Long vs. short barrel

[superstring]

There have been a few discussions recently about "standard" vs. "compact" pistols. It got me wondering if, besides balance and sight radius, there are other advantages in a short barrel over a long barrel or vice versa?

Someone once told me that a longer barrel results in a higher projectile (bullet/pellet) exit velocity. I'm not sure if that's true, but what about the extra barrel friction?

[Rover]

Unlike firearms where the powder continues to burn as the bullet moves down the barrel, an AP releases its "charge" instantaneously.

Therefore, a shorter barreled AP will have a higher velocity than a long one due to friction. A longer barreled firearm will have a higher velocity than a short one due to continued pressure.

In International pistol the barrel length is regulated, so the point may become moot.

[superstring]

Thanks, Rover. That makes sense. Then, with AP, it really does come down to balance and sight radius.

[FredB]

Actually, what Rover said is always correct only for spring-piston guns. It may not be correct for CO2 and CA guns, depending on how the velocity is adjusted. Particularly for CO2 guns, a longer barrel may well give the CO2 a chance to expand more, increasing velocity, especially if there is any liquid CO2 in the amount metered out by the valve.

HTH,
FredB

[David Levene]

Then, with AP, it really does come down to balance and sight radius.

That doesn't always follow. With the Morini 162 range for example, the sight radius for full length and compact versions is 310-360mm. The compact uses an extended rear sight carrier to achieve this.

[frog5215]

Unlike firearms where the powder continues to burn as the bullet moves down the barrel, an AP releases its "charge" instantaneously.

Therefore, a shorter barreled AP will have a higher velocity than a long one due to friction. A longer barreled firearm will have a higher velocity than a short one due to continued pressure.

In International pistol the barrel length is regulated, so the point may become moot.

This is wrong, wrong, wrong, except, perhaps for springers.

PCP and CO2 both tend to benefit (with regard to velocity) from longer barrels.Steyr, Walther, Anschutz, and Walther were having a little difficulty getting a reasonably number of shots per charge with their early field target guns until they lengthened their barrels. Velocity increases all the way down the bore (at practical barrel lengths).

The issue with AP is whether the increased barrel time is a problem. I think for most shooters, balance and sight radius are more important factors.

[David M]

Both the long and short barrel PCP pistols usually shoot a pellet at the same set velocity, usually about 150mps (adjusted by a setting screw and checking the speed on a chronograph).
The only difference will be the amount of gas to be used, but then they usually have different size tanks.
The biggest difference is the weight and balance in your hand.

[frog5215]

Good point, I forgot the adjustment of modern guns.

[peterz]

I've been looking into another aspect of the question, and have corresponded with Steyr. It seems that the largest part of the weight difference is in the air cylinder. There is a weight difference of 68 gm for the LP-10/LP-10 Compact pair. Of that 68 grams 50 are in the air cylinder alone, leaving only 18 gm for the barrel and shroud weight difference.

So putting a compact tank on the LP-10 gets you most of the advantages of the smaller pistol. The center of mass is moved back almost as far as it would be going from standard to compact; the shortest sight line of the LP-10 is one millimeter longer than the longest sight line of the Compact (If you are trying to reduce the sight line, this is clearly not the way to go!). But if it is weight and balance, and if you already have an LP-10, it is an easy way to get most of the advantages without buying a new pistol.

Finally, in one of the brochures available on the Steyr site, it says that a Compact pistol can be converted to a full-sized one by exchanging barrel and shroud. If the long barrel and shroud can be bought separately, I suppose that the short ones can be too. So it does seem possible to convert an LP-10 for what might be a reasonable price.

[Shooting Kiwi]

All other things being equal, surely a shorter barrel is preferable because of the shorter barrel time.

The 'nose-heaviness' of a long-tank air pistol is considerably greater than that of a 'short-tank' version. Both are considerably more 'nose-heavy' than any standard pistol I've handled. Given this, and the acute grip angle, there is much more wrist effort required to hold up the muzzle of an air pistol, compared to a standard pistol. Why design them like this? Muzzle weights are generally applied to standard pistols to get them back on aim quickly after recoil, rather than to steady the hold (I believe), and this is obviously not a requirement for a slow-fire, non-recoiling air pistol. I'm not exactly a weakling, but I find that I have a much steadier hold with my standard pistols than my FWB P44. Can someone please explain?

[frog5215]

The comparison isn't with a Standard Pistol, but with a Free Pistol.

[superstring]

All other things being equal, surely a shorter barrel is preferable because of the shorter barrel time.

The 'nose-heaviness' of a long-tank air pistol is considerably greater than that of a 'short-tank' version. Both are considerably more 'nose-heavy' than any standard pistol I've handled. Given this, and the acute grip angle, there is much more wrist effort required to hold up the muzzle of an air pistol, compared to a standard pistol. Why design them like this? Muzzle weights are generally applied to standard pistols to get them back on aim quickly after recoil, rather than to steady the hold (I believe), and this is obviously not a requirement for a slow-fire, non-recoiling air pistol. I'm not exactly a weakling, but I find that I have a much steadier hold with my standard pistols than my FWB P44. Can someone please explain?

This seems like a very good question. Are there any top class shooters using a "compact" AP? If not, why not, if it's just a personal preference (balance) thing?

The comparison isn't with a Standard Pistol, but with a Free Pistol.

Not sure I understand this statement, frog??

[FredB]

All other things being equal, surely a shorter barrel is preferable because of the shorter barrel time.

