Barrel/Chamber Support

[The_Shadow]

Now the $64 question?  Is the Kimber barrel considered a Nowlin ramp cut? or Clark Ramp Cut?   
BTW I'm impressed with the Kimber's chamber support!  I wonder how it compares to the Fusion design? 

[sqlbullet]

That is a Nowlin/Wilson cut.  Clark/Para is rounded on the rear of the lug where the barrel hits the frame.

[The_Shadow]

Thanks sqlbullet, when it comes to 1911's I'm not totally up to speed  ...still learning though! 

[Deadguy]

Now the $64 question?  Is the Kimber barrel considered a Nowlin ramp cut? or Clark Ramp Cut?   
BTW I'm impressed with the Kimber's chamber support!  I wonder how it compares to the Fusion design? 

Shadow I'll try to remember to post a pic of the support in my CCO when I get to a desktop. I can say this, though.  The ramped STII I had was completely supported while the unramped barrel in my Fusion CCO is not. However, based on the pics of the DE, I'd say my CCO has better support than the DE.

By the way, I believe most of Fusion's barrels are Storm Lake.

[sqlbullet]

It really is about how the barrel is throated.  The pic I posted above if from the original barrel from my P12-45.  It was out and convenient to take a picture of as such.

The barrel in my P16-40 is the same Clark/Para ramp but it support isn't great.  Previous owner had the barrel throat enlarged during the guns life as an IPSC gun.  As a result it get the occasional smile on brass when the "perfect" convergence of factors occurs.

A standard 1911 barrel, non-ramped can be cut to provide really good support, but you have to start with a completely un-throated barrel and cut the throat as a part of the fit to the gun.  That is probably what Fusion does.

Having the frame cut is only about $50.  Fitting a new barrel is the spendy part.  You are probaby still looking at $500 by the time you buy the barrel ($200), have the frame cut ($50) and pay to have the barrel fit to the gun ($200).  Not a cheap game.

[Yondering]

It really is about how the barrel is throated. 

sqlbullet, something's getting lost in translation in that last post. The throat is the transition area between the chamber and rifling; it's at the front of the chamber and has nothing to do with case support or barrel fit. The throat is the same thing whether we're talking about a pistol, revolver, rifle, or shotgun, although in a shotgun it's usually called the "forcing cone".

I think you mean the feed ramp? Even unramped 1911 barrels still have a feed ramp, although it is small.

[Vice]

Yondering, you bring up an excellent point.

I have always thought though, when it came to 1911s, and other semi-autos,  throating referred to "slicking" up the feed ramp for reliability.

Althought what you say is true.

[Yondering]

When used correctly, the term "throating", as in a long-throated competition gun, involves lengthening the throat so the rounds can be loaded long. A good example of this is the long-throated P16-40 I had, where the 40 S&W rounds could be loaded long, to the same length and velocity specs as 10mm.

Of course, the term does get used incorrectly, like the post above, which does add to the confusion about what it really means.

[sqlbullet]

I ain't going to say who is wrong and who is right, or even if there is one.

But, when referring to the back of a 1911 chamber where the feed ramps are I have always heard it referred to as the throat.  American Rifleman seems to use the term like I do in the context of a 1911 barrel.

http://www.americanrifleman.org/GalleryItem.aspx?cid=22&gid=118&id=1027

Asking google about a 1911 throat seems to predominately bring up information about modifying 1911 barrels at the breech.  And calling this area a ramp can be confusing too since when you order a 1911 barrel you order no-ramp/un-ramped, Clark/Para ramp, or Wilson/Nowlin ramp.

I agree the term is used to refer to the front of the chamber immediately before the leade.

In computer programming we call this function/method overloading, when you use one term for multiple items and the meaning has to be inferred by context.  Less than ideal all the way around.

[Vice]

Function method overloading-  what a mouthful 

I just learned something and it makes sense.  I wish they had less complex verbage.  Leave it to the computer geeks to make it harder than what it is.

[Deadguy]

side by side of conventional barrel (Fusion CCO) and ramped barrel (Kimber STII)







and here is a barrel that has not been throated.  From a 1975 Colt LWT Commander

[EdMc]

The Fusion barrel looks quite like a Colt Delta barrel. The Commander barrel has what I call a feed ramp machined @ 6 o'clock. Thanks for posting the photos.

[Deadguy]

The Fusion barrel looks quite like a Colt Delta barrel. The Commander barrel has what I call a feed ramp machined @ 6 o'clock. Thanks for posting the photos.

Indeed.  After looking at the DE and the CCO barrels together, they are all but identical in support.  I have had no problems with the Underwood DE loads WRT case bulges, etc. 

[REDLINE]

Wow, I was under the impression that the Fusion barrel would have more support.  Just looking at the pick it looks worse than Glock 10mm barrels, and more/less like Colt DE barrels as has been mentioned.

[Deadguy]

Wow, I was under the impression that the Fusion barrel would have more support.  Just looking at the pick it looks worse than Glock 10mm barrels, and more/less like Colt DE barrels as has been mentioned.

I also would like to know if any of the 5" conventional barrels used in Fusion builds have similar support.  Could be that the commander length 10mm barrels are done this way for more reliable feeding.