The Long and the Short of It

M

MoreCowBell

New member
I alternate carry between 5" 45 and 3" and between 4" 357 and 2-1/4"
I hear all the time that the short barrels lose so much velocity that ammo choice needs to reflect that. But I see little if any real data on the subject.

So yesterday I loaded up a 5" and 3" 1911, a Glock 22 and 27, an a 4" S&W Model 65, a 2-1/4" SP 101 in 357 and a 1-7/8" 38 Airweight Smith.
Plus 18 varieties of ammo, mostly various PD HP rounds, what wasn't magnum mostly +P.
Went to the range and chrono-ed all that stuff at ~10', three rounds each.

According to my results there is about a +/- 10% velocity drop between the long and short but the difference between light and heavy loads was inconclusive.

I'd like to also calculate impact force before I tabulate and post the data.
Anybody got the formula for getting lbft from bullet weight in grains and velocity in fps?

Thanks
cb
 
I'm very curious and don't want to sound condescending or rude, but, why would the difference in the velocity of a round vs. long or short barrel gun be so important. I would think that perhaps in competition it could be a factor but it appears that these guns you mentioned are personal defense weapons. I would be surprised if these calibers didn't stop a perp in his tracks regardless of which barrel length was used. And from most everything I have read, most gun battles are done at what I would term close range.

Again, I'm just looking to get educated and hopefully learn something new.
 
For a good study of the effect of barrel lenght on various cartridges, see http://www.ballisticsbytheinch.com/

They did an excellent job providing some solid information about cartridge performance. For the most part, it appears that most handgun ammo is optimized for a 4" barrel. Velocity losses are not always linear either.
 
I alternate carry between 5" 45 and 3" and between 4" 357 and 2-1/4"
I hear all the time that the short barrels lose so much velocity that ammo choice needs to reflect that. But I see little if any real data on the subject.

So yesterday I loaded up a 5" and 3" 1911, a Glock 22 and 27, an a 4" S&W Model 65, a 2-1/4" SP 101 in 357 and a 1-7/8" 38 Airweight Smith.
Plus 18 varieties of ammo, mostly various PD HP rounds, what wasn't magnum mostly +P.
Went to the range and chrono-ed all that stuff at ~10', three rounds each.

According to my results there is about a +/- 10% velocity drop between the long and short but the difference between light and heavy loads was inconclusive.

I'd like to also calculate impact force before I tabulate and post the data.
Anybody got the formula for getting lbft from bullet weight in grains and velocity in fps?
Click to expand...
Handgun velocities will drop as the barrel lenght shortens almost without exception, although powder an bullet choice can ususally help you get the most out of your shorter barreled pistols. With short barrels I would suggest a faster burning powder pushing a light bullet will give you the highest muzzel energies. Bullet drop information can be found in almost all reloading manuals. To calculate muzzle and downrange energy in foot pounds use the following formula. (Bullet Weight) X (Muzzle Velocity) Squared / 450,411

F. Prefect
 
My own belief is that the shorter the barrel, the faster the powder and heavier the bullet you want. You want to maximize the pressure buildup while the bullet is still in the barrel. The need for a fast powder in this respect is obvious, the need for a heavy bullet perhaps less so - the heavier bullet will allow greater time for pressure to build up and get more out of the round than just a loud boom and lots of flash.
 
I would be surprised if these calibers didn't stop a perp in his tracks regardless of which barrel length was used.
Click to expand...

Humph. I'd be surprised if they did. Unless you get a solid heart or head shot, NO, I repeat, NO handgun round is a reliable stopper.

As for velocities - yes, you do lose some velocity with shorter barrels. However, there are several CD rounds specifically made for short barrel guns. In general, the heavier bullet is better. Again, however, there are exceptions - there are lightweight bullets specifically designed to penetrate.

Nobody wants to be shot with anything, and the differences in the barrel lengths you mention will be negligible. Pick an ammo that shoots to point of aim and that your gun handles reliably.

As always - Shot placement is king.
 
CWPinSC

45Gunner
I would be surprised if these calibers didn't stop a perp in his tracks regardless of which barrel length was used.
Click to expand...

Humph. I'd be surprised if they did. Unless you get a solid heart or head shot, NO, I repeat, NO handgun round is a reliable stopper.
Click to expand...

I agree with CWPinSC.

All defensive handgun cartridges are underpowered. That is one reason that most training teaches to shoot multiple times to the center of mass to stop the threat. No one knows how long the threat will continue even if the shooter places perfect heart shots. It may be 10 seconds more that the threat can fight and shoot you.

Even though we know intellectually that what we have seen hundreds of times in movies and TV shows is fiction; we still tend to internalize those to some extent into our expectations.

Train to use movement, cover, and concealment in defensive shooting. Do a few "what is" scenarios where the threat is still a threat after you have fired two or three COM hits. What do you do?

MoreCowBell,

A rough rule of thumb is if you have a 10% loss of velocity that will equal about a 20% loss of energy.
 
velocity squared X bullet weight in grains / 450450 = ft/lbs energy.
Click to expand...

I believe the coefficient is actually 450,340 but I'll look it up and correct this post if I'm wrong....

I stand corrected, I used two seperate energy calculators and did the formula in reverse to get the coefficient used, it is 450450
 
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Great stuff. Thanks for the comments.
I've looked at ballisticsbytheinch but I got lost in there plus they didn't really match up with what I carry.
My main goal was to see if light 'n fast or heavy 'n slow retained power better in the shorties.
Yes all handgun ammo is underpowered, all the more reason to get as hard a hitter as you can.
Yes most gunfights are short range. This wasn't about bullet drop it was about dropping the BG. That's why I used a 10' range.

