Bullet velocity in small barrels
- Thread starter Maromero
- Start date
Your question begs the question of "Do .40 S&W bullets usually keep their velocity in short barrel guns?"
The answer is no.
http://www.ballisticsbytheinch.com/results.html
This shows that .40 S&W bullets lose velocity as the barrel length is shortened.
The answer is no.
http://www.ballisticsbytheinch.com/results.html
This shows that .40 S&W bullets lose velocity as the barrel length is shortened.
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The question was made in comparison to other cartridges. Using data from www.ballisticsbytheinch.com and comparing velocities of both 5 & 2 inch results, a .45 sheds 15 to 18% velocity, the .44 sheds 26-30%, .40 14-15%, .357 34-39% and 9mm @17%.
I believe this info is critical when selecting a cc weapon. Settling on a 3 inch barrel a .45 230gr. is going @787 and a 185+P @967, a .40 180gr. 962, a .357 158gr. @1122 and a 125gr. 1255, and a 9mm 115+P @1134 and a 124+P 1061.
I'm not here to argue shot placement is the most important thing along with other important factors but comparing calibers in a 3 inch barrel the .40 looks better than the others, imho.
I believe this info is critical when selecting a cc weapon. Settling on a 3 inch barrel a .45 230gr. is going @787 and a 185+P @967, a .40 180gr. 962, a .357 158gr. @1122 and a 125gr. 1255, and a 9mm 115+P @1134 and a 124+P 1061.
I'm not here to argue shot placement is the most important thing along with other important factors but comparing calibers in a 3 inch barrel the .40 looks better than the others, imho.
Brian Pfleuger
Moderator Emeritus
Percentages don't really tell much. What are the true differences in real numbers? The 9mm actually loses LESS fps (at least in some cases), even though it's a higher percentage....
For instance, 135gr Hydro-shoks.... 40SW loses 261fps from 5" to 2" and 9mm loses 176fps.... that doesn't seem like an advantage for the 40 to me.
As a matter of fact, the 40 loses 37.8% (449ft/lb down to 278) of it's energy while the 9mm loses only 29.8% (352ft/lbs down to 247).... seems like an advantage to the 9mm in both fps and energy....
For instance, 135gr Hydro-shoks.... 40SW loses 261fps from 5" to 2" and 9mm loses 176fps.... that doesn't seem like an advantage for the 40 to me.
As a matter of fact, the 40 loses 37.8% (449ft/lb down to 278) of it's energy while the 9mm loses only 29.8% (352ft/lbs down to 247).... seems like an advantage to the 9mm in both fps and energy....
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I don't know. A .45 185+P @ 950 carries a kick and the 180gr .40 is going out at a faster velocity with probably a less unpleasant recoil while a 230gr. is well below 800ft/sec. A 9mm +P is traveling at the speed of a regular 9mm and the .357 looses a lot of speed with a very stiff recoil.
Maybe the .40 S&W has a place after all!
Brian Pfleuger
Moderator Emeritus
Maromero said:
See my post above....
The difference between the 40 and 9mm with that particular round in a 2 inch barrel is 31ft/lbs. 31 foot pounds is roughly the energy produced by a VERY weak bow and arrow. It is a completely irrelevant number in the world of firearms. As a matter of fact, I would guess that in any given pair of guns the two could easily be equal.
@peetzakilla:
Do you believe that a 9mm Corbon 125gr.+P at 1108 ft./sec (non +P velocities) and a .40 180gr. at 960 f/sec. are the same?
I don't think so in my opinion. I rather not be shot by any and bullet placement is of the upmost importance but in a short barreled gun I rather be firing that .40 over a 9mm at non +P velocities.
PS Kyjim. Thanx again for that link you shared a while back. It has been very helpful.
Do you believe that a 9mm Corbon 125gr.+P at 1108 ft./sec (non +P velocities) and a .40 180gr. at 960 f/sec. are the same?
I don't think so in my opinion. I rather not be shot by any and bullet placement is of the upmost importance but in a short barreled gun I rather be firing that .40 over a 9mm at non +P velocities.
PS Kyjim. Thanx again for that link you shared a while back. It has been very helpful.
