does a longer (handgun) barrel allow for higher accuracy?

[Midget]

i'd long thought that a longer barrel on a handgun (or rifle, for that matter) would allow for the weapon more consistancy in shot placement. it just seemed reasonable. of course, number of turns, type of bullet, weight, distance between sights, etc., all play a role in the dynamics of a bullets travel, but it still seems like longer barrel = better accuracy. am i completely wrong in this assumption?




because i today i did a bit of informal science and compared my ruger GP100 6" barrel vs. my ruger SP101 3" barrel. i fired 158gr SWC lead rounds in .38SPL, bench rested and sitting at ~15-20m and what i found was that the shotgroups from either revolver were more or less similar. i expected the SP101 to fire more sporadically and in less-tight a shotgroup. you'd think that extra 3" of barrel on the GP100 would make a difference, but not discernably so on todays outing. perhaps i'm not shooting at far enough of a distance?


certainly, the GP100 made recoil more managable due to weight, and the sights are adjustable, and in a way having a longer distance between sights helped aiming.


but all in all, i'm very impressed with the performance i've pulled out of my little SP101, and i'm feeling sheepish at having wasted extra cash on a new 6" revolver that may not have any merit over my original 3" revolver.


any thoughts? i wish i'd had taken pictures.

 

[mete]

It doesn't effect mechanical accuracy to any degree but it does improve practical accuracy as it gives you a longer sighting radius.

 

[xbxb]

not for the gun but it probably will for you

 

[Matt Shade]

I think that all other things held constant, the length of the barrel doesn't really affect accuracy.
If you have equally tight chambers, good rifling, and crowns, the bullet flight should be pretty much identical.
Comparing two rugers like that is a very good way to demonstrate this. Both guns have rather heavy barrels for their length, so harmonics isn't much of an issue. They pretty much have a bull barrel. And given that they are from the same manufacturer that has pretty consistent quality, you should have similar specs on everything else. You shot them from a position that allowed you to shoot them equally well, and so you got very similar results from them both.

In more practical type shooting, the longer barrel probably would get the edge simply for the fact that it has a longer radius between the sights, as you already mentioned. It makes aiming easier. Put a scope on and that goes away. The longer barrel usually uses powder more efficiently and gets more velocity out of the same load which can cut down on the amount of holdover required. This makes it seem more accurate at longer distances, when the other barrel may group just as well only lower on the target.

There are a lot of variables that have to be looked at though. A rifle with a long whippy sporter weight barrel may not group as consistently as one with a shorter stiffer barrel.

All in all, accurate guns are more fun and it sounds like you have a good carry peice in either revolver with those two.

 

[richard j]

i have a ruger standard model 22 pistol with a 6" barrel. i was at my friends gun range shooting at clay pigeons which were set out at 100 yards. i was then picking off the pieces. i was at another friends place shooting at his rifle target which was at 300 yards. there was a railroad tie plate attached to a tree along with his other targets. i could hit that tie plate 7 out of 10 times i could shoot dime size groups of 10 rounds at 40" consistently. some guns are exceptional shooters no matter if its a rifle or pistol. i would have to say it depends on the shooter and the gun.

 

[ironraven]

Along with a longer sight radius (and sometimes just better sights available from the factory), the longer the barrel (within reason) the higher the muzzle velocity becuase you are able to make more effective use of the still expanding gases. That generally leads to a flatter trajectory.

 

[David E]

Along with a longer sight radius (and sometimes just better sights available from the factory), the longer the barrel (within reason) the higher the muzzle velocity becuase you are able to make more effective use of the still expanding gases. That generally leads to a flatter trajectory.

Not necessarily true. There are other factors that can affect velocity besides barrel length. It's not unheard of for a 4" barreled revolver to have higher velocity than an otherwise identical 6" revolver.

Things like true bore diameter, flash gap, cylinder throats and adversely affect accuracy.

But, even if a 6" gave you 100 fps more, that alone doesn't make it more accurate. It might allow the shooter to make hits at unknown ranges just a little easier due to the slightly flatter trajectory, but once you're dialed in with a 4", the groups would be pretty much the same.

