327 or 5.7 x28 what is you choice

[BillCA]

Energy is irrelevant in a discussion about pistol performance. Energy does not wound.

Care to expound on that statement?
How is energy (momentum) not relevant? What is relevant in your opinion?

 

[DmL5]

- A 27 grain Jacketed Hollow Point that is hard-pressed to reach 1,600 fps? What exactly do Five-Seven shooters expect from a 27 grain varmint bullet in a self defense situation?
- A 40 grain V-Max? Again... do you really think the V-Max is a good choice here? It is designed for instantaneous, explosive expansion. Horrible, horrible wounds might result, but I doubt they would be debilitating to an attacker, unless a head shot was made (and then you'll have some additional explanations you'll have to give to LEOs).

- FN's factory SS195 (with a 28 grain bullet) produces a muzzle velocity of 1950 to 2050 ft/s. It uses a plain hollow point bullet designed to tumble quickly. It doesn't use a varmint bullet.
- FN's factory SS197 (with a 40 grain V-Max bullet at 1700 ft/s) actually manages to penetrate nearly 11 inches in ballistic gelatin, according to testing by Brassfetcher.

Both of FN's civilian ammunition types are watered down and perform substantially worse than other ammunition available to civilians. EA produces 5.7x28mm cartridges that push heavier bullets at higher velocities. In fact, their Exterminator cartridge pushes a bullet 60% heavier than FN's SS195, at the same velocity of roughly 2000 ft/s. Their lighter bullets (such as the 28 grain S4) produce muzzle velocities of nearly 2600 ft/s from the pistol barrel and over 3050 ft/s from the PS90 barrel.

http://www.eliteammunition.net/57_ammunition.html

with the wrong bullet construction

A number of different bullet types are available in 5.7x28mm ammo.

Care to expound on that statement?
How is energy (momentum) not relevant? What is relevant in your opinion?

This article is a good start:

http://www.firearmstactical.com/pdf/fbi-hwfe.pdf

 

[darkgael]

Interpret

The Five-Seven pistol slings bullets weighing one third that of the .327 Magnum, but is pushing only marginally more velocity than the .327 - with the wrong bullet construction!

No one has said that the 5.7X28 is as effective or as powerful as the .327.
Indeed, the edge is decidedly for the .327.
What has been written about the 5.7X28 is, as far as I can see, in response to statements about that round which show a decided lack of familiarity with what is available and how it performs. We see frequent references to old data (if it is referring the the 28 grain bullet chances are it is old and limited data. Dated data.) The best rounds available - and which have been available for some years now - are those already mentioned as produced by Elite Ammunition.
I have read through many criticisms of the 5.7 and not one of the critics has ever referenced the top shelf Elite ammo.
Lack of familiarity with what is out there.
The .327....great round.....not part of the argument.
Pete

 

[ET.]

357(sig) for me

I use my Glock 27 as a 357sig utilizing a Storm Lake barrel and the same mags. I carrry it loaded with JHPs and can't be happier with it. I wish I could tell you how well it drops BG's but I have never shot one (& hope I never have to).

 

[BillCA]

This article is a good start:

http://www.firearmstactical.com/pdf/fbi-hwfe.pdf

From what I see, the author dismisses energy (momentum) in the discussion of "knock down power" -- completely dismissing the idea as against physics. But yet, in a later section, the author says...

A shot from the side through an arm must penetrate at least 10-12 inches to pass throught the heart. A bullet fired from the front through the abdomen must penetrate about 7 inches in a slender adult just to reach the major blood vessels in the back of the abdominal cavity. Penetration must be sufficiently deep to reach and pass through vital organs, and the permanent cavity must be large enough to maximize tissue destruction and consequent hemorrhaging.

Thus, penetration is key. The major organs of the human body can be tough and resilient. The heart can actually be penetrated without tearing or rupturing the tough and elastic tissues. In such cases, depending on projectile sizes, the heart may not even lose very much blood.

In order to penetrate these tissues a finite amount of energy (momentum) is required. But even using a .45 bullet and the bare minimum energy needed to penetrate 7-12 inches still makes energy a factor in selecting the ammunition you will use.

One of the key points made in the article is this:

It is essential to bear in mind that the single most critical factor remains penetration. While penetration up to 18 inches is preferable, a handgun bullet MUST reliably penetrate 12 inches of soft body tissue at a minimum, regardless of whether it expands or not. If the bullet does not reliably penetrate to these depths, it is not an effective bullet for law enforcement use.

By this commentary then, we'd be find arming officers and the public with a 4-inch barreled .32 H&R Magnum with a 98 grain SWC at 1100 fps. This will reach the Vena Cava in frontal shots and has the ability to reach the heart from oblique shots. (As reported by coyote shooters and two small deer under 150lbs taken at close range with a .32 H&R.)

Bullet energy (momentum) as measured at the muzzle or at 25 yards is a fair indication of the ability of the round to meet the penetration needs of the shooter. It thus becomes an important factor in selecting ammuntion for defensive use.

This report was written 21 years ago (1989) and at that time the author was correct in stating that JHP ammo expansion reliablity was less than 70%. However, today's SD ammo is much improved with newer designs. Bullet designs now allow for reliable expansion at lower velocities than in the 1980's. In addition, some rounds that expand reliably still use produce considerable muzzle energy so that the expanded bullet - with its greater frontal area - can plow through tissues up to 12-17 inches.

All this adds up to one thing. While energy doesn't predict the ability for an instantaenous stop, it does have a tremendous influence on the ability of the bullet to perform the "work" of ripping up tissue as it passes through sections of the body.

It is an error to say that "energy doesn't matter". It matters a great deal when selecting your defensive ammo.

 

[DmL5]

Bullet energy (momentum) as measured at the muzzle or at 25 yards is a fair indication of the ability of the round to meet the penetration needs of the shooter.

Not at all. I could give you dozens of examples of bullets with low energy penetrating deeper than bullets with higher energy, due to other factors. Here is just one comparison:

A handloaded 85 grain .32 ACP with only 137 ft lbs muzzle energy penetrated 13.9 inches in ballistic gelatin: http://www.brassfetcher.com/32acp Handloaded 85gr Hornady XTP.html

An 84 grain Geco 9x19mm with 325 ft lbs muzzle energy penetrated only 11.7 inches in ballistic gelatin: http://www.brassfetcher.com/9x19mm Geco 84gr +P Action 1 Bare Gelatin.html

The 9mm loading penetrated significantly less than the .32 ACP, while it produced almost three times the muzzle energy. In conclusion, simply looking at energy numbers gives you an incredibly poor indication of a bullet's actual penetration depth.

It is an error to say that "energy doesn't matter". It matters a great deal when selecting your defensive ammo.

It does not matter at all. In the process of selecting ammo one should simply follow published testing, where the penetration and expansion numbers are clearly indicated. Two bullets with equivalent muzzle energy can (and very often do) give entirely different performance in actual testing.