The difference is that you're comparing a full-sized service gun to a compact CCW gun. If you want to compare a 9mm to a .357 Magnum snub, do so in comparable guns.
Please refer to my first post...
I made the comment that I placed the Hi Power right down on top of the model 66 - and guess what???
They were nearly the same exact size.
Nope - I''m making a 100% fair comparison there.
If two guns are the same size and weight, where's the difference?
A snub nose K frame is a pretty hefty piece.
The small grips tht S&W has can reduce the size a litte - but - not by a whole lot.
Please refer to my previous post. A K-Frame is one of the larger .357 snubs made. Most of the people looking at .357 Snubs these days are looking at small frame guns like a S&W J-Frame, Ruger SP101, Ruger LCR, or Taurus 605/650/651 all of which are smaller than a Browning Hi Power. You're cherry picking one of the larger .357 Snubs while ignoring the smaller and more common ones. If you want to look at full size autos, then let's consider the following: a Beretta 92 FS with a 4.9" barrel is 8.5" long while a S&W M67 (same size as a K-Frame Magnum) is 8.88" long. In comparing velocities of those sorts of guns, we find on BBTI's data that all the 125gr .357 Magnum loads broke 1400fps from the 4" revolver barrel but none of the 124-125gr 9mm loads could break 1300fps from the 4.9" Beretta's barrel.
Also, I think there's a pretty substantial difference between a 147gr bullet from a Browning Hi Power and a 158gr bullet going 100-150fps faster from a .357 snub, much less if you chronograph the 147gr 9mm from a small gun.
Excuse me - but - did you bother to read what I posted?
Who (but you) said anything about a 147 gr and/or a 158 gr.
I said 124 gr and 125 gr...
Now - let's look at the 124 gr from a Hi Power - a 124 gr +p clocks at ~ 1100 fps.
A 125 gr from a K frame - either model 19 or 66 - clocks at .....~ 1100 fps..
Those aren't my figures BTW - the late Steve Camp posted a wealth of information on both on his web site.
I brought it up because comparing only one bullet weight does not tell the whole story. Many people, myself included, prefer heavier bullets and in that respect the .357 Magnum has an even greater advantage.
Also, I don't know what data from the late Mr. Camp you're looking at, but here we see a Remington full-power 125gr .357 running 1243fps from a 2 1/2" M19
Here we have Federal and Remington full-power .357 loads running 1244fps and 1205fps respectively from a 3" GP100 and the Remington Golden Saber, which is not a full power loading, running 1189fps.
Here we have the mid-range Remington Golden Saber again running 1189fps this time from a 3 1/16" barrel Ruger SP101 (the 145gr Winchester Silvertip is running slightly faster with a heavier bullet because it is a full-power loading).
Here we have the mid-range Remington Golden Saber running 1141fps from a 2 1/2" M66 (and again the full-power Winchester Silvertip is both heavier and faster).
The data of Camp's that comes closest to supporting your comments is the 125gr Cor-Bon DPX averaging 1133fps from a 2 1/2" M19, but the DPX is not advertised as a full power load (advertised velocity is 1300fps from a 4" barrel) and Camp noted that this particular lot had trouble making advertised velocity even from a 4" barrel.
That's pretty bad news because a couple hundred fps is more than enough difference to be inside or outside a particular bullet's designed velocity window. In nearly every chronograph test I've ever seen or read, an extreme spread of 100fps or more is highly unusual
Then I strongly suggest you go to the site you're referring to - BBTI - and peruse the raw data.
A spread of 100 fps is very common.
Very first one - 115 gr Corbon - hi - 1445, low - 1274 - ES 171 that's from a S&W.
The Python w/a 6" barrel doesn't fare much better
`115 gr Cor Bon - hi -1356, low - 1193 - ES - 163.
Well - maybe that's just beacuse it's a 110 gr Cor Bon eh?
Let's move on down the list to something else....
How about a Federal 125 gr...
Hi - 1523, low, 1357 ES 163...
What's significant here is that two shots were in the 13's and two were in the 15's..
That's from the S&W
Python - hi - 1433, low - 1300 ES 133
You know what?
I'm really tired of this...feel free to look it up yourself...there's plenty more that are in the mid 100 fps range..
I already know what I know...
Guess what, the Colt Python and S&W 686 in the test were both running lots of high extreme spreads. I wouldn't be surprised to learn that those guns have cylinder gaps that are excessive or at least on the high side of normal.
Also, if you look at Camp's data where extreme spreads were provided, you'll find that there was only one case of an extreme spread over 100fps (ES of 114fps with the Remington full-power 125gr load from the 3" Ruger GP100).
An isolated incident of an extreme spread over 100fps is not really much cause for concern, but if I have a gun that's consistently giving extreme spreads well over 100fps with a variety of ammo or a loading that consistently giving extreme spreads well over 100fps from a variety of guns, then I'm going to start being concerned about something being wrong with the gun or ammo.
An extreme spread of 200fps is simply unacceptable as that's enough to be outside the velocity window of many loadings. For an example of this, look at the problems that were experienced when the .357 Sig was first introduced. Rather than develop caliber-specific bullets, the ammo manufacturers originally just took 124gr 9mm bullets (which were designed to be driven at 1150-1250fps) and ran them at 1400-1450fps. The result was that the bullets simply came apart and penetrated shallowly. By reducing the velocity of most .357 Sig loadings to the 1300-1350fps we see commonly today, they were able to bring the 9mm bullets back into, or at least closer to, their designed velocity window.
Likewise, a bullet moving too slow can give us problems too. Take for example, Winchester's 158gr LSWCHP .38 Special +P "FBI Load". Winchester advertises this loading at 890fps from a 4" barrel, so we can safely assume that it's designed to work at approximately that velocity.
In Stephen Camp's testing, it averages 807fps from five different S&W J-Frames, which is less that a 100fps velocity reduction.
However, Camp found that while it expands well from a 4" barrel, it barely expands at all from a 2" barrel when fired into water
(in ballistic gelatin, wetpack, or just about any other test media we could safely expect expansion to be even worse).
The point is that, depending on where your particular loading lies in your bullet's velocity window, an extreme spread of 200-300fps is easily enough to make the bullet overexpand, fragment, and/or penetrate shallowly or fail to expand. Because of this, an extreme spread of 200-300fps with a gun and ammo intended to be used for self-defense is, IMHO, completely unacceptable.