Said another way, if I were to bolt each gun into a Ransom rest and then just showed you the targets, you wouldn't be able to tell which gun shot which group.

.

 

[SIFU1A]

you can put 2 pistols in a machine rest one w/a 3" bbl and one w/a 6" bbl and they should be about (if not almost exactly) the same as far as accuracy goes..

the longer bbl only helps the shooter be more accurate not the pistol.

 

[BlueyM]

Well, color me surprised.
I always took it as gospel truth that a longer barrel meant better groups.
Disregarding sight radius, would, say, a 2" barrel snubby .357 revolver be as accurate as a 8" barrel revolver, all else being equal?
(BIG difference in barrel length)

 

[mwerner]

Way back in '65 or so, stationed in Germany, I bought my first "serious" handgun-a Colt "detective special" in .38 special. (already planning for my law enforcement career)

I had read Elmer Kieth's "Sixguns", and his ideas on long-range shooting. On one of our trips to the range, I set up a paint can at 100 yards and assumed the recommended sitting position with the little thing.
I was surprised to see I could knock that paint can around quite nicely, thanks. Not only that, with the sun behind me, I could see those slow 158 gr. RN lead bullets going downrange!

 

[Midget]

whoa... you can hit a paintcan at 100 yards w/ a detective special? that's insane!


i took my dad's colt detective special to the range a while back and shot miserable shotgroups at only 5 meters. what's this recommended sitting position you speak of?




i'm curious about blueym's question as well-- next weekend i'll take out my S&W 360PD (1 7/8") and compare it to my 6" and see how they fare together.

 

[mwerner]

The technique Keith talks about is to sit with your back supported against something, and to support your forearms against the inside of your knees. This gives a very stable position similar to a bench.

The technique of long-range shooting with a handgun is not to use a standard sighting picture. Instead, you "hold up" progressively more of the front sight in the rear notch as range increases.
This is by-guess-and-by-golly for the most part, unless you have special sights made up as Keith did with contrasting bars of metal across the front sight to use as a gauge of sorts.
My old Smith & Wesson M27 had the "red insert" front sight that was popular back then, and I found I could use the edges of the red insert for this purpose.

Though long out of print (available from dealers on Amazon for as much as 75.00!), this book should be available from most good libraries.

 

[Bronco]

Disregarding sight radius, would, say, a 2" barrel snubby .357 revolver be as accurate as a 8" barrel revolver, all else being equal?
(BIG difference in barrel length)

When looking at a 2" vs. 8" barrel, you're taking the barrel length vs. accuracy comparison to a bit of an extreme. A 2" barrel is really short. Remember that there will be slight variations in the distribution and burn rate of the powder as the round travels down the barrel. This will lead to slight pressure differentials within the chamber, which in turn means that the expanding gases will not be exerting the exact same amount of force against all points on the base of the bullet. For nearly any reasonable barrel length, there is ample time as the bullet travels down the barrel for these pressures to equalize and thus provide more a uniform push against the bullet. But for super short barrels, the effect of these pressure differentials (even to include the possible presence of powder that has not yet had time to burn at all) could potentially lead to a very slight destabilization of the bullet at the critical moment it exits the crown of the muzzle.

This only speaks to inherent accuracy differences, though. We can easily specify that "all else be equal" as you have done. But, in practical terms, all else rarely, if ever, is equal. As has been mentioned, the increased sight radius gives a huge accuracy advantage to the longer barrel. What hasn't been mentioned, however, is that it's necessary for the shooter to develop a consistent method of holding the pistol so that he may be able to fully realize this advantage where it matters at the target. The longer barrel also means that the effects of recoil will have a longer time to cause the muzzle to rise before the bullet has exited the barrel. This effect can be easily countered by adjusting your sights or aiming point provided that the pistol is recoiling in exactly the same manner with each shot. Thus it is critical when using a long barreled pistol that you develop a consistent method of holding the pistol and a consistent way of allowing the pistol to recoil in your grip once fired.

