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Measuring Barrel Length

62K views 36 replies 23 participants last post by  Argee1950 
#1 ·
I tried searching the forum, Google, and YouTube, and no one seems to agree on how to measure the barrel length on a revolver, so I’m posting this question.

How do you measure barrel length on a revolver. I’ve seen three answers to this, so by looking at my photo below, which is the proper way to measure barrel length?

A. From the end of the barrel to the front of the cylinder.

B. From the end of the barrel to the face of the forcing cone.

C. From the end of the barrel to the frame.

 
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#2 ·
I think B is the correct answer.

Do I win??? :D
 
#5 ·
It's in the fine print! ;)
 
#8 ·
"B" is the correct answer. You're measuing the barrel So it's from the muzzle to the face of the forcing cone where the barrel ends. Measure to the face of the cylinder is meauring longer than the actual barrel length.
 
#9 ·
Pull out one of your Rugers with a known barrel length. The only way you will get the known length is to measure it to the face of the cylinder. Ruger measures their barrels to face of the cylinder.

I'm not saying the barrel isn't shorter. I'm saying if you buy a Ruger revolver with a factory specified 5.5" barrel it is measured from the face of the cylinder to the muzzle.
 
#11 ·
BATF established an official way to measure revolver barrel lengths, which has been the traditional method since revolvers were invented. The answer is "A" and applies to all SA and DA revolvers. FYI, pistols are measured differently .... from the muzzle to the breach face.
 
#12 ·
So, if "A" is the correct answer (which I'm not saying it isn't), then the specified length of the barrel is actually the entire length of the barrel + the space between the cylinder face and the breach.

This was probably figured out by the same bunch that seem to think that a magazine that only holds 10 or less rounds is somehow less dangerous that one that holds over 10. :confused:
 
#13 ·
Barrel Length? Revolver versus Semi-Auto

This is an interesting question... one that I posed to the shopkeepers at a couple of LGS. BUT, my main question was aimed at comparing the barrel lengths of semi-autos to revolvers.

For example (without getting too technical), take a semi-auto with a 3" barrel and a round that lets say is 1" long and is chambered. Does that mean that the stated 3" barrel on the semi-auto is actually only 2" in real terms?

Or when comparing barrel lengths, is the 2" snubbie approximately equal in "real" barrel length with the 3" semi-auto since its round is chambered in the cylinder versus the first third of the 3" semi-auto barrel?
 
#15 ·
For example (without getting too technical), take a semi-auto with a 3" barrel and a round that lets say is 1" long and is chambered. Does that mean that the stated 3" barrel on the semi-auto is actually only 2" in real terms?
Bullets have Nothing to do with barrel length.
 
#20 ·
This sounds like a totally different subject, and really doesn’t come into play when all one wants to know is how to measure the length of a barrel, or how a manufacture designs a barrel. My original question was about how to measure the length of a barrel of a revolver. It had nothing to do with semi-auto barrels or where the round sits in relation to the barrel.

Out of curiosity, Glock says the G17 barrel is 4.49 inches long. I broke mine down and measured it. That measurement includes chamber and the feed ramp. Mmmm
 
#21 ·
Keep in mind that barrel length to be legal for hunting in some state's regulations may not necessarily be the same as barrel length as measured by manufacturers. In our state of Wisconsin, for instance, we need 5 1/2" barrel length to be legal for deer hunting, but barrel length is defined as length of the barrel from muzzle back to the firing pin. That allows you you to use "4-inch barreled" barreled revolvers, such as my GP-100, because you get to include the cylinder. On the other hand, a typical full size 1911 with a "5" barrel" is not legal.
 
#32 ·
Keep in mind that barrel length to be legal for hunting in some state's regulations may not necessarily be the same as barrel length as measured by manufacturers. In our state of Wisconsin, for instance, we need 5 1/2" barrel length to be legal for deer hunting, but barrel length is defined as length of the barrel from muzzle back to the firing pin. That allows you you to use "4-inch barreled" barreled revolvers, such as my GP-100, because you get to include the cylinder. On the other hand, a typical full size 1911 with a "5" barrel" is not legal.
I have to ask.........I am not a hunter, but do people hunt deer with a handgun?
 
#22 ·
The correct measurement IS take from the end of the barrel to the face of the cylinder period! Heck the cylinder gap is only about .006!
 
#25 ·
I measured the gap in my single six at 0.005. Gap seems pretty much immaterial when measuring barrel length, but it is part of the length, so I guess it must be part of that 6 ½ inches. :D

There you have it ... Gun History 101. There's a lot more but I don't want wingspar to get mad about being off topic.
Not upset about being off topic. I learned something interesting out of this about barrel lengths between revolvers and pistols, even tho pistols were not part of my original question.

Been off camping for a few days, hence, the slow reply. :)
 
#24 ·
Here's some "gun history" that might be of interest .... Prior to the Civil War, the most common handgun was a black powder single shot pistol. As technology advanced and revolvers were invented, gun manufacturers noted an interesting phenomena. A pistol with a non-vented barrel (measured from breach face to muzzle), delivered the same velocity as a revolver with a barrel of the same length that was measured from the front face of the cylinder to the muzzle. Primarily a sales gimmick, revolver barrels were measured from the cylinder face to the muzzle. This leveled the playing field between a pistol and a revolver, making muzzle velocity the same, even though they were measured differently. Seems there's always a reason .....