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Paper numbers don't count for squat in a life and death situation and you need to stop an attacker before he hurts you. The telling number is the amount of damage done to the target and the amount of energy transferred to the target from the bullet. If you have a through and through shot with both bullets then the only difference is the damage from hydrostatic shock and the size of the hole the bullet left behind. In that case points awarded to the 40 cal. The shooter that can put his rounds in the vital area is going to win no matter which gun you use but all else being equal the 9 is easier to shoot so points are awarded to the 9 MM.
Bullet types weren't mentioned either, HP, SP, FP, RN. Kind of like asking what is better a Chevy 1/2 ton pickup or a Ford 3/4 ton pickup. Better for what? If I am hauling light but bulky packages around town give me the Chevy, If I am hauling a load of fertilizer from the feed mill to the farm give me the Ford.
In fact give me a Ford pickup and a colt 45 and lets party.
Bullet types weren't mentioned either, HP, SP, FP, RN. Kind of like asking what is better a Chevy 1/2 ton pickup or a Ford 3/4 ton pickup. Better for what? If I am hauling light but bulky packages around town give me the Chevy, If I am hauling a load of fertilizer from the feed mill to the farm give me the Ford.
In fact give me a Ford pickup and a colt 45 and lets party.
I should have said colt 45 SAA, my drinking days are long gone behind me. Actually I quit drinking and smoking when I got serious about shooting. Party means burning powder and shooting at small objects at ridiculously long distances for the gun I'm using.
Put a rack of ribs with some good cajun BBQ sauce on the grill and heat up some cowboy coffee in the old tin percolator, you get your PBR and we can do the second best thing after shooting and fishing. Talk about shooting and fishing.
Put a rack of ribs with some good cajun BBQ sauce on the grill and heat up some cowboy coffee in the old tin percolator, you get your PBR and we can do the second best thing after shooting and fishing. Talk about shooting and fishing.
Brian Pfleuger
Moderator Emeritus
Maromero said:
That's an apples to oranges comparison. The only equal weight bullet in those charts is the 135gr Hydro-shok. Given equal weight, it's clear to me that the 9mm has an advantage over the 40SW when reducing barrel lengths. After all, your original question was:
Maromero said:
The answer to THAT question is, they don't. In fact, the 40SW seems to be at a disadvantage in that regard.
The question of whether this or that caliber is "better" is different than what you asked. Frankly, I see no reason to be shooting ANYTHING out of a 2 inch barrel, so the whole exercise is pointless beyond a "Hm, that's interesting" point of view.
I'll stick with the 1286 (chronographed)fps that I get from 125gr Speer Gold Dots in my 3.46 inch barreled 357sig, thank you.
Jim Downey
New member
I haven't been around much the last couple of weeks (life intervenes), but just wanted to say that it's a cool thing to see people using our data in intelligent ways.
Cheers to all!
Jim D.
Cheers to all!
Jim D.
Velocity in any firearm depends on two factors:
Factor one is the relationship between powder charge and bullet weight. More powder make bullet go faster.
Factor two is the 'expansion ratio' which is the ratio between the space inside the loaded round and the total volume of the interior of the case and the interior of the bore to the muzzle. The more expansion, the more 'pushing' on the bullet and therefore more velocity. Longer barrel make bullet go faster.
Low case capacity cartridges tend to loose the expansion ration factor less as barrel length is cut down. Straight sided cases have the same sort of advantage.
So whereas shot placement is paramount, one desires as much horsepower as possible in a carry gun, be it open belt holster or concealed. Me - being of the 'heavy bullet' faction - favor whatever round delivers the most momentum to the target; presuming that loading is safe and reasonably controllable. Other opinions differ; but they're wrong, of course.
Factor one is the relationship between powder charge and bullet weight. More powder make bullet go faster.
Factor two is the 'expansion ratio' which is the ratio between the space inside the loaded round and the total volume of the interior of the case and the interior of the bore to the muzzle. The more expansion, the more 'pushing' on the bullet and therefore more velocity. Longer barrel make bullet go faster.
Low case capacity cartridges tend to loose the expansion ration factor less as barrel length is cut down. Straight sided cases have the same sort of advantage.
So whereas shot placement is paramount, one desires as much horsepower as possible in a carry gun, be it open belt holster or concealed. Me - being of the 'heavy bullet' faction - favor whatever round delivers the most momentum to the target; presuming that loading is safe and reasonably controllable. Other opinions differ; but they're wrong, of course.