it should.

20190428_123132.jpg
 

Ian

Notorious member
Yeah, your slide fit is almost as bad as mine.

Being able to poke the barrel down like that after lockup is less than ideal. Tightening the slide downward is the only thing you can do to fix it other than replace the barrel with a custom-fit one that requires cutting the barrel feet after fitting the slide to frame and recoil lug/slide engagement and headspace. With as much engagement as you have I don't see it being a safety issue, but definitely an accuracy issue, particularly with certical inconsistencies.

Another thing you could do to help smooth tje function is to remove the barrel link and pin and polish the convex radius on the front of the barrel feet, being very careful to keep them square. File marks and burrs on the ramps of the feet will cause drag on the slide stop pin, you want that as smooth as possible for function. There's a lot going on in the last 1/4" of slide movement into battery with the feet riding the stop pin, the lugs going into battery, extractor climbing up the case rim, barrel hood riding the breech face, barrel tilting in the bushing, and the disconnector riding its indent. If any of these points bind, are rough, or out of time, the function will be poor.
 

Pistolero

Well-Known Member
If the bbl can move down when in lockup, like Ian said, the barrel lugs are too short. Peening down the
rails is the only fix with existing parts, and may not be enough there to get rid of all of it.

OTOH, how accurate is it now and how does that relate to your requirements?

This is where you really start to appreciate one of my Wilson guns, or a Dan Wesson. All the pieces
are RIGHT when you get it. Zero play in the DW slide-to-frame, but runs like on ball bearings.
Not cheap, but at least you are getting what you pay for.

Bill
 
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