Barrel Length Measurement...

[BCB]

I never really gave this much thought, but how do you measure the length of the barrel on wheel gun?...

Is it from the actual beginning of the barrel in front of the cylinder to the end (muzzle)?...

OR, is it from the back of the cylinder to the end of the barrel (muzzle)?...

I need this info to plug into QuickLoad and it is certainly relevant as I see the velocities this program is predicting for a given charge, bullet, and barrel length…

Thanks…BCB

[454PB]

Forcing cone to muzzle.

[pietro]

.

The surest/easiest way to measure a revolver's bbl length is to rotate the cylinder so that one of the webs between the chambers lines up with the bore, then drop a dowel or other rod downbore until it hits the web, mark the rod at the muzzle, withdraw the marked rod & measure it to the mark.


.

[al bundy]

Is it from the actual beginning of the barrel in front of the cylinder to the end (muzzle)?...
Thanks…BCB

yes, this is correct

[44man]

Except BFR's where it is measured from the front of the frame. I like it since the forcing cone is not barrel. I like the longer barrels anyway.

[jwp475]

Except BFR's where it is measured from the front of the frame. I like it since the forcing cone is not barrel. I like the longer barrels anyway.


BFR did measure them that way with the over the counter guns, not on the custom shop guns. They now measure both correctly from the forcing cone to the muzzle. Forcing cone is considered part of the barrel.

[Rick Hodges]

BFR did measure them that way with the over the counter guns, not on the custom shop guns. They now measure both correctly from the forcing cone to the muzzle. Forcing cone is considered part of the barrel.
Yep! That's the way I was taught to measure them.

[BCB]

“OR, is it from the back of the cylinder to the end of the barrel (muzzle)?...”

That was a line from my original post…

I was asking this question so I could fill in the info needed for the QuickLoad program…

Upon further reading of the manuals that come with the program (they are lengthy and fairly intense to read), I learned that for the use of the QuickLoad program, it is as quoted above…

They use total length from the head of the cartridge to the end of the muzzle. The program then calculates the actual distance the bullet travels by knowing the location of the base of the bullet in reference to the end of the muzzle. It can calculate the base of the bullet location from the O.C.L. and the length of the bullet…

An interesting, and somewhat complex and a bit complicated, program for sure…

Thanks…BCB

[jwp475]

“OR, is it from the back of the cylinder to the end of the barrel (muzzle)?...”

That was a line from my original post…

I was asking this question so I could fill in the info needed for the QuickLoad program…

Upon further reading of the manuals that come with the program (they are lengthy and fairly intense to read), I learned that for the use of the QuickLoad program, it is as quoted above…

They use total length from the head of the cartridge to the end of the muzzle. The program then calculates the actual distance the bullet travels by knowing the location of the base of the bullet in reference to the end of the muzzle. It can calculate the base of the bullet location from the O.C.L. and the length of the bullet…

An interesting, and somewhat complex and a bit complicated, program for sure…

Thanks…BCB

that would be correct in my opinion with a rifle or pistol barrel, but not a revolver barrel.

[BCB]

I sort of wonder the same as there is a nice space between the front of the cylinder and the forcing cone...

Probably would break the continuity of the pressure curve...

Oh well, I reckon QuickLoad knows what to ask...

Thanks...BCB

[Groo]

Groo here
For hunting the barrel of a revolver is from the front of the cylinder to the end of the barrel.
For autos and single shots it is from the breach to the end of the barrel.

[Idz]

From the case head is what QuickLoad uses. It assumes any loss through the gap is small enough to ignore. That may be one reason why it works better for rifles than revolvers. QuickLoad also ignores primers, leade, rifling and other things and approximates those factors. For $150 you can't expect a supercomputer program. If you are deluded you can fiddle with some parameters to match your chronograph data but I sure wouldn't believe the resulting pressure curves.

[44man]

BFR did measure them that way with the over the counter guns, not on the custom shop guns. They now measure both correctly from the forcing cone to the muzzle. Forcing cone is considered part of the barrel.
My custom shop JRH measures 8-1/4" from cylinder front. I ordered 7-1/2". But I have had it a few years so I don't know what they do now. I actually liked the longer measurement.

[theperfessor]

What Quickload uses and what the BATFE uses are two different things!