Barrel Lengths {Myth Buster}

[USSR]

Where does the article say anything that could be characterized as meaning this: "When you are talking about making a rifle more accurate by simply lopping off a few inches..."

Marines reporting excellent accuracy that was comparable to or exceeded that of their M40s...

All this from a rifle that the author admitted only generated "2,440 fps from his 16-inch barrel...". I've shot enough at 1,000 yards to realize that a match-grade rifle shooting a bullet 200-250fps slower than a comparable rifle, is at a distinct disadvantage.

It is not a simple matter of less velocity only affecting elevation, as the velocity decreases, also will the projectile behave differently in regards to windage.

Yep. I've seen what happens on target when bullets go transonic, and it ain't pretty score-wise. We like to send 175SMK's at 2600+fps bare minimum, and I would tell a guy shooting them at 2440fps at a 1,000 yard match to leave that load at home. So, a gun writer who simply states in long range use "Marines reporting excellent accuracy that was comparable to or exceeded that of their M40s" with a 175SMK at 2440fps, simply doesn't pass the "smell" test. Just MHO.

Don

 

[Art Eatman]

This is a "seems to me" thing, and I'll ignore super-quality manufacture and comparative stiffness of the receiver group:

Factors involved include such things as the curve of pressure vs. time of the burning of the powder. Another is the harmonics of the barrel. Somewhere in this is the relationship between barrel length and bore diameter, although I have no clue about how to consider this.

Past efforts appear to indicate that bores between 0.2" and 0.3" work best. If there is a relationshipe between length, vibrations and powder burn time, it would appear that barrels of approximately 22" are a better compromise. That is, a longer barrel might be better from the standpoint of powder burn, but less so for vibrations. Maybe.

I give some credence to the Houston warehouse article since the people involved were nit-picky customizers and I guess you could call them professional-level shooters. It was not some sort of one-time event, either.

Results from rifles of various barrel lengths which are just "off the shelf" can vary all over the place, so I don't think that comparing them is valid when considering length vs. group-size capability.

So I dunno. I get sub-MOA from a 19" .243, and sub-MOA from a 26" .30-'06. Maybe that's why I don't worry about it very much.

 

[JohnKSa]

USSR,

Saying that 2 VERY different rifles exhibit similar accuracy even with different barrel lengths is not even close to the same thing as saying you can make "a rifle more accurate by simply lopping off a few inches..."

So, a gun writer who simply states in long range use "Marines reporting excellent accuracy that was comparable to or exceeded that of their M40s" with a 175SMK at 2440fps, simply doesn't pass the "smell" test.

I don't disagree. It is hard to swallow that a bullet that doesn't remain supersonic to the target is going to group well at that distance. What I was referring to when I said you were tilting at a strawman you created yourself was your quote that : "Ah, so a heavy contour 16" E.R. Shaw barrel will outshoot a 26" MTU contour Krieger, simply because it is shorter?" The article doesn't say anything like that and neither has anyone on this thread.

I give some credence to the Houston warehouse article since the people involved were nit-picky customizers and I guess you could call them professional-level shooters. It was not some sort of one-time event, either.

I give it a lot of credence, I'm just skeptical about someone saying that the most accurate barrel length across the board is 21.75", period. I can see that number being a good starting point for building an accurate rifle that chambers a cartridge that's within the range of cartridges commonly used in benchrest, but saying that it's the most accurate barrel length, bar none, no other qualifications needed, is hard to accept...

 

[zfk55]

Well, I'll let this one go, but understand that the man has been making contract rifles of this sort for private security with most in the far east since 1999 and making a darned good living doing it with repeat business from those agencies.
After a 10 year wait I now have one and it performs exactly as he said it would.
Besides his contract rifles he's also the head of E.D.M.'s field training for long range Cheytac and .50 shooters. Whatever your educated opinion might be, Wilson is the real deal and I have the rifle that proves it to me, and that made it worth the wait.

zfk55

 

[glockmon]

If you look at a long barreled rifle say... a 26" in super slow motion you'll see that it flops up and down like a wet noodle when the rifle is fired . So true accuracy of the longer depends on if the barrel is wobbling up, in the middle or down when the bullet is leaving the barrel. Therefore shorter barreled rifles tend to be a bit more accurate than the longer ones due to lack of.

 

[Art Eatman]

glockmon, no big argument, but it seems to me that the larger issue would be consistency of the vibrations from shot to shot. I can see where it might be easier to achieve this with a shorter barrel, but that doesn't mean that it's not possible with a longer barrel.

 

[zfk55]

Art, this particular rifle has the following specs:

She has a custom, internally re-machined Armalite AR10 receiver/magazine well cut to accept a slightly longer AR10 custom magazine, this because of the required OAL.
All internal receiver areas are coated with a Tungsten Disulfide Matrix derivative. The chamber and throat are cut to accept one projectile profile only. The Sierra 175 MK, and no other. Because of these cuts the TTL, seat depth and OAL are specific and critical, thus the need and reason for a custom machined Mag-well.
Walther 17-4 S/S barrel, internally tapered .006 electro-polished bore and a 1-10 ROT.
SWS foregrip and a prototype trigger from his inventory that later evolved into the Chip McCormick trigger.


zfk55

 

[glockmon]

I agree ART, I was just pointing out a bit of info. I " WAS " looking at a Savage 110 FCP-K in 300 Win. Mag. 24" but, since last week, Savage has changed their website and removed that model from their line up. SO, the only one close to it that I can see is the 111 Long Range Hunter 26" which costs more and is 2" longer. Or the Winchester Model 70 Ultimate Shadow. I'm kinda torn now. Leaning towards the Savage though. I'm still browsing around.