Barrel length and accuracy

[Durango Dave]

How important is barrel length for accuracy?
It's a question that appears to have an obvious answer. Everyone knows a gun with a long barrel length has more accuracy. Rifles are more accurate than pistols because they have longer barrels. Much of that is because of sight radius. When the front sight is much farther ahead of the rear site it's easier to aim with accuracy. Besides that, how important is the barrel length? I would think this should be easy to verify. If a snub nose revolver were mounted securely in a vice-like mount, pointing to a target but still sprayed in a wide pattern, it's obvious that no marksman could make that gun perform.
Especially with revolvers, you can buy guns that are identical except for the barrel length. Are there any tests that compare accuracy vs. barrel length?

If I were to buy a revolver with a 8 inch barrel can I expect better accuracy than if it had a 5 inch barrel?

A long pistol can be cumbersome.

 

[GunnyGene]

How important is barrel length for accuracy?
It's a question that appears to have an obvious answer. Everyone knows a gun with a long barrel length has more accuracy. Rifles are more accurate than pistols because they have longer barrels. Much of that is because of sight radius. When the front sight is much farther ahead of the rear site it's easier to aim with accuracy. Besides that, how important is the barrel length? I would think this should be easy to verify. If a snub nose revolver were mounted securely in a vice-like mount, pointing to a target but still sprayed in a wide pattern, it's obvious that no marksman could make that gun perform.
Especially with revolvers, you can buy guns that are identical except for the barrel length. Are there any tests that compare accuracy vs. barrel length?

You have to specify accuracy & precision at a specific distance. This is partly due to bullet velocity ( a function of barrel length among other things), imparted spin, and resulting trajectory. In addition to that, a projectile that leaves the barrel at over mach 1 will decelerate in flight and pass thru a turbulent phase as it enters the trans sonic region, which usually has a significant impact on the trajectory and hence the point of impact. Thus a subsonic bullet is often more accurate & precise at a short range than a slightly supersonic bullet that transitions to subsonic before it reaches the same target.

It's all far more complicated than merely barrel length. For example, the barrel crown is important. If it's not absolutely concentric to the barrel you'll have problems no matter the length.

To answer your last question: Maybe.

 

[cas6969]

Everyone knows a gun with a long barrel length has more accuracy.

Incorrect.

Rifles are more accurate than pistols because they have longer barrels.

Also incorrect. :wink:


Speaking in more general terms, shorter barrels are more ridged and often more accurate than longer ones.
Dedicated "techinical pistol" shooters (bolt action/break action single shots) often put most rifles/rifle shooters to shame. But it's not because the barrels are long or short. :lol:

 

[WIL TERRY]

BBL length had NOTHING to do with inherent accuracy in rifles or handguns. This is easily provable and has been done MANY times.
And so it goes...

 

[Rumrunner]

I guess you never saw Bob Munden shoot his snub nose revolver at 100 yards.

As noted by cas, the stiffer the barrels the more accurate they USUALLY are. Thus some handgun barrels are more accurate than many rifle barrels of the same taper. You are correct that longer barrels have a longer sight radius thus making them easier to shoot accurately. Of course i using optics, this is a mute point.

Longer barreled pistols can be more cumbersome than a shorter one. Everything is a compromise. I prefer 4" and 5" barrels when it comes to revolvers. I have 8",12", & 14" barrels for my Encore.

 

[Snake45]

I know that THEORETICALLY, barrel length has little or nothing to do with accuracy.

HOWEVER...

I can tell you that I have a number of identical revolvers in both 4" and 6" lengths (and a couple even shorter than that).

Over the years, I've done a number of short vs long shootoffs. In every case but one (and that one was with just one type of ammo), the longer barrel was more accurate.

Now I know there will be those who will want to argue with me, but it is what it is. :wink:

 

[GunnyGene]

I guess you never saw Bob Munden shoot his snub nose revolver at 100 yards.

As noted by cas, the stiffer the barrels the more accurate they USUALLY are. Thus some handgun barrels are more accurate than many rifle barrels of the same taper. You are correct that longer barrels have a longer sight radius thus making them easier to shoot accurately. Of course i using optics, this is a mute point.

