For the sake of example, let's take the M&P 1.0, which comes in a 3.5", a 4.24" or a 5" barrel. Or, if you prefer, take the Colt Python, which were at one point or another was offered in 2.5", 3", 4", 6", and 8" barrels.

Obviously sight radius can contribute to a shooter's accuracy. So that right there gives a longer barrel gun an accuracy advantage, unless you are using some type of modern optics/sights in which case site radius matters not.

Also, obviously a longer barrel (within limits) offers more velocity in feet/second, and therefore more power, and I can see how higher velocity might contribute to more accuracy, although I'm not certain on this point. Do faster bullets from a longer barrel make it to the center of the target easier than the same bullet fired slower from a shorter barrel simply because of the increased speed?

Finally, the longer barrel guns handle differently, in particular in a revolver since more weight is in the front, and I can see how more weight could be helpful in helping a shooter be more accurate, at least within limits.

But are there other advantages to a longer barrel?

Maybe the longer barrel might have more time to spin the bullet contributing to some accuracy??????? Maybe something about bullet stabilization??? These details are a little fuzzy for me. There are different "twist rates" in barrels, but I never stopped to think if a bullet spinning faster would be more accurate. And would a long barrel and short barrel with the same twist rate result in the bullet spinning at the same rate?

So, my physics is a bit rusty.

Other than the sight radius and increased velocity (power), what are the advantages of a longer barrel on a handgun?

thanks much.

Back in the days when the only “legitimate” reason to own and shoot a handgun was bull’s eye competition, it was common for the cartridges used to be loaded with powderpuff loads. The same is still true of some disciplines. They did not suffer from lack of accuracy (or “precision” as some prefer to call it today) to any practical degree, or at least not to any measurable extent. What they offered were lower recoil that was easier on the shooter and disturbed the aim less, making for faster follow-up shots (if required).

The primary reason for longer barrels was, as you identified yourself, to increase the sight radius and therefore greater practical accuracy due to the lessened effects of any sight misalignment. Some guns intended for the purpose had front sights that could be extended out ahead of the muzzle to increase the sight radius even farther. The other reason for longer barrels was to add weight, and thereby increase the inertia of the gun and help increase its stability as it was being held by nothing more than the shooter’s muscles. Both reasons are/were why rifles such as those used for “small bore” (.22 rimfire) shooting have/had long, heavy barrels. My Winchester model 52 doesn’t have its massive barrel to control recoil or to increase velocity; in fact, bullet velocities would probably be higher if its barrel were shorter.

Higher bullet velocities might offer some slight advantage in that the bullet leaves the barrel more quickly, but if that were important enough, target shooters would fire powerful loads from short barrels. They don’t.

As the ballistician Bryan Litz* explains in his series of books on the subject, a higher rate of bullet spin does not increase accuracy (he is one who calls it precision)—just the opposite in fact. The exception is that the bullet must be spun fast enough to stabilize it, and that can become vital at long distances—but long range stability is not something that would be of concern for a handgun intended for short range target shooting. The reason is that a faster rate of spin increases the effect of any irregularity in the bullet’s construction, and he points out that the benchrest shooters whose only goal is maximum precision usually spin their bullets as slowly as they can get away with.

* For anyone interested in the subject, I highly recommend Litz’s books, starting with Modern Advancements in Long Range Shooting, Volume I. A long review of the series is still available here.

Advantages are longer sight radius, less muzzle rise (better split times) and more velocity. Having said that, last year I shot my best IDPA classifier with a 320 compact. I did better than I ever did with my 320 full size. So slide length is maybe not a big deal.

quote:

Originally posted by 10round:
So slide length is maybe not a big deal.

Depends because shooting conditions and disciplines vary. Sometimes it helps to have a longer sight radius, sometimes it doesn’t.
What is not in question, though, is that a longer sight radius reduces the effects of sighting errors. Sometimes that potential benefit matters, sometimes it doesn’t.

I think that accuracy is helped by longer barrels- sort of. Higher velocity (from the longer push out of a longer bbl) means a flatter trajectory to target, and thus lessens the need for a modified sight picture- i.e. "holdover".

Strictly speaking, the longer barrel doesn't actually shrink group size (except for the benefit of a longer sight radius). But error from imprecise holdover just tends to get lumped in with the whole accuracy issue. Really, only the POI has changed, not group size, but for many people, a miss is still a miss.

(There's a slightly different answer when we start discussing long guns. Once you get into typical rifle barrel lengths, vibrational characteristics raises its ugly head. Contrary to popular belief, a barrel that is excessively long can be detrimental to accuracy due to increased harmonics. A shorter, stiffer barrel is actually better for accuracy, except now you start to limit practical range, again due to bullet drop.)

[tigerbloodwinning covered some of these points as I was typing.)

Other things to consider would be cycling inertia and recoil tension.

The longer slide would theoretically have more weight and not need as heavy of a spring to manage recoil.

Sight Radius is IMO a bit overblow. I have a 2 1/2 S&W model 19 and one day at a local range that offers an indoor 50 yard rifle range I decided to test myself with the model 19 at 50 yards. Shooting in single action I found that I was able to keep 12 rounds within an 11 inch circle. That surprised me a bit because with a with my 6 inch Dan Wesson I really concentrate to achieve the same level of accuracy. After a bit of head scratching I determined that short barrel brought the front sight closer to the rear sight notch and one result of this was a very tight fill between the front post and the rear notch on the revolver. Thus I was able to maintain a higher level of sighting consistency.

Another factor in play is that in Mechanical Terms a shorter barrel is "stiffer" and that also can effect accuracy. However I suspect that difference is so minor that it really is not measurable.

So, what it comes down to when shooting any handgun offhand it is critical to accuracy is how well the shooter can repeat an identical sight picture for each shot. For something like Bullseye a very tight "fill" between front and rear sights makes it much easier to maintain a consistent sight picture.

quote:

Originally posted by Scooter123:
So, what it comes down to when shooting any handgun offhand it is critical to accuracy is how well the shooter can repeat an identical sight picture for each shot.

Yes, that is critical, and it varies among shooters. Some like a tight image between front and rear sights, some don’t. The experienced shooter and prolific writer of my youth, Skeeter Skelton, preferred a narrower front sight for the precision that gave him. He wrote that he ordered S&W revolvers like the model 19 with front sights 1/10 inch wide rather than the usual 1/8".
The enclosed globe front sight I used during my small bore shooting days came with multiple inserts for the same reason. I liked a circle that left only a small white ring around the bull’s-eye at 50 feet, but other shooters (with poorer visual acuity?) liked more space, and some even preferred a traditional post.

Despite different personal sight design preferences, though, if both sights are misaligned to the same degree, a shorter sight radius will produce a greater POI error than a longer sight radius. That’s just basic mathematics.