Thread: Where to measure barrel length?

So my .223 has an 18 1/2" barrel if I measure from the muzzle to where the barrel fits flush with the receiver (wouldn't include the chamber).

However, if I measure it from the muzzle to the bolt face it is 20".

Which is the correct measurement to use?

Bolt face to muzzle.

Originally Posted by Magnetite

Bolt face to muzzle.

This is correct.
It is quite a bit shorter than the barrel looks. For instance, the OAL of a .308 cartridge is 2.800" (therabouts) so a 20" barrel will only have about 17" of rifling and bullet travel. For instance, the thread attaching the barrel to the receiver is part of the barrel length. It can be hard to locate the bolt face as its usually some way back inside the receiver (except in the SMLE or break action rifles).
Have a look on some barrel makers web sites eg Welcome to Shilen Rifles, Inc.

Its super easy on actions that have an excess gas port on the side which aligns with the bolt face

Sent from my SM-G930P using Tapatalk

Good to know! I always wondered what the correct method was

It's pretty easy measurement to take. With the bolt closed, drop a cleaning rod down the barrel, use tape to mark the muzzle, measure length of rod from tape to end.

Originally Posted by Dama dama

It's pretty easy measurement to take. With the bolt closed, drop a cleaning rod down the barrel, use tape to mark the muzzle, measure length of rod from tape to end.

Then subtract the length of the ammo measured with a comparator, this gives you the length of the rifling

Now you can see why the short mag (saum) looks so efficient in a short tube compared to long action cartridges, say 270 or rem mag

The inch shorter short mag ammo gives you an extra inch of rifling (more velocity)

A fact very often overlooked

The “efficiency” of a case really only exists on the internet, and has little practical application once you step outside.

Originally Posted by 7mmsaum

Then subtract the length of the ammo measured with a comparator, this gives you the length of the rifling

Now you can see why the short mag (saum) looks so efficient in a short tube compared to long action cartridges, say 270 or rem mag

The inch shorter short mag ammo gives you an extra inch of rifling (more velocity)

A fact very often overlooked

The “efficiency” of a case really only exists on the internet, and has little practical application once you step outside.

Yep exactly.

Originally Posted by 7mmsaum

Then subtract the length of the ammo measured with a comparator, this gives you the length of the rifling

Now you can see why the short mag (saum) looks so efficient in a short tube compared to long action cartridges, say 270 or rem mag

The inch shorter short mag ammo gives you an extra inch of rifling (more velocity)

A fact very often overlooked

The “efficiency” of a case really only exists on the internet, and has little practical application once you step outside.

Does one in h really make that much if a difference? In my limited experience it seems like the

Sorry meant to say does 1 inch really make that much if a difference? Or is this specific to short barrel set ups?

It depends on the individual rifle. You will get as much variation between the same rifle with the same length barrel than the difference an inch shorter barrel might give, till you start getting down to 16 inch barrels and less.

You measure a barrel from muzzle to the bolt face. Barrel measurement includes the chamber. (So yes - technically a the 22'inch barrel on a .270 is shorter than the same .22'barrel on a .308.)

Originally Posted by Rated M for Magnum

Sorry meant to say does 1 inch really make that much if a difference? Or is this specific to short barrel set ups?

ask your woman......... sometimes an extra inch would be very desirable...all depends on how many inches you have to begin with I guess.

Originally Posted by Micky Duck

ask your woman......... sometimes an extra inch would be very desirable...all depends on how many inches you have to begin with I guess.

2 is better than one ay?