I ran the 45 trials data quickly and got the following energy loss factors short vs long: 79%, 84%, 61%,76%, 79% and 75%.
These were for Fed HST+P 230g, Aguila 230 FMJ, WWB 230 FMJ, Cor-Bon Powr Ball 165 +P, Rem Golden Saber 185 HPJ and Fed Low Recoil 165 GEEXPAN Expanding FMJ, repectively.

Sorry I don't have the time tonight to make a table but I'll go ahead and add that the energy for each in lb/ft2 long/short was as follows:
447/352, 353/295, 447/375, 503/381, 452/356 and 441/329.

I'll try to get the 357, 38 and 40 S&W figured and tabulate all this stuff before the weekend. So far the only conclusion I have is you get what you pay for.
I'll be interested to see how the 40 and 357 match up with the 45.
I guess I'm just tired of seeing endless threads of ammo arguments with little or no data supporting it. In the engineering world I've seen a lot of intuitive opinions refuted once the data hit the table.
cb
 
I'm very curious and don't want to sound condescending or rude, but, why would the difference in the velocity of a round vs. long or short barrel gun be so important. I would think that perhaps in competition it could be a factor but it appears that these guns you mentioned are personal defense weapons. I would be surprised if these calibers didn't stop a perp in his tracks regardless of which barrel length was used. And from most everything I have read, most gun battles are done at what I would term close range.

Again, I'm just looking to get educated and hopefully learn something new.
Click to expand...

Among other things, the longer the barrel, the greater the velocity. Other factors, such as how fast the powder burns and what pressure it develops and bullet weight all play a part.

Let's take some "standard" examples. Federal 158g JHP and 125g .357 Mag ammo.
........... 158gr .... M/E .... 125gr .... M/E
6 .......... 1465 .... 753 ...... 1702 .... 804
5 .......... 1373 .... 661 ...... 1571 .... 685
4 .......... 1293 .... 586 ...... 1511 .... 634
3 .......... 1194 .... 500 ...... 1255 .... 437
2 ........... 858 ..... 258 ....... 949 ..... 250

Thus, a 158gr JHP from a 2" barrel only delivers 258 ft-lbs, while the same round from a 6" barrel gives 753 ft-lbs.

If, for instance, the JHP designed used does not expand reliably under 1150 fps, then out of a 2" barrel it probably will not expand. At 1465 it may mushroom perfectly, causing more trauma (bleeding/shock) to the body.

Accurate shot placement is king.
Penetration is queen.

258 Ft-lbs is about the same as a .38 Special +P out of a 4-inch or 6-inch barrel. If your shot placement disrupts something vital, your opponent will shut down quickly.
 
Sorry guys. I crunched the numbers but instead of putting them in a spread sheet I just laid them out in a post on my local gun forum. When I copied them over here they got jumbled because apparently there's a different forum engine and it doesn't give as wide a surface.
If you're interested in seeing them unjumbled you are welcome to go to Carolina Gun Talk/General Firearms Discussion/Short Barrel power loss trial/Post #6.
A couple immediate observations:
1) There is no appreciable difference between light and heavy loads in 2" and 4" barrels (3 and 5" in the semis but they measure different, so same difference more or less). Most of the best power conservation was in the 'tween size bullets.
2) I was interested to see that the Hornady LeverRevolution rounds performed admirable. Popular opinion is that since they're rifle rounds they wouldn't develop good power in a revolver.
3) 38 Specials stink compared to 357 magnum, even when they're +P.

So, without data, theory is not fact.
I'm just saying.

So here's the raw data:
SURVEY SAYS:
Velocity Energy Energy Diff
ft/sec (short fps) lbs/ft(short lbs/ft)
.45 ACP Llama 5"(Kimber Ultra CDP 3")

Federal HST +P 230grain 936 (831) 447 (352) 79%

Aguila 230 FMJ 832 (761) 353 (295) 84%

Winchester White Box 230 FMJ 804 (734) 447 (275) 61%

CorBon Pow'r Ball 165 +P 1172 (1021) 503 (381) 76%

Remington Golden Saber 185 HPJ 1049 (931) 452 (356) 79%

Federal Low Recoil 165 Expanding FMJ 1097 (948) 441 (329) 75%

357 Magnum S&W 65 (4" Ruger SP101 2-1/4")

Remington 180gr SJHP 1173 (1053) 549 (443) 81%

Winchester 158 JHP 1242 (1090) 541 (417) 77%

MagTech 158 SJSP 1099 (993) 424 (346) 82%

Hornady 140 FTX LeveRevolution 1279 (1185) 508 (436) 86%

Speer Gold Dot 125 GDHP 1396 (1268) 541 (446) 82%

38 Special S&W 65 4" (S&W 442 1-7/8")

Federal HydraShok 129gr +P JHP 944 (885) 260 (219) 84%

CorBon 125+P JHP 970 (898) 261 (224) 86%

Hornady 110 FTX +P 1029 (934) 258 (213) 83%

40 S&W Glock 22 5" (Glock 27 3")

Winchester Personal Protection 165gr JHP 929 (885) 323 (287) 89%

Federal 155 Hydra Shox JHP 1175 (1100) 475 (416) 88%

Speer Gold Dot 165 GDHP 1134 (1049) 471 (403) 86%
 
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Thanks for the data MoreCowBell. I think your data once again proves there is a significant difference in long and short barrels.

I often carry a .45 and was interested in the especially large difference in the Winchester White Box in the long and short barrels.
 
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