# .40 vs .45



## bryan1966 (Mar 3, 2008)

Anyone care to comment which is the better round.


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## 220combat (Oct 26, 2007)

You're setting yourself up for a debate about who LIKES which one better. When you ask which is better, what do you mean by better?


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## hawcer (Feb 22, 2008)

5yrs ago my answer may have been different....but today,I would say the 40s&w is the better choice(mainly due to ammo prices).

I don't think we need to argue about which one makes a bigger hole....most people don't prefer any size hole in them!


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## babs (Nov 30, 2007)

The newbie here chiming in... 
Ok.. It's all speculative so if I'm totally wrong I would not be surprised.. So just ignore me. :mrgreen: Just impressions:

Pro's for the .40:
- Typically more round capacity in the mag for comparably sized guns
- Don't know or think there's much price difference per round though
- Availability.. I imagine with the big law enforcement popularity of .40 S&W which indicates more availability of LE type pistols chambered in .40 to choose from than .45 in the market? ..possibly, not for sure on that. Appears new guns that come out chamber for 9mm, then work their way up to .40 and .357Sig then up to .45 GAP and then ACP. XD is one example.
- Grip size in semi-auto's, especially in relation to capacity.

Pro's in favor of the .45 ACP:
- Maybe (keyword) the .45 has a bit more bump behind it as a defensive round.
- Accuracy might be slightly better for comparable round brand/type? I dunno and won't claim to have any factual evidence to support either round as more accurate or dependable.
- The classic 1911 round so pistol choices broaden your options if wishing for your next .45 pistol.
- Typically guns chambered / designed for .45acp must be built uh... a bit more robust/strong.

In terms of ballistics, it may be a wrong assumption but people get the impression the .40 is a "nice compromise" for more knock-down power similar to a .45 in a smaller round slightly larger than the 9mm but still not as big as a .45acp.

ok.. so to try to contribute something of actual value from probably someone else that actually does know what they're talking about.. Here's a good read on at least a comparison of the .45 and 9mm...
http://www.hipowersandhandguns.com/9mm%20vs%2045.htm

.... In closing.. I'd hate to be the recipient of any or either of the above mentioned. .. ouch!


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## Joeshwa24 (Nov 14, 2007)

This is a simple question of prefrance... I own both and I shoot both as crazy as this sounds I struggle a little more with the .40S&W than the .45acp. The best way I can describe it is that the recoil on a .45acp is more of a thud and the recoil on the 40 smith is more of a snap... but again all prefrance


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## TOF (Sep 7, 2006)

They both go boom and if aimed properly make holes in what you wish to have holes. If that is a bad guy they will probably stop being bad.:numbchuck:

:smt1099


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## Baldy (Jun 21, 2006)

It's what you shoot the best and are more comfortable with. I have both and do better with the .45 as it has more of a push than a snap. I have more trouble with the .40 because of the trigger than the recoil.


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## 220combat (Oct 26, 2007)

My glock 27 in 40 is a hard snap, the gun really jumps. My Sig 45 is a dream to shoot. The Sig probably weighs twice as much as the Glock which is a big difference


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## JeffWard (Aug 24, 2007)

Technically:

The .40 is a flatter shooting, faster, lighter bullet, that fits in frames designed originally for 9mm, allowing a smaller grip size (therefore growing in popularity for competetive shooters).

The .45 is a bigger, heavier, slower bullet, so it will drop more over extended range than a .40. The size of the .45 case mandates a larger ejection port, and larger grip, tending to make it less effective reliability-wise in small concealable guns.

Lighter, faster bullets MAY be deflected MORE if they encounter clothing, bone, twigs, wall-board, etc, on the way to a target than a heavier .45. But then, a faster .40 may penetrate angled vehicle glass better???

The heavier bullet .45 will tend to penetrate deeper than a .40, but the added velocity of the .40 (due to weight) can penetrate MORE, depending on the circumstances of the test!!! A favorite line of .45 proponents is: "a 9mm or .40 MAY expand to .45 inches, but a .45 will NEVER shrink to 9mm."

In the end???

BOTH are proven defense rounds. BOTH are more expensive than 9mm. Neither wil stop a man any more surely than a well placed 9mm.

My OPINION...

If you're going to carry a FULL sized gun for defense, carry a .45. No one has proven a .40 or a 9mm BETTER, only AS GOOD.

If you're going to carry a compact gun for CCW, carry a 9mm or a .40. Nobody builds an EXTREMELY reliable 3" barrel, 1" thick .45ACP. There are many good 3X1" 9mms and .40s. I sold my .40 for a 9mm because I feel BOTH are fine for defensive uses. The 9mm is much cheaper to practice with, and the 9mm is easier to keep on target with follow-up shots.

NO handgun round is a guaranteed one-shot-stop gun. Even a .44Mag.

