Flared pistol barrel

imp · June 23, 2019, 10:19 PM

I've noticed some pistols have barrels that have a constriction and then a flare on the outside near the muzzle. The popular models that come to mind are 3rd gen Smith and Wesson 9mms, and keltec autos, and I know there are more. What is the purpose of this shape? http://http://media.midwayusa.com/productimages/880x660/Primary/494/494979.jpg

Bill DeShivs · June 23, 2019, 10:31 PM

The shape allows a tight fit in the barrel bushing for accuracy, and allows for clearance when the slide retracts.

Old 454 · June 24, 2019, 05:23 AM

I believe there called Bull barrels

jar · June 24, 2019, 06:55 AM

One of the more extreme modern examples I'm aware of is on the Sig P290RS. In the first picture you see the 380 version in blue and the 9mm Para in red.

And then with the slide locked back to show the barrel flare.

Jim Watson · June 24, 2019, 09:02 AM

The muzzle of the S&W and Keltec are shaped to allow the barrel to tip up and down to lock and unlock.

The Sig shown has a flared muzzle to fill the slide bore. Lots of shortened 1911 types do because the barrel comes out to the front and the locking lugs end up too close to the front of the slide for a bushing.

Sluggederbore · June 30, 2019, 09:19 PM

I thought the flare was to use them like a blunderbuss with shotshells.

**44 AMP** · June 30, 2019, 10:49 PM

Quote:

I thought the flare was to use them like a blunderbuss with shotshells.

I will assume this is sarcasm.

The flare of a blunderbuss was widely thought to spread the shot, but it really doesn't. What is does do is provide a nicely large "funnel" on the end of the barrel to make loading in a hurry or on the move easier.

tipoc · July 1, 2019, 12:27 PM

The OP here kindly offered us a pic of what he was asking about which is similar to this one on the 3rd Gen S&W semis...

Bill De Shivs answered that one correctly:

Quote:

The shape allows a tight fit in the barrel bushing for accuracy, and allows for clearance when the slide retracts.

It's not a Bull Barrel that's different but has similar results. We see this type most often (maybe always) with fixed bushings as distinct from removable bushings like the 1911.

tipoc

SIGSHR · July 1, 2019, 02:13 PM

IIRC that design allows a better fit without a separate bushing.
A bul barrel is a heavy barrel of the same diameter from muzzle to frame-the heavy barrel S&W Model 10 or M-58, e.g.

tipoc · July 1, 2019, 04:18 PM

A bull barrel in a revolver is a different creature altogether from a bull barrel in a semi.

In a semi it's a barrel that has a diameter at the muzzle end that mates to the slide and not to a bushing. It does away with the bushing altogether. It is substantially thicker and heavier at the muzzle end than towards the chamber.

You can see that clearly in this early Detonics Combat Master. This was one of the first guns to use a bull barrel. In this case the barrel behind the muzzle was cut and shaped to a smaller diameter. I usually see this in compact and sub-compact guns.

Below is a vid that explains it some. It's too long so skip to the 1 minute mark.

https://www.youtube.com/watch?v=XtXrol3gmYQ

tipoc

T. O'Heir · July 2, 2019, 12:39 PM

A blunderbuss didn't use shot shells. Usually didn't use shot either. Bits of metal. Stones or gravel and whatever else was laying around.
"..."funnel" on the end of the barrel..." Yep. Made 'em scarier looking too.
"...It's not a Bull Barrel..." Exactly. It's about clearance upon cycling and the fit to the bushing when in battery. We used to machine 5 thou off the body of 1911/1911A1 barrels leaving the last half inch alone for the same reason.

briandg · July 3, 2019, 03:43 PM

Just to add something, if you look at some of the available handguns you will find some slides are relieved where the barrel meets the slide. This allows the barrel to tip down unimpeded, just as the ball at the end of the mentioned barrel does.

My bodyguard is tapered this way and I believe that the glock is as well.

