In this review, I would, like to bring up a few points that I think are being overlooked in the "light-n-fast" discussion.
#1 Comparing all of the "lightweight" rounds in one basket is sort of
like saying "All 230 grain JHP's are the same".
There are design differences that will contribute to or detract from,
penetration and other performance factors.
#2 There are other "Light and Quick" rounds out there that will get the job done.
The FN Five-Seven is a good example.
The newer Armscor 22tcm is also an interesting newer development.
We can get into details like sectional density of the smaller caliber
rounds and such, but in a real world scenario, I wouldnt want to be
hit by any of them.
In Fact, the Five-seven is currently in service with military and police forces in over 40 nations.
If FN can design their cartridge to penetrate & expand in a reliable fashion
so can other manufacturers.
On to the review:
