Barrel length question for the Guru's
 

The standard barrel length varies depending on the cartridge in question. For example a .30-06, .270 Win., etc are usually 22 inches. The magnums (7mm Rem, .300 Win, etc) are typically 24 inches. I was just wondering what the extra 2 inches meant in terms of performance, accuracy, velocity, etc.

The reason I ask is that I see alot of guys complain about the 24" barrel on the mags. It occurred to me that taking the barrel down to 22.5-23" and re-crowning it might not hurt performance at all.

So whats with this barrel length stuff anyway??

RE: Barrel length question for the Guru's
 

It's a simple concept. All barrel lengths chosen are (like most things) a compromise between weight, handiness and technical issues. In the case of barrel lengh, standard cartridges don't need such a long barrel as magnums....as they carry less powder. A longer barrel for the magnum loads allows more of the (large) powder charge to be burnt...thus propelling the bullet to the higher velocities for which magnum loads are designed. With this in mind, it is almost always true that a magnum cartridge will suffer a greater loss of velocity from a shortened barrel...than will a standard cartridge. For example, if you compared a .308 Win.....and a .300 Win. Magnum....the .308 would usually get a 22" barrel (actually, a 24" barrel might be better....but 22" is a compromise). The .300 Win Mag needs at least a 24" barrel (even 26" to 28" would be better...again, it's a compromise), to extract all of the performance of which it is capable. If you were to cut the .308 barrel to 20"....and the .300 Win. Mag barrel to the same length.... the Magnum round would lose much more performance (over that of a more standard barrel lengh)....than would the .308. This is why most magnum rifles come with at least a 24" barrel....and often, a 26" one. Many custom magnum rifles come with barrels even longer than 26".

By the same concept, there is a maximum length, above which additional velocity is not worth the extra weight and unwieldyness. For standard rifle cartridges, anything longer than about 24" offers little advantage (and indeed, most ammo companies use 24" test barrels for their standard cartridges). For magnum rounds, often 26" is the standard test barrel length....but, not much would be gained from going beyond 28"...

I hope that this explanation will help clear the mystery.

RE: Barrel length question for the Guru's
 

Gorse got most of it. The magnums, and some standard cartridges use the slower burning powders too, and so need the longer barrels.
One of the things I like about a 308Win. is you can use a little shorter barrel without losing much velocity. I read an article by Finn Aagaard some time ago in which he cut
the barrel of one of his 308s down. He lost approx. 30fps cutting it to 20", but when taking it down to 18-1/2" the avg. loss was about 75fps.
Personally, I'd like to see 21" barrels on standard cartridges, and 23" on magnums.
Carbines at 19.5" (18.5 is a little too short).

RE: Barrel length question for the Guru's
 

Thanks, I think that pretty well covered my question... I was looking pretty close at the Sako 75 stainless in 7mm Mag and noticed the barrels are listed at 24 and 3/8. This got me wondering about barrel length vs velocity....

Thanks again

RE: Barrel length question for the Guru's
 

I hate barrels less than 24 inches and I much prefer 26 inch. I can always trim a barrel back a bit but once they are to short then theres not much you can do about it. I like to be able to obtain the highest velocity without hot loading a cartridge.

RE: Barrel length question for the Guru's
 

JamesB,

Point taken. We can always shorten 'em. Little hard to "stretch" 'em.
Looks like Remington has been listening to ya'. Their barrels seem to be getting longer.