Any guns is capable of a one-shot-stop, if you can "shut off the switch" with a Central Nervous System hit. If you cannot hit a CNS size target on the range 8 out of 10 times, you're only praying in a fight. Carry what you can SHOOT, and shoot enough to be VERY GOOD.

JW


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## hideit (Oct 3, 2007)

recently 3 state police depts went to the 45 and one of the reasons was that the 45 penetrated car glass better than the 40


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## DevilsJohnson (Oct 21, 2007)

I personally like the 45 ACP more for a carry load. Is it better? It is for me. but the 40 round is fun to shoot.:smt023


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## submoa (Dec 16, 2007)

JeffWard said:


> The .40 is a flatter shooting, faster, lighter bullet, that fits in frames designed originally for 9mm...


Jeff identifies the biggest problem I have with the .40 round.

I assume that in designing a handgun, especially for CCW, weight and size are important criteria. Therefore, you want to use the minimum amount of material in building a gun that will meet your requirements for strength and durability.

Logically, to make a gun designed for 9mm work with a .40 round, you either need to remove material - weakening the gun, or dimensionally stretch the design to fit. Either way, you end up with a compromise.


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## Mike Barham (Mar 30, 2006)

_All_ defense guns are a compromise. If we didn't have to compromise, we'd all carry around M4geries or Steyr Scouts or Remington 1100s, right?

.40 rounds fit in guns with a 9mm cycle length. There are many .40s based on 9mms that have slightly beefed up slides and such. Look at the Browning P35 or the SIG P239. But these guns are still more compact, especially in the grip area, than the equivalent .45.

.40 does have snappy recoil, as a consequence of its higher operating pressures. But in return you get a smaller gun, and/or one that holds more ammo than the .45. I think that's a good trade, since I don't find the .40 unmanageable in anything but subcompact pistols.

The .45 is a low-pressure round that is pleasant for experienced shooters to fire. .45 pistols will probably last longer than .40s due to lower pressures and slide velocities. But most people don't shoot any gun enough to wear it out.

I think there's about a nickel's worth of difference in the "stopping power" of the .40 versus the .45. The .40 performs exceedingly well.


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## submoa (Dec 16, 2007)

An example of a design compromise to worry about is the famous lack of full case support in early Glocks with calibers > 9mm. Subsquently fixed.

Video of Glock 23 kB!: 




What is a kB!?
Coined by firearms journalist Dean Speir, kB! is shorthand for "kaBOOM!," which is the written representation of what happens when one has a catastrophic explosive event in one's Glock. (See also Sidebar Addendum.)

What causes a kB!?
Catastrophic failures may be caused by a variety of problems, but in general a kB! is as a result of a case failure. The case failure occurs when pressure inside the cartridge increases to the point that it cannot be contained by the case and the material of the case fails, allowing hot gases to escape from the ruptured case web at damagingly high velocities. The resulting uncontained forces can blow the magazine out of the gun, destroy the locking block, cause the tip of the trigger to be snipped off, ruin the trigger bar, rupture the barrel, peel the forward edge of the slide at the ejection port up, and do other nasty things. In general, Glocks tend to contain case failures fairly well, but under some circumstances they can cause injury as well as damage to one's gun. At least one Federal LEO has been injured in a kB! involving a Glock 21 and a Winchester factory overcharge. Additionally, there is some evidence of there being another cause of a kB!&#8230; a barrel failure caused by improper metallurgy.

Which Glock models are affected?
Speir has documented many instances of kB!s, all of them in the Models 20 and 30-something Glock (.40 S&W, 10mm and .45 ACP). And since the introduction of the Models 30-through-36, there have been incidents of kB!s in the 357 SIG (Models 31, 32 and 33) and the .45 ACP (Models 30 and 36) pistols as well&#8230; all with reloaded or remanufactured rounds by most accounts.

And until February 2004. Speir had no (as in zero!) confirmed cases of Glock kB!s in the 9 x 19mm (Models 17, 17L, 18, 19, 26 and 34, although there has been one such reasonably detailed anecdotal report), or the .380 ACP/9 X 17mm (Models 25 and 28). Then came the following from Todd Louis Green:

At the S&W IDPA Winter Championship this past Saturday (28 February) I personally saw a Glock Model 34 with its barrel split top from bottom all the way through the breech. The kB! occurred in front of many witnesses. The shooter was using factory PMC practice ammo.

I had my Canon D10 with me but felt it would have appeared unprofessional to ask for some photos or try to get contact info for the owner.

Anyway, that's the first 9 x 19mm Glock kB! I've ever seen, and with factory ammo no less!
And that is the first confirmed&#8230; a second source reported this as well&#8230; 9 x 19mm Glock kB!. And in January 2005, a second one has been reported as well. 
Why do kB!s occur in these Glock models?
Reports compiled by Speir from various independent laboratories are inconclusive as to one single cause for the catastrophic failures.