The 'nose-heaviness' of a long-tank air pistol is considerably greater than that of a 'short-tank' version. Both are considerably more 'nose-heavy' than any standard pistol I've handled. Given this, and the acute grip angle, there is much more wrist effort required to hold up the muzzle of an air pistol, compared to a standard pistol. Why design them like this? Muzzle weights are generally applied to standard pistols to get them back on aim quickly after recoil, rather than to steady the hold (I believe), and this is obviously not a requirement for a slow-fire, non-recoiling air pistol. I'm not exactly a weakling, but I find that I have a much steadier hold with my standard pistols than my FWB P44. Can someone please explain?

The inch or two difference in barrel length we are talking about would only theoretically make any difference if, somehow, you kept the gun absolutely still until you fired it, and then started to move it. Since in reality the gun is moving all the time, whatever extra tiny fraction of second the projectile remains in the longer barrel could just as easily help you as harm you. That's assuming, of course, that you haven't given the trigger a violent jerk, in which case maybe the longer barrel might make a 2 into a 1 - or not, depending on the direction of movement.

Your hold appears much steadier with your standard pistol than with your P44 because the P44 has a much longer sight radius. There's probably little, if any, real angular difference.

HTH,
FredB

[frog5215]

Super, my impression of Standard pistols is that on average, the grip angle tends to be more 1911 like than free/air pistols, which is where most of my limited experience lies. I don't shoot SP.

On average, I feel like APs and FPs have that droopy broken wrist thing going on, along with the set trigger on FP. So I find the AP and FP similar and any SP I've handled quite different. Thus I find SP analogies to AP somewhat specious.

[superstring]

Gotcha, frog5215. I also like the word "specious" Excellent! :-)

[Shooting Kiwi]

Your hold appears much steadier with your standard pistol than with your P44 because the P44 has a much longer sight radius. There's probably little, if any, real angular difference.

FredB, I wish that were the case, but it isn't. I find the AP nose-heaviness allows a pendulum-like slow horizontal swing to develop and the hold is definitely worse than with my SPs: the angular displacements really are worse. OK, it might be my lousy technique, but the phenomenon is real.

I agree that the effects of the slight barrel shortening are almost neither here nor there. I wish my trigger releases never deflected the aim, however.

Thus I find SP analogies to AP somewhat specious.

frog5215, whether you consider that specious is up to you, but I was making a contrast, not drawing an analogy.

I agree that AP and FP can be considered closer relatives than AP and SP. Even so, my P44 feels more nose-heavy than my TOZ 35. One day I'll get around to measuring moments.

Perhaps I should try again. We agree APs are nose-heavy, perhaps the most nose-heavy of any of the competition pistols. Why make them like that, and then compound the problem of the effort required to hold the muzzle up by making the wrist adopt a semi-drooped position, which is anatomically not particularly suited to the task? Alternatively, why not make SPs much more nose-heavy?

[TomAmlie]

Perhaps I should try again. We agree APs are nose-heavy, perhaps the most nose-heavy of any of the competition pistols. Why make them like that, and then compound the problem of the effort required to hold the muzzle up by making the wrist adopt a semi-drooped position, which is anatomically not particularly suited to the task?

Perhaps this was the reasoning behind some of the lod AP designs that had the vertical air/CO2 resevoir directly in front of the trigger guard....get less weight way out there in front, and get the center of gravity back closer to the hand?

[Makris D. G.]

I find that drooped wrist offers much more stability and is less tiring than a vertical grip. I shoot mostly AP and FP, and when I get to shoot SP with a Walther GSP it is much more tiring for my wrist and harder to keep the muzzle up.

[Luftskytter-]

Two things going on here:

Grip angle/droop: I've recently adjusted the grip of my MG1E because I felt the extreme "droop" disturbed pulling the trigger and made my hand/arm too passive. But then I've got plenty of strength to handle this. My son who's a very good "normal pistol" shooter looks at these anatomic things with scorn. Sometimes I think he's onto something. With a strong natural grip it's easy to "lock" your hand in a position that just happens to make a 1911 point straight ahead. And a strong grip also means you can handle some extra mass.

Forward heavy:
why did they use weights on the vertical cylinder APs to move the weight forward? Target archers do the same thing. I also feel that my old backheavy FWB65 is to easy to wave around. It doesn't tolerate any twitching whatsoever. So I believe we need some Moment of Inertia to counteract those unwanted rotational movements. That means mass far away from the centre of rotation, i.e. forward, since otherwise it wouldn't fit in the box.

Then of course it's a matter of degree:
the mass that prevents my occasional twitchy shot from becoming a seven may help a better shooter avoid shooting an eight or a nine.

And shooting the ol' 65 is good excercise to learn avoiding those little mistakes: it's not forgiving at all!

[FredB]

Perhaps I should try again. We agree APs are nose-heavy, perhaps the most nose-heavy of any of the competition pistols. Why make them like that, and then compound the problem of the effort required to hold the muzzle up by making the wrist adopt a semi-drooped position, which is anatomically not particularly suited to the task? Alternatively, why not make SPs much more nose-heavy?

There is a huge amount of latitude available in designing these pistols, in terms of grip angle and weight distribution. You are asking why they are designed the way they are. That's the same as asking: "Why doesn't everybody else have my preferences?" They just don't. The problems you mention are problems for you, not the majority.

You don't like your P44's balance? Find an AP that's muzzle-light, such as the alu-barreled Hammerli. Adjust the grip angle to your liking - that's why all these choices are available. If there are fewer choices available to suit your preferences, that just means that the majority have other preferences.

And BTW, I don't agree that "APs are nose-heavy, perhaps the most nose-heavy of any of the competition pistols." Many free, standard and especially rapid fire pistols, mostly the magazine-forward designs, are just as nose-heavy or more so. Again, that's the user's choice.

HTH,
FredB