June 23, 2019, 10:19 PM	#1
imp Senior Member Join Date: November 11, 2006 Posts: 626	Flared pistol barrel I've noticed some pistols have barrels that have a constriction and then a flare on the outside near the muzzle. The popular models that come to mind are 3rd gen Smith and Wesson 9mms, and keltec autos, and I know there are more. What is the purpose of this shape? http://http://media.midwayusa.com/productimages/880x660/Primary/494/494979.jpg

June 23, 2019, 10:31 PM	#2
Bill DeShivs Senior Member Join Date: April 7, 2006 Posts: 10,985	The shape allows a tight fit in the barrel bushing for accuracy, and allows for clearance when the slide retracts. __________________ Bill DeShivs, Master Cutler www.billdeshivs.com

June 24, 2019, 06:55 AM	#4
jar Senior Member Join Date: March 8, 2001 Location: Deep South Texas Posts: 1,669	One of the more extreme modern examples I'm aware of is on the Sig P290RS. In the first picture you see the 380 version in blue and the 9mm Para in red. And then with the slide locked back to show the barrel flare. __________________ To be vintage it's gotta be older than me!

July 1, 2019, 04:18 PM	#10
tipoc Senior Member Join Date: December 11, 2004 Location: Redwood City, Ca. Posts: 4,114	A bull barrel in a revolver is a different creature altogether from a bull barrel in a semi. In a semi it's a barrel that has a diameter at the muzzle end that mates to the slide and not to a bushing. It does away with the bushing altogether. It is substantially thicker and heavier at the muzzle end than towards the chamber. You can see that clearly in this early Detonics Combat Master. This was one of the first guns to use a bull barrel. In this case the barrel behind the muzzle was cut and shaped to a smaller diameter. I usually see this in compact and sub-compact guns. Below is a vid that explains it some. It's too long so skip to the 1 minute mark. https://www.youtube.com/watch?v=XtXrol3gmYQ tipoc __________________ 1. All guns are always loaded. 2. Never let the muzzle cover anything you are not willing to destroy. 3. Keep your finger off the trigger till you are ready to shoot. 4. Identify your target and know what is beyond it.

July 2, 2019, 12:39 PM	#11
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	A blunderbuss didn't use shot shells. Usually didn't use shot either. Bits of metal. Stones or gravel and whatever else was laying around. "..."funnel" on the end of the barrel..." Yep. Made 'em scarier looking too. "...It's not a Bull Barrel..." Exactly. It's about clearance upon cycling and the fit to the bushing when in battery. We used to machine 5 thou off the body of 1911/1911A1 barrels leaving the last half inch alone for the same reason. __________________ Spelling and grammar count!

June 24, 2019, 05:23 AM	#3
Old 454 Senior Member Join Date: August 15, 2011 Location: Chesterton Ind. Posts: 822	I believe there called Bull barrels

June 24, 2019, 09:02 AM	#5
Jim Watson Senior Member Join Date: October 25, 2001 Location: Alabama Posts: 18,542	The muzzle of the S&W and Keltec are shaped to allow the barrel to tip up and down to lock and unlock. The Sig shown has a flared muzzle to fill the slide bore. Lots of shortened 1911 types do because the barrel comes out to the front and the locking lugs end up too close to the front of the slide for a bushing.

June 30, 2019, 09:19 PM	#6
Sluggederbore Junior Member Join Date: December 12, 2010 Posts: 9	I thought the flare was to use them like a blunderbuss with shotshells.

July 1, 2019, 02:13 PM	#9
SIGSHR Senior Member Join Date: September 13, 2005 Posts: 4,700	IIRC that design allows a better fit without a separate bushing. A bul barrel is a heavy barrel of the same diameter from muzzle to frame-the heavy barrel S&W Model 10 or M-58, e.g.

July 3, 2019, 03:43 PM	#12
briandg Senior Member Join Date: May 4, 2010 Posts: 5,468	Just to add something, if you look at some of the available handguns you will find some slides are relieved where the barrel meets the slide. This allows the barrel to tip down unimpeded, just as the ball at the end of the mentioned barrel does. My bodyguard is tapered this way and I believe that the glock is as well. __________________ None.