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Hi, I am new to handguns and still have lots to learn so I apologize for this poorly worded (and perhaps ignorant) question. I own a 4" python and shoot both .357 and 38 loads. A friend of mine said there is a lot of unburned powder left over from a .357 load because the barrel is too short and doesn't allow enough time. He said, consequently, you really aren't getting much more "power" (for lack of a better word) from the .357 loads than from the 38's. Can anyone shed a little light on this? And perhaps compare it to a 6" barrel?
 

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A longer barrel will give you more burn time and thus higher velocity, but a .357mag from a 4 inch barrel will have a dramatic increase of velocity over a .38sp even if it was fired from a 6 inch barrel.
The amount of unburned powder will depend on the buring rate of the powder. Slow buring powders will leave some of it unburnt, but faster burning powders will have been consumed in the barrel. The best way to notice this is to look for the flame when you fire a round. That flame is burning powder and a long flame means more powder buring.
To sum it all up, don't put a lot of faith in what your friend told you. While a .357mag is more efficient in a 6 inch barrel, it still has plenty of power from a 4 incher.
 

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I never was "into" ballistics, but if I'm not mistaken, a .357 Magnum from a 2 1/2" barrel generates more power than a .38 Special out of a 6" barrel.
 

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I am not an expert, but I am a student of internal Ballistics. In a nutshell, you hit peak pressure with most revolver loads in 38/357 at or before the bullet crosses the cylinder gap. Only with really slow powders and proper crimps can you get the peak pressure point much past the gap. So with a 38 special you hit peak pressure of around 18,000 lbs and with the 357mag you get around 35,000 lbs of pressure (don't quote me on the numbers I am doing this from memory but the mag is about 2x the special).

So, You may not have a long barrel to use all of that push, but lets be practical, 2x pressure will do a lot in a short distance.

Basically I agree with Dfaris. My experience with a chrono just about matches his comments.

Final thought, really fast powders in the special (bullseye, 231, titegroup etc) will be nearly consumed by the time the bullet leaves the cylinder, while in the magnum (2400, longshot, blue dot) will still be burning and as the pressure drops the combustion is less efficient and the powder does not burn well.

There is a very complicated powder burn profile for a revolver. It tends to peak and surge as the bullet first leaves the crimp, then hits the leade in the cylinder, then the cylinder gap, then the forceing cone in the barrel and finally engages the rifling.

It is really fascinating to try and understand why one powder works in a cartraige/gun and why the same powder does not work in another.

Good luck and hope this helps.

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Not to confuse the issue, but back in the 60's or early 70's Speer's reloading handbook, I believe, did an interesting article that has largely been ignored over the years since presumably the reality would really cut into the common BS in print about cartridges and stopping power and barrel length. Memory's a bit shy on the specific manual, I'll have to look that up.

In any event, they chronographed a variety of loads out of a selection of Colt, S&W, and perhaps Ruger revolvers in 357 and found that individual variations between fitting and polish of the various revolvers threw the lie to various generalizations about barrel length and velocity.

Different makes and even different models of the same piece shot with such variations in velocity that it virtually negated the traditional view about velocity and barrel length--at least in the 2.5 to 6 inch holster length guns.

Anyone else remember that article? Surely NOT picked up in the gunpress.

Another little nail in the coffin of the folks who arbitrarily discuss "stopping power" of various calibres and ctgs in quantifiable chartable terms--quite apart from ctgs that are in different stages of development of the projectile, differences in lots, and differences in the specific bullet path and vast differences in the target's reaction.

In general terms, though, a 357 will always allow more velocity and energy release than a 38 from the same barrel length....albeit with greater muzzle blast and recoil. The old saw oft repeated popular wisdom was that a 2.5 or 4 inch 357 was little better than a 6 inch 38. That begs the point on several levels.

Most folks, of course, DO shoot better with a bit more weight at the muzzle and with a greater sighting radius--except, of course, for some aging eyes that find the shorter barrels useful in recovering sights rapidly between shots.



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"And the blithe revolver began to sing/ To the blade that twanged on the locking-ring..."
 

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It's probably not the same article, and I don't remember what magazine it was in, but I remember a few years ago one took a gun, starting with a 7-1/2" bbl and sawed the barrel off in 1" chunks and then shot it and measured the results. It got to a point where there wasn't much change, but I don't remember what the length was. I'll have to check my stuff and see if I can find it.
 

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I couldn't find the article I was thinking of, but I did find one in the "Handgun Digest, 2nd edition", published in 1991, that has an extensive discussion of barrel length vs power.
 
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