Longer barreled pistols can be more cumbersome than a shorter one. Everything is a compromise. I prefer 4" and 5" barrels when it comes to revolvers. I have 8",12", & 14" barrels for my Encore.

Y'all, I think we ought to give the new guy some time to catch up with us in regards to internal, external and terminal ballistics before beating him up too much. :lol: :wink:

 

[Rclark]

, the longer barrel was more accurate.

Only because (in most cases), one can shoot longer sight radius revolvers better. I know I do. I compromise on 5 1/2" because it is easy to carry and the distances I shoot, it is more than accurate enough. If I was handgun hunting though, I'd prefer the 7 1/2" revolver.

 

[DPris]

Your assumptions & "everybody knows" are not supported by fact, DD.
Denis

 

[Rumrunner]

Wow, wasn't beating him up just offering some observations.

As far as the difference in a 5" or 8" revolver try to handle both and if possible shoot both. I find that if a gun just feels better in my hands I tend to shoot it better. That is why I prefer shorter barrels on my revolvers. Also what would your main use be? For hunting you may want or depending on state regs need the longer barrel.

 

[mikem2]

Combination of physics, engineering, and variables.
All involved in shooting sports.

Add shotgun barrel length as associated topic in accuracy/pattern for target or hunting applications. Is 26" the optimal length for pattern, results, and balance/speed of movement? Plus the variable of gauge. Trap shooters 30" or sometimes 32" and sporting clays 26" or 28". Add the variables, of choke size and ammunition.....

 

[GunnyGene]

Wow, wasn't beating him up just offering some observations.

Sorry if it sounded like I was picking on you. That wasn't my intention.

 

[MaxP]

BBL length had NOTHING to do with inherent accuracy in rifles or handguns. This is easily provable and has been done MANY times.
And so it goes...

This....

Now it is true that the longer sight radius is helpful to many shooters, however, barrel length does not determine inherent accuracy.

 

[REP1954]

What MaxP said although types of sights do come into play also.

 

[powder smoke]

Everything has something to do with accuracy cylinder to forcing cone alignment
cylinder gap crown and especially technique. Accurate firearms are a joy if you
do your part. IMO that is the largest factor with Modern firearms. ps

 

[GunnyGene]

Everything has something to do with accuracy cylinder to forcing cone alignment
cylinder gap crown and especially technique. Accurate firearms are a joy if you
do your part. IMO that is the largest factor with Modern firearms. ps

I know people tend to use the word "accuracy" as sort of a catch all, but since I'm a little anal about such things, I really wish that at least those of us who know the difference between accuracy and precision, how they interact, and how to cope with both would use the proper terms if for no other reason than to avoid confusion of new shooters.

Not picking on you, everyone is guilty of doing this.

 

[Chuck 100 yd]

Everything has something to do with accuracy cylinder to forcing cone alignment
cylinder gap crown and especially technique. Accurate firearms are a joy if you
do your part. IMO that is the largest factor with Modern firearms. ps

I know people tend to use the word "accuracy" as sort of a catch all, but since I'm a little anal about such things, I really wish that at least those of us who know the difference between accuracy and precision, how they interact, and how to cope with both would use the proper terms if for no other reason than to avoid confusion of new shooters.

Not picking on you, everyone is guilty of doing this.

Please explain the difference between precision shooting and accurate shooting.

 

[Heliman]

My personal experience is that the difference between a 4" and 6" is negligible when we are talking 25-30 yds. I personally shoot mainly 4" revolvers with the exception of a 5" 629. Used to own 7 1/2" Supers, but got to the point I couldn't see the front sight very well. I found the 4" better for sight visibility hence better accuracy. Just my experience.

Dave

 

[GunnyGene]

Everything has something to do with accuracy cylinder to forcing cone alignment
cylinder gap crown and especially technique. Accurate firearms are a joy if you
do your part. IMO that is the largest factor with Modern firearms. ps

I know people tend to use the word "accuracy" as sort of a catch all, but since I'm a little anal about such things, I really wish that at least those of us who know the difference between accuracy and precision, how they interact, and how to cope with both would use the proper terms if for no other reason than to avoid confusion of new shooters.

Not picking on you, everyone is guilty of doing this.

Please explain the difference between precision shooting and accurate shooting.

