spyderco monkey wrote:
I'm a huge fan of the a high velocity cartridge that works in a 9mm, but the TCM has one serious issue, which is the use of the truncated bullet design.
By using such a short projectile, it won't be able to tumble, which is the only way these types of calibers can really perform. The reason the 5.7 is so long, and works as well as it does, is that it's projectile is over .80" long, and tumbles.
It appears the TCM uses bullets very similar to the .22lr, while the 5.7 uses actual rifle bullets.
I will be at SHOT and will find out more.
The Truth About Guns wrote:
The .22 TCM is a funky cartridge. It’s designed from a necked down piece of 9mm Parabellum brass to take a .223 caliber bullet (the same bullet used in 5.56x45mm NATO rifles) and fire from a handgun.
source: http://www.thetruthaboutguns.com/2011/1 ... m-firearm/
The way I read this was it uses the same bullet in terms of dimensions (size, weight, length, etc)
His information is incorect hearsay- the cartridge is made of shortened 5.56 brass, not 9mm as he states. As for the projectile, the designer Frede Craig describes it as a truncated projectile (which is how it works in the 9mm).
Furthermore, there is direct visual evidence- just look at the cartridge and you can see its very similar to the SJHP from a .22lr/ .22mag, and not a Spitzer/5.56 style rifle bullet.
Here's an even better image, but too large for ZS http://1.bp.blogspot.com/-MSg-F8_RxIo/T ... G_0692.JPG
5.7 doesnt fragment on impact? with the velocity it has, I suspect it does, unless its made out of bronze or copper or some shit.
the SS197 V-max does indeed expand and fragment, and is decently effective. But to get the 9mm/45 level of performance it is capable of, the SS195/SS190, tumbling projectiles are needed. It just makes sense really- whats better, a .22 expanding to .45, or a .22 tumbling to .80"? Brassfetcher in his testing rates the 5.7x28 tumbling ammunition as more effective than the .45.http://www.brassfetcher.com/5.7x28mm%20 ... ummary.pdf
All this being said, I'm super hoping I'm wrong about the TCM as I would love there to be more competition with the 5.7x28, but just from looking at what info is available now, I think 5.7 is superior (and 6.5 CBJ owns all!
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