 

[ironraven]

David, you are correct, other factors come into play. But if have two barrels of the same age and manufacturer, bored and rifled on the same machines, with the same degree of wear, after firing two or three hundreds of the same load and lot of ammunition through each, you will find that your velocity will be higher from the longer one. If you want to factor in additional variables, then we have to decide were to stop- I assumed that the handguns would be firing massed produced ammunition of quality manufacture, from barrels and chambers that were dimensionally identical in respects, and having the same cylinder gap. But the additional factors you want to add to things can vary between barrels produced on the same machine within an hour of each other.

And accuracy does have to do with velocity- it effects how quickly the bullet drops. It doesn't have as much effect on the group size (precision), but it will effect how far above or below point of aim you impact. Confusion between accuracy (how close to your point of aim) and precision (how close your results are clustered) is a common mistake.

 

[MORIMOTOM]

It doesn't effect mechanical accuracy to any degree but it does improve practical accuracy as it gives you a longer sighting radius.

all things being equal, a longer barrel will be more accurate than a short barrel.

as mentioned, sight radius and muzzle velocity are the key physical factors.

psychologically, one would likely be more confident with a longer barrel as well.

 

[UffDa]

I has been proven over and over that the length of a barrel has little effect on the mechanical accuracy. As has been said a few times in this thread, a longer barrel gives a longer sight radius which makes it easier to shoot.

Bob Munden shoots his handguns at 200 yards in one of his demos. First he pops a balloon with a .44 magnum with a long barrel then he does the same thing with a 2" S&W model 60. (I think he gave the poor thing a hernia.) Munden does this for a living, but if the Model 60 didn't have the accuracy to hit the balloon at 200 yards, it wouldn't make any difference how good a shot you are.

In my younger days, I used to be able to walk a can from 25 yards to 100 yards with my Chief Special. Now, I can't even see the can at 25 yards, but that's another story.

 

[MORIMOTOM]

I has been proven over and over that the length of a barrel has little effect on the mechanical accuracy. As has been said a few times in this thread, a longer barrel gives a longer sight radius which makes it easier to shoot.

Bob Munden shoots his handguns at 200 yards in one of his demos. First he pops a balloon with a .44 magnum with a long barrel then he does the same thing with a 2" S&W model 60. (I think he gave the poor thing a hernia.) Munden does this for a living, but if the Model 60 didn't have the accuracy to hit the balloon at 200 yards, it wouldn't make any difference how good a shot you are.

In my younger days, I used to be able to walk a can from 25 yards to 100 yards with my Chief Special. Now, I can't even see the can at 25 yards, but that's another story.

yes of course. the barrel length in and of itself is incidental. good point.

having good fundamentals is what makes a shooter skilled.

 

[MORIMOTOM]

I has been proven over and over that the length of a barrel has little effect on the mechanical accuracy. As has been said a few times in this thread, a longer barrel gives a longer sight radius which makes it easier to shoot.

Bob Munden shoots his handguns at 200 yards in one of his demos. First he pops a balloon with a .44 magnum with a long barrel then he does the same thing with a 2" S&W model 60. (I think he gave the poor thing a hernia.) Munden does this for a living, but if the Model 60 didn't have the accuracy to hit the balloon at 200 yards, it wouldn't make any difference how good a shot you are.

In my younger days, I used to be able to walk a can from 25 yards to 100 yards with my Chief Special. Now, I can't even see the can at 25 yards, but that's another story.

yes of course. the barrel length in and of itself is incidental. good point.

having good fundamentals is what makes a shooter skilled. if one took a handgun with a two inch bbl, but extended only the sight radius another six inches, they would likely shoot far more accurately. in theory.

 

[GarageBoy]

A round that comes out of a longer barrel, assuming everything else equal, will come out faster, and have more energy no?

 

[MORIMOTOM]

A round that comes out of a longer barrel, assuming everything else equal, will come out faster, and have more energy no?

depends on the difference in bbl length. at some point you reach diminishing returns, and velocity has been maximized.

if comparing a 2" and 8" there will be a difference in velocity. but an 8" and a 10"? maybe not so much, depending on caliber, bullet weight, powder charge, etc.