When someone states a barrel is 24" long, is it measured from the bolt face to the muzzle, the rifled length of the barrel, or from the muzzle to the front of the action? What is the accepted norm?

------------------
Gerard Schultz
GS Custom Bullets

Gerard,

I can say that the official, BATF way of doing it is to measure from the closed action bolt face to the edge or corner of the crown of the barrel where the rifling stops.

From the middle of the front ring is usually the way barrels are measured in the USA, for all practical purposes...

legal measurement would be from the bolt face to front edge of the crown, squared off.

------------------
Ray Atkinson

ray@atkinsonhunting.com
atkinsonhunting.com

It's from the bolt face. The easiest way to measure it is to insert a cleaning rod down the muzzle on a closed action (empty of course) until it hits the bolt face then mark the rod and measure.

I nearly always use a tape measure. (Sorry, can't pass up a perfect wise ass comment.)

End of the breech to the end of the muzzle. In a revolver, end of the barrel, face of the cylinder out to the muzzle.

For BATF legal, end of the breech to the muzzle. If you're trimming down your shotgun or rifle to the legal limit, allow about 1/2" so that when the Feds freeze the barrel in nitrogen and measure it with a red hot ruler, the contracted, cold barrel is still legal. (Being a wise ass again.)

------------------
This Space For Rent.

Another argument in faor of short-action cartridges...you get more rifeling to work with.

Genghis,

Works for me

Thanks all for your replies. I am a bit confused though. Genghis, why does the BATF freeze the barrels when they measure them? Also what is the purpose of heating the measuring device? It must be difficult to handle at such elevated temperatures and any gain in measurement will be very small compared to the inreased difficulty of the process.

If I can offer some advice on your difficulty of passing up a a wise ass, if you apply lateral thinking, possibly you could pass down? Maybe I do not understand your predicament and my advice is out of line. Seeing as though you work for MC, maybe he can help.

------------------
Gerard Schultz
GS Custom Bullets

I usually measure,then multiply by 4,then divide by eight,then multiply by two.

...no sqare roots ?

Square roots aren't necessary but you can't get by with out cosines.

O.K. wise guys, tell us why Gerard wanted to ask this question, in the first place. Everyone knows it is breech/boltface to muzzle. What ulterior motives might he have?

------------------
Rifles And Bullets r us: RAB

An alternate method seems to work just about as well.Sometimes I measure from the bolt face to the target after which I measure from the muzzle to the target.I then subtract the former from the latter.

Correction/I subtract the latter from the former.

Gerard, you should no better than to ask a bunch of guys how to measure how long something is. If they tell you their barrel is 24" inches long, they're probably are exagerating by at least two inches. For an accurate measurement get a woman to measure your barrel.

But sometimes I forget and carry the rifle with me to the target and have to start all over again.

Jagtip,
I know how that happens. I think a lot about the herafter lately. I walk into a room at a brisk pace, stop, and think "Now what did I come here after?"

I am following this thread very closely and in consultation with a number of astute ballisticians, will in due course present the definitive method, accompanied by the required formulae, for determining the length of a barrel.

------------------
Gerard Schultz
GS Custom Bullets

That explains the looks I would get when I took my rifles to the Sheriff department for a handgun safety inspection. We always measured the portion extending from the non metal end of the stock's fore end to the muzzle. This would really create a dilemma when a metal capped Mannlicher stock would be brought in. The Sergeant would always gather the Deputies around when we would state that our rifle had a 0" barrel but shot great groups at 100 yards! I always thought that the tears they got in their eyes was a result of me not showering the morning of the inspection. Now I know they were just pulling a FUNNY ! !

"How do you measure . . . ?"

I think that in all of the above posts two important related factors have been omitted.

1. We must all agree to measure barrel lengths with the firing pin in "cocked" position. Otherwise the dowel might rest on the protruding pin and thus give a false measurement.

2. Measuring with a dowel down the barrel can be a very dangerous proposition and must be done following all known guidelines of gun safety, or injuries to the measurer or his witness may occur. "How?"you ask. It appears that the dowel could easily be forcibly expelled from the rifle in question unless said rifle has been made secure by the applications of its inherent safety device. One careless pull of the trigger could release the firing pin which could act on the dowel in a very detrimental way.

BigBores,

I respectfully disagree with your "BATF" barrel length definition. Particularly "to where the rifling stops." How then would we measure smooth bores and shotguns? Also, while following "A.R.15.com" it was revealed that many AR15 owners with 12.5"barrel lengths would permanently attach 4" muzzle breaks/flash-hiders to comply with the BATF 16" requirements. Thus Ray's definition would be closer to the truth, but still not legally accurate.

Gerard,

I hope you will publish the results rather than merely give an oral presentation at some obscure meeting in some obscure location in SA as many of us here need to have the facts presented in black and white before we will believe them. Of course, we (I think I can speak for all of us here on the board) will be eternally grateful for bringing this highly controversial subject matter to our attention and consequently its ultimate closure.

Furthermore, in your highly esteemed opinion, do you think this topic would make a suitable subject for a doctoral/masters thesis? DOBL (Doctor of Barrel Length) at the college of gunsmithing?

For certain, your post will give many of us here better and more restful nights as we will no longer be pacing the floors of our kitchens at midnight holding a cup of coffee in one hand and smoking a cigarette with the other while ponderng the big question.

At last someone here dared to broach the topic!

Herb D

P.S. Shoud we all agree to measure barrels at a predetermined time, temp.,altitude, latitude, moon phase, etc.?

What a person won't do on a rainy Monday afternoon!

[This message has been edited by Herb D (edited 11-20-2001).]

Gerard do you work for the BATF & are just testing us?

------------------
NRA Life member

Herb,

I respect your disagreement, and I respectfully disagree with that. (?)

As far as when I added the rifling stops description it was in reference to which part of the crown, speaking of the inner corner of the crown. This was to imply that the barrel is measured from the inside, not the outside. I should have been more clear.

As to the 12.5" AR15 owners using 4" muzzle breaks, I think they are skirting a grey area of the regs. I used to work at a gunshop, and was required to brush up on some of the many, many regs in the BATF rulebook, which I would do during "lull" periods, ie no customers in the store. I do quite clearly remember that BATF calls the "crown" on a rifled firearm that portion of the barrel where the rifling stops. Flash suppressors and muzzle breaks do not count towards the official barrel length, even if they are not removeable, unless they are also rifled. So for example, on the Springfield M1A, with the flash suppressor, even though it is a fixed part of the barrel, it does not count towards the official BATF version of a barrels length. Looking at your AR issue, I do not know how they are getting around it. I believe you that it is happening, I just don't know how. Maybe I do have it wrong, I was pretty sure though. Maybe someone with a copy of the BATF regs can look it up?

------------------
"A strong body makes a strong mind. As to the species of exercise, I advise
the gun. While this gives moderate exercise to the body, it gives boldness,
enterprise and independence to the mind. Games played with the ball and
others of that nature, are too violent for the body and stamp no character
on the mind. Let your gun therefore be the constant companion of your walks."
Thomas Jefferson