KIMBER offers more barrel chamber support in 10mm than any other manufactuer?

Intercooler · December 04 2012 05:50:15 PM MST

Maybe this should be retitled or made a sticky.

Here is the new Rock Island 1911 10mm on the right:

REDLINE · December 05 2012 12:40:06 AM MST

Thanks for posting the pic of the RIA here for comparison.

This would be a great thread to sticky in regard to chamber support pics. And more pics could be added as time goes by.

If it would be considered for a sticky the thread could be renamed; 10mm Platform Chamber Support Pics

475/480 · December 05 2012 05:28:40 AM MST

It will take a day or two but I will get pictures taken of my Caspian 6" and the STI Perfect 10.

Sean

EdMc · December 05 2012 05:42:55 AM MST

Well, I had a photo of Kimber and Colt barrels, but none of my photos are showing on my Photobucket account. Odd? I'll post it later if my photos come back from cyber ether.....Seems to be working now...

sqlbullet · December 05 2012 07:31:26 AM MST

Thinking about it, these pictures don't tell the whole story with regard to case head support. If the barrel hood and the head of the case don't line up, then the support will be less than these pictures indicate, as the case will move back against the breach face when fired.

Just a thought.

REDLINE · December 05 2012 11:43:00 AM MST

So you're refering to headspace?

REDLINE · December 05 2012 11:43:32 AM MST

Quote from: 475/480 on December 05 2012 05:28:40 AM MST
It will take a day or two but I will get pictures taken of my Caspian 6" and the STI Perfect 10.

Sean

Awesome. Looking forward to them.

sqlbullet · December 05 2012 12:54:41 PM MST

Quote from: REDLINE on December 05 2012 11:43:00 AM MST
So you're refering to headspace?

Sorta...

I just mean if the chamber is reamed deep, then the amount of the head that is unsupported could vary a few thousandths when it is in firing position from when it is dropped in. I can take a barrel that appears to have poor support and make it look better by reaming the chamber a little deeper. It won't be better, but it will look better.

I don't know a good way to account for this.

The_Shadow · December 05 2012 01:22:00 PM MST

The barrel's hood determines the lockup position in relationship to the breech face amd lugs as they sit in the slide. If the chamber is cut too deep then the free floating distance of the cartridge can change but only by the slop in the extractor hook, (this is why the 40's can be shot from the 10mm barrels) however the same amount of unsupport is the same!

Therefore by design the ammount of unsupport will remain the same unless the design of the barrel is changed to incorporate a steeper feed ramp and surround the chamber with more barrel metal.

But keep in mind the angle to which the cartridge is being feed, as it tips into the chamber this can cause feeding issues, concerning cartridge overall length and bullet nose shapes and designs.

EdMc · December 05 2012 01:32:55 PM MST

So what about a looser overall chamber allowing more uniform expansion instead of concentration in one small area? Given that it will cause a loss of efficiency/lower velocity. Seems only the Kimber doesn't leave at least a small area at the feed ramp unsupported. Obviously I know nothing of pressure vessel physics. ${$default_grin_smiley}$

sqlbullet · December 05 2012 03:08:19 PM MST

Still don't think you guys are getting what I am saying.

If the chamber is cut deep, then in the pictures we take support may look good. But, when the cartridge is being held against the breach face by the extractor it may not look so good, cause it would be seated as deeply.

You are correct Ed, a looser chamber will produce a lower peak pressure than a tight one. Same with the bore. Tight bore produces higher pressure than a loose bore.

Most pressure barrels that are used by the big boys to produce load data and velocity numbers for factory ammo have minimum spec chambers and tight bores. As a result, the velocity numbers don't hold up well in the "real world".

Deadguy · December 05 2012 04:19:21 PM MST

Sql I understand what you are saying. I think most, if not all, manufacturers/pistolsmiths cut and fit barrels to prevent this type of situation. It could be deadly, or just plain painful and ugly, for the shooter regardless of the caliber. Now if bubba got a hold of the barrel....

sqlbullet · December 06 2012 07:54:47 AM MST

I will have to measure and report back what I find. Pretty sure mine vary a good bit (eg a couple thousandths).

475/480 · December 06 2012 09:42:47 AM MST

I took 10 pictures and these are the best pics I could get with a Nikon Coolpix (useless camera).
L- STI 10 MM
R- Clark barrel from my Caspian 10MM LS

Yondering · December 06 2012 10:05:03 AM MST

Quote from: sqlbullet on December 05 2012 12:54:41 PM MST
Quote from: REDLINE on December 05 2012 11:43:00 AM MST
So you're refering to headspace?

Sorta...

I just mean if the chamber is reamed deep, then the amount of the head that is unsupported could vary a few thousandths when it is in firing position from when it is dropped in. I can take a barrel that appears to have poor support and make it look better by reaming the chamber a little deeper. It won't be better, but it will look better.

I don't know a good way to account for this.

Yes, what you're describing is headspace.

Looking at EdMc's picture above, the Kimber barrel looks like it has deeper headspace than the colt. The barrel hood looks like it's sticking up past the brass on the Kimber.