.40 S&W Carbine?

B

bqglock

New member
Anyone chrono'd a .40 sw out of a 16.5 in barrel? I'm curious on velocity increase. I'm thinking about buying a .40 carbine and am wondering what velocity increase (if any) I might experience.
 
I've heard estimates of 10-15% increase in muzzle velocity, based on 9mm carbines.

Shouldn't be too far different with a .40, I would think.
 
A .40 in a carbine brings the power and velocity up to a 10mm. Do a little research on the 10mm, and why the FBI no longer uses it. Basically its good on larger animals but bad for anti personnel
 
ace4059 said:
A .40 in a carbine brings the power and velocity up to a 10mm. Do a little research on the 10mm, and why the FBI no longer uses it. Basically its good on larger animals but bad for anti personnel
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The reason the FBI went away from the 10mm has nothing to due with it being "bad for antipersonnel".
They quit using it because their agents couldn't control the power. SW reduced the loads and then realized they could use shorter cases with the reduced loads... Hence the 40SW was born.
The 10mm is a fantastic round if you know how to control the gun.
Most modern 10mm is loaded to the reduced power levels of 40SW so unless you load your own or buy expensive premium ammo there's not much difference.
 
peetzakilla said:
The reason the FBI went away from the 10mm has nothing to due with it being "bad for antipersonnel".
They quit using it because their agents couldn't control the power. SW reduced the loads and then realized they could use shorter cases with the reduced loads... Hence the 40SW was born.
Click to expand...

Yes that is true, but it is only part of the reason.

Read the paragraph below this line from from here; It refers to the .40 cal in the Kel Tec sub 2000.

So why not the .40? Well, when you put the .40 S&W in a Rifle form, it has the power of a 10mm. Now the 10mm is a powerful round. The FBI liked this, when it was invented in 1984. In fact it was too powerful, and had to be scaled down (hints the FBI lite loads). Some may remember the problems the FBI was having in the late 80's /early 90's, so they switched to the .40 S&W. The 10mm was a good round when loaded to 950 fps. They basically had to scale it down because it was over penetrating (plus too big of guns, and too powerful for smaller agents to handle), and the bullet was not delivering the kinetic energy to the target. The bullet would just pass through. So when they developed the .40 cal, it was a slower fps and it delivered the energy to it's target. The .40 is basically a 10mm lite. So to the point, when you use a .40 S&W in a Rifle, it will be too powerful and go right through, not stopping the target as quickly.
 
Well, I'm not about to rehash all the arguments about over-penetration and "stopping power" all over again. Suffice it to say that I do not subscribe to your theories.
 
^ I haven't decided yet I wanted to see if getting one would be worth it. I have a glock 32 with a lone wolf .40 barrel and wanted a long gun. just thought i would get one with ammo i already have other than .22 and no long guns are made in .357 sig :(
 
bq - I have a Beretta CX4 in .40S&W. Through the chronograph, the carbine w/ 16.6" barrel was approx. 250fps faster than the PX4 w/ a 4" barrel. This increase was almost the same in 2 different bullet weights.
 
I have an AR-15 in .357 SIG. Ron Williams made the DI upper for me. LW lower that uses Glock 31 mags. 9" barrel.

re: the 10mm. I'm sure they were having over penetration issues with the original full power ammo. The Norma loads were 200 grains. But it's important to remember that handgun ammunition has experienced a titanic shift in the last 10-15 years. These are the Golden Years. When you look at Gold Dots, and Critical Defence, and PDX1 Bonded, and Golden Sabers, and CorBon DPX, etc, etc, etc... I'm quite sure they could develop a full velocity 10mm load that would give just exactly the right amount of penetration. But they would still have to face the larger grip. It could probably be done if .40 S&W wasn't working just fine. Look at how SA was able to somehow make a .45 ACP version of the XD that feels like a .40 in your hand. If the FBI wanted to buy such a thing, I'm sure they could do the same thing with 10mm.

Gregg
 
Funny you should ask----I just bought an ATI JR (Just Right) Carbine in .40 cal. I have only shot it for function and don't have a chrony, but it does seem to pack (seat of the pants) a little more punch. For the record, it is a very nice carbine and uses Glock mags, I have a Glock 22, so all the mags I have will fit. Saves on ammo and mags. It has a picatinny rail system as well as a flat top configeration so a lot of AR stuff fits as well.
 
The way I read the chart in "Ballistic by the Inch", it looks like the lighter bullets get more boost from the barrel length. 180gr. don't speed up too much. 135gr. speed up quite a bit.
 
The way I read the chart in "Ballistic by the Inch", it looks like the lighter bullets get more boost from the barrel length. 180gr. don't speed up too much. 135gr. speed up quite a bit.
Click to expand...
That is true. I've done lots of tinkering with such loads for my carbines. With a blowback action you gets lots of increase with the light bullets only. The heavier ones don't get much of an increase, though you do get less noise and flash.
 
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