Later when modern cartridges were invented, the same concept applied. Turns out the B/C gap in a revolver vents quite a bit of pressure, which robs considerable muzzle velocity. An excellent example is a 45 ACP, which is chambered in both pistols and revolvers. In a 1911 with a 5" barrel, there is about 4" rifled barrel. In a 5" barreled revolver chambered in 45 ACP, the cylinder is about 2" long and the cartridge occupies about an inch, leaving about an inch of cylinder throat plus a 5" barrel for a total of 6" of bullet travel. So, the B/C gap loss makes the revolver chronograph very close to the same as an "equal length" pistol, assuming they are both measured properly. You can prove this concept by chronographing a 5" 1911 and a Ruger Blackhawk with a 4 5/8" barrel. With GI ball ammo (230 gr FMJ), the 1911 will chrono at about 850 fps, whereas the BH will chrono at about 830 fps with the same ammo, even though the BH has 1.37" more bullet travel. I measured my Ruger SR1911 barrel at 5.050" and my 45 BH at 6.42" (from breach face to muzzle) to get these actual numbers and have chronographed them side-by-side. I have also tested a 9mm 4 5/8" BH and a Beretta 92FS and got identical results.

B/C gap loss is about 1.5% for each .001" gap, no matter what cartridge is used ... so, an average revolver with a .006" B/C gap will lose about 9% of its muzzle velocity compared to an equal length non-vented barrel. The math works out where the B/C gap loss is compensated by the gain of the added bullet travel. So in a nutshell, pistols will chronograph virtually identical to equal length revolvers when shooting the same ammo.

The Gun Control Act of 1968 made some defined changes. First, all handguns used to be called pistols. BATF began requiring manufacturers and importers to report all guns manufactured or imported by type ... rifles, shotguns, pistols and revolvers. Pistols are defined as any handgun without a revolving cylinder. Obviously, revolvers are all handguns with a revolving cylinder. Along with these "official definitions" came the "official" way to measure barrel lengths. All rifles, shotguns, and pistols are measured from the muzzle to the breach face as had been the tradition for well over 100 years. Revolvers are measured from the muzzle to the cylinder face, which has also been tradition since revolvers were invented. If you look at Ruger's web site (or any other gun manufacturer), they always separate the two handgun categories ... pistols and revolvers.

There you have it ... Gun History 101. There's a lot more but I don't want wingspar to get mad about being off topic.
 
#26 ·
The method of measurement recommended by the Bureau of Alcohol, Tobacco and Firearms.

Here's a little info I thought others might enjoy.

KNOWING THE BARREL LENGTH OF YOUR HANDGUN IS VERY IMPORTANT WHEN SELECTING THE PROPER SIZE HOLSTER FOR YOUR GUN. A HOLSTER THAT IS TOO SMALL WILL NOT PROPERLY AND SAFELY CONTAIN THE HANDGUN AND ONE THAT IS TOO LARGE MAY ALLOW THE GUN TO SLIDE DOWN TOO FAR INTO THE HOLSTER FOR A PROPER DRAW.

ALL HANDGUN BARRELS ARE MEASURED FROM THE BREECH FACE TO THE MUZZLE END OF THE BARREL, BUT THE BARREL ON REVOLVERS AND PISTOLS IS MEASURED DIFFERENTLY.

Autoloading Pistol Barrel Length (semiautomatic pistol) The method of measurement recommended by the Bureau of Alcohol, Tobacco and Firearms is:

1. Unload the Gun.

2. Pull back the slide and cock the pistol, letting the slide close in the forward position.

3. Insert a dowel rod of appropriate diameter down the barrel of the gun until it stops at the breech face.

4. Mark the dowel rod at the muzzle end.

5. Remove the dowel rod and measure from the end of the rod to your mark. This is the barrel length.

This length may be closely estimated without a dowel rod by following this method:

1. Unload the gun.

2. Pull back the slide and lock it open.

3. Measure from the end of the barrel where the cartridge is inserted forward to the end of the muzzle, along the side of the barrel.

Revolver Barrel Length Measurement

1. Unload the gun.

2. Insert a dowel rod of appropriate diameter into the muzzle end of the gun.

3. Slide the dowel rod into the barrel until it touches the face (front) of the revolver's cartridge cylinder.

4. Mark the dowel rod at the muzzle end.

5. Measure the dowel rod from the end of the rod to your mark. This is your barrel length.
 
#27 ·
It's A.

Technically, there is only the Cylinder, and the Barrel in the descriptions of the revolver parts, and since they don't measure or count barrel/cylinder gap because it's air and not an actual part, then the barrel comprises 100% of the measurement from the muzzle, to the cylinder face.

The Talo revolvers have a 3 7/8" barrel, yet from the muzzle to the face of the frame is only 3" so the correct answer is still A.
 
#29 ·
:D
 
#34 · (Edited)
Yes, using hand guns for hunting has been around for a long time. Back in the mid 60s to late 70s, there was huge movement to use handguns for hunting and it greatly influenced me at the time, since I was just starting to hunt deer. My first ever "deer rifle", in fact, was a Ruger Super Blackhawk 44 mag. Took my first two deer with that single action, stalking to get close. That was back in the day when hunting from tree stands was just beginning to get popular. A lot has changed in deer hunting since then.
 
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