Seriously? You don't know? Ok. Briefly and without getting into the math:

Precision in terms of shooting (or any ballistics) is a measure of the group size somewhere on the target and is independent of POA. Given the same POA for multiple shots the group will cluster in a roughly circular area, which may or may not be the desired POI. It is a statistical description known as Circular Error Probable (CEP) where some desired percentage of the shots fall within a specified area - say 50% of the shots fired will be within a circle of radius 3" measured from the approx center of the group. Perfect precision (perfect group) would be all shots going thru the same hole. Accuracy is when POI is equal to POA with the same grouping/precision as you established initially, and is easily accomplished simply by adjusting your windage and elevation as necessary to move the POI, and account for external variables.

Which is why I and any decent shooter will spend a great deal of time on their position, trigger control, breathing, etc. , and the equipment (firearm, optics, ammo) to obtain the tightest group he and the equipment are capable of (or comfortable with), before making any adjustments to bring POI into agreement with POA. This sequence, Precision followed by Accuracy, is important when sighting in a new weapon, or after any changes in ammo or weapon system.

 

[Snake45]

I found the 4" better for sight visibility hence better accuracy. Just my experience.

Dave

And you're not alone. Some people get a better, sharper sight picture with a shorter sight radius.

 

[CraigC]

As stated, barrel length has no bearing on raw accuracy potential. Which is exclusive of shooter related factors like balance, sight radius and weight.

 

[Durango Dave]

BBL length had NOTHING to do with inherent accuracy in rifles or handguns. This is easily provable and has been done MANY times.
And so it goes...

Everything has something to do with accuracy cylinder to forcing cone alignment
cylinder gap crown and especially technique. Accurate firearms are a joy if you
do your part. IMO that is the largest factor with Modern firearms. ps

Okay, I'm a newbie. I am hoping to learn something. What I've learned so far is several people say I am wrong. I hope to learn some specifics.
I realize it is very possible for a short gun to be shot with more accuracy than a long gun. Let me emphasize again, what if all factors were the same except the barrel length. Such as 2 revolvers with the same "accuracy cylinder to forcing cone alignment cylinder gap crown and especially technique". (I didn't even know what that mumbo jumbo meant until I started googling) The same everything except different barrel length. Both barrels strait.
Wouldn't a long barrel Blackhawk be more accurate than a short barrel Blackhawk if everything else was the same.

 

[Snake45]

BBL length had NOTHING to do with inherent accuracy in rifles or handguns. This is easily provable and has been done MANY times.
And so it goes...

Everything has something to do with accuracy cylinder to forcing cone alignment
cylinder gap crown and especially technique. Accurate firearms are a joy if you
do your part. IMO that is the largest factor with Modern firearms. ps

Okay, I'm a newbie. I am hoping to learn something. What I've learned so far is several people say I am wrong. I hope to learn some specifics.
I realize it is very possible for a short gun to be shot with more accuracy than a long gun. Let me emphasize again, what if all factors were the same except the barrel length. Such as 2 revolvers with the same "accuracy cylinder to forcing cone alignment cylinder gap crown and especially technique". (I didn't even know what that mumbo jumbo meant until I started googling) The same everything except different barrel length. Both barrels strait.
Wouldn't a long barrel Blackhawk be more accurate than a short barrel Blackhawk if everything else was the same.

The thing is, everything else will NEVER be "the same" between two guns. Even two with the same barrel length.

Only way this could be settled would be to start with say a dozen different long-barreled revolvers, shoot them in a machine rest, cut the barrels and inch and recrown, shoot again, cut another inch, etc etc etc. After you've done THAT you might be able to make some kind of definitive statement about barrel length vs "accuracy." :wink:

Fact is, not one shooter in ten can tell the "accuracy" difference from actual field shooting positions (i.e., not a benchrest). Maybe not one in a hundred.

 

[DPris]

Essentially, the answer is still: Barrel length does not determine superior or inferior accuracy in a handgun.
Denis

 

[Biggfoot44]

Unless you go to redicously short like less than bullet length, or so long the bullet sticks and doesn't exit , bbl length per se makes no.difference .

In a revolver there are a whole buncha factors - headspace, chamber specs, chamber consistancy, throat dimentions and quality, throat consistency, cylinder concentracy to bore, bbl cylinder gap, consistency of gap, forcing cone design, smothness, and squareness, bore sizing, bore consistency, design and quality of rifling, quality of crown . Probably some more not thinking of at the moment .