There do, however, appear to be several contributing factors which collectively may induce catastrophic case failures:

Firing out of battery. Most Glocks will do this to some degree, especially those improperly maintained. 
Significantly overpressure rounds. These occur mostly in homemade reloads or in commercially remanufactured ammunition, but have occurred in factory ammunition as well.

Lack of full case support in the critical area over the feed ramp of all large caliber (.40 S&W, 10mm, .45 ACP) Glock pistols. [See Annotation #5]

Ostensibly as a measure to promote feed reliability, Glock chamber mouths are slightly oversized. One can test this by removing the barrel from the Glock, dropping a factory round into the chamber, and observing that there is brass exposed at the six o'clock position. Take a fired case and note that there is a slight engraving if not actual bulge around the case web, which is most pronounced in the area of the case which, upon firing, was in the six-o'clock position. 
Use of personally reloaded or commercially remanufactured ammunition utilizing cartridge cases of indeterminable generation. Unlike most rifle handloaders, those who reload for handguns do not as a habit segment their fired cases by generation, and each time a case is re-sized for reloading, the brass "works" and weakens through enbrittlement.

kB!s have been documented with factory ammunition, but most of them occur with either commercial or homemade reloads.

Do kB!s occur in other guns or just in Glocks?
kB!s do, of course, occur in other guns, but no one appears to be keeping accurate statistics for most of them. Many 1911-style handguns have partially unsupported case mouths, and numerous case separations have occurred in these guns. Early .38 Super barrels were particularly susceptible, and the critical observer may have noticed the predilection among USPSA .38 Super competitors for full beards in an attempt to cloak the vestiages of what came to be known as "super face."

Respected firearms author Frank James, in 1994, documented a number of kB!s in HK USP .40 pistols, which do have fully supported chambers. (Also see this!)
What is the relationship between reloads and kB!s?
Most kB!s occur with commercially remanufactured or personally reloaded ammunition.

Successive re-sizing and firing of a case result in eventual weakening of the brass, increasing the probability of case failure. The partially unsupported chamber in the Glock exacerbates this problem.

"Hard crimping" or overseating of bullets, particularly in the .40 S&W, can cause dramatic increases in pressure almost to the same degree as a propellant overcharge. [See Annotation #3] Either alone or in combination with a weakened case, these factors can result in a kB!

Some people have also postulated a relationship between the use of cast lead bullets and kB!, arguing that buildup of lead in the chamber can lead to pressure buildups as well. The jury seems to be out on this one as a direct causation, but lead build-up will sometimes cause a round to not fully chamber, and as Glocks can discharge with the action not completely locked up ("out of battery," [see Annotation #4]), this can lead to a catastrophic failure.
What can I do to prevent a kB!?

Shoot only new factory ammunition out of your Glock. This is what Glock, Inc. recommends, as do several members of Glock-L. Shooting reloads voids your factory warranty.

Install a barrel with a fully supported chamber. Custom barrel makers include Bar-Sto Precision Machine and&#8230;

Briley Manufacturing 
Jarvis Precision 
Wilson Combat
&#8230;but as can be seen in the adjacent image, even this is not fool-proof if a Glock shooter is determined to over-charge a round! 
Avoid wherever possible .40 S&W ammunition manufactured by Federal Cartridge Company prior to November 1995. For related data, see Annotation #2, a part of this FAQ. 
At an October 1996 G.S.S.F. match on Long Island, one competitor with a Model 22 had simply switched to a .40 S&W Sigma barrel which he averred not only better allowed him to shoot lead because of the conventional rifling, but that the fully supported Sigma chamber significantly decreased the opportunities for a kB!

Note: This procedure is neither recommended nor authorized by Glock, Inc. or Glock Ges.m.b.H.

If I insist on reloading for my 357 SIG or .40-something Glock, what can I do to minimize the chances of a kB!?

Install a custom barrel. See 7B. 
Keep careful track of your brass. Load "Major Power Factor" loads only in new brass. Don't use range pickups. Don't shoot "hot loads" from used brass. Discard used brass sooner than you would normally. 
Use calipers or case gauges to keep your reloads within spec. Check for excessive bulging in the case web and make sure your bullets are seated to the correct length. Also check for excessive case thinning or bulging.

The propellant AA#5 [See Annotation #1] has been identified in a disproportionate number of kB!s, not only in Glocks but USP40s with barrels which do provide full case support. A number of Glock-L members have reported kB!s involving this propellant. It is not clear whether these kB!s are the fault of the propellant or the reloader, but it is clear that they are occurring in disproportionate numbers. As early as Fall '92 a source inside Glock, Inc. told Speir on background: "A lot of the blown up Models 22 and 23 we've been seeing has involved Accurate Arms #5&#8230; and damned if we know why."


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