How is barrel length measured? Bolt face to muzzle, or some other datum points?

Bolt face to muzzle, with the bolt closed.

quote:

Bolt face to muzzle, with the bolt closed.

Unless you were Rocky Gibbs he went front of the bullet to end of the barrel. His 24" barrels were more like 27".

quote:

Originally posted by ramrod340:

quote:

Bolt face to muzzle, with the bolt closed.

Unless you were Rocky Gibbs he went front of the bullet to end of the barrel. His 24" barrels were more like 27".

That is usually thought of as "bore" length. For instance, the Powley Ballistics Calculators considered "bore length" as that distance from the base of the seated bullet to the muzzle. However, for legal purposes, BATF measures barrel length as stated above, from the face of the closed bolt to the muzzle. From the manufacturers standpoint, their barrel lengths are measured from end to end, breech to muzzle.

As above (BF to Muzzle) with one cravat.

IF the chamber is separate from the barrel (IE a revolver), than it's the length of the barrel only (including the part threaded into the frame), but NOT including the chamber (cylinder) length

I asked the question as a result of reading about the Houston Warehouse. There they determined that 21 3/4" was the magic length for optimum accuracy. That was in bench guns. I doubt if it would apply well to magnum caliber rifles, at least for overall performance.

Whatta ya bet the feds would measure from the receiver shoulder to muzzle?

Same as on any self-loading pistol, or any other closed breech firearm, from the point of ignition (bolt or breech face) to the muzzle end.

Easiest way is to slip a cleaning rod down the barrel, mark the part that is level with the muzzle end and measure it!

quote:

Originally posted by Brice:
I asked the question as a result of reading about the Houston Warehouse. There they determined that 21 3/4" was the magic length for optimum accuracy.

For which load?

There are way too many variables involved to pick the optimum barrel length for a given cartridge. You can work up an optimum accuracy load for a particular barrel, but change one element with the load, and all bets are off. Remember this, regardless of barrel length or caliber, no two barrels are the same.

The Houston Warehouse was primarily short range BR guys. They were shooting 22cal and small capacity 6mm rounds. Most competition BR barrels are about 22".

WOW.. hadnt even thought about the warehouse in years

It would take a lot of very well controlled
shooting to show that 21 3/4 was more accurate
than 22.

I'm not at all sure that they "proved" that 21-3/4" was perfect. One of the more accomplished warehouse shooters advanced the notion and there seemed to be consensus. Just out of curiosity, does anyone know approximately what sort of pressures the benrest crowd run? Is there much diffference between the 22's and the sixes?

It has been said that some are running the 6PPC at around 70,000. If some can calculate it, figure 30.5+grains of V133 and a 68grain bullet.
Most 6PPCs run at about 3360 and the short 22PPCs run about 3560.
I think the 95% that use the 6 do so because of a lot less amount of case prep. It is a chore to shorten the brass .100" when it is only good for one weekend of shooting.

70K, Eh? That's getting right up there. Thanks for the info.
Brice