Factor that effect how well their potential can be used in human hands include - fit in the hand, subjective trigger pull quality, subjective balance, and sight radius * if using iron sights * .

Out of all the above, sight radius is definitely effected by bbl length, subjective balance is subjective, could go either way .

The practical effect of objectively shorter sight radius varies depending upon the shooters visual acquity, depth of focus, and ability to rapidly shift focus . Some sets of eyeballs can take advantage of longer spacing . Some sets of eyeballs can't rapidly switch focous as well , and obtain clearer sight picture with shorter.

In * my * anecdotal experience , there is a certian accuracy baseline that reflects my trigger pulling, and sight aligning skills from a two hand braced position . Call it X inches at 25yds . Up to X plus 25% is admirably accurate gun and load. The occasional less than X is probably statistical randomness.

I've shot groups that match my baseline capability ( X at 25yds) with guns of 2- 7.5 inches .

 

[Jimbo357mag]

My personal experience is that I can shoot my 6" and 7.5" barrel revolvers more accurately than my 3" and 4" revolvers for whatever reason. I am sure that 'practically' most shooters could shoot a 6" barreled gun more accurately than a shorter or longer one. Short barrel guns have problems with sight radius and extra long barrels have problems with balance and weight.

The gun I shoot best is a S&W 38 special with a 6" barrel.

BTW - Most revolver shooters are very opinionated and vary greatly in their preferences.

 

[choirboy]

If the bullet is stabilized by the barrel it won't care how long that barrel is. I think we sometimes confuse the intrinsic accuracy of the firearm with practical accuracy (where the shooter is involved)

 

[CraigC]

Only way this could be settled would be to start with say a dozen different long-barreled revolvers, shoot them in a machine rest, cut the barrels and inch and recrown, shoot again, cut another inch, etc etc etc. After you've done THAT you might be able to make some kind of definitive statement about barrel length vs "accuracy." :wink:

Fact is, not one shooter in ten can tell the "accuracy" difference from actual field shooting positions (i.e., not a benchrest). Maybe not one in a hundred.

It's been done, many times.

 

[Snake45]

Only way this could be settled would be to start with say a dozen different long-barreled revolvers, shoot them in a machine rest, cut the barrels and inch and recrown, shoot again, cut another inch, etc etc etc. After you've done THAT you might be able to make some kind of definitive statement about barrel length vs "accuracy." :wink:

Fact is, not one shooter in ten can tell the "accuracy" difference from actual field shooting positions (i.e., not a benchrest). Maybe not one in a hundred.

It's been done, many times.

I've seen it done "many times" to measure velocity, but don't think I've ever seen it done for "accuracy" tests.

 

[GunnyGene]

Only way this could be settled would be to start with say a dozen different long-barreled revolvers, shoot them in a machine rest, cut the barrels and inch and recrown, shoot again, cut another inch, etc etc etc. After you've done THAT you might be able to make some kind of definitive statement about barrel length vs "accuracy." :wink:

Fact is, not one shooter in ten can tell the "accuracy" difference from actual field shooting positions (i.e., not a benchrest). Maybe not one in a hundred.

It's been done, many times.

I've seen it done "many times" to measure velocity, but don't think I've ever seen it done for "accuracy" tests.

There is one condition in which a longer barrel can be less accurate than a substantially shorter barrel using the same ammo.

If the short barrel mv is subsonic, but a long barrel boosts the velocity of the bullet above the transonic region at the muzzle, it's likely the bullet fired from the long barrel will destabilize as it slows in flight to under 1200fps resulting in unpredictable departures from the expected trajectory. Because of this, the "effective range" of a firearm is given at the point in the trajectory where the bullet enters this transonic region. Design of the bullet itself also plays a significant part in whether it will destabilize significantly or not.

Here's a short article that discusses dynamic stability that applies to this:

https://loadoutroom.com/thearmsguide/long-range-shooting-external-ballistics-dynamic-stability/

PS: The transonic region extends from approx 1300fps to 870fps with Mach 1 being approx. 1087fps , all depending to some extent on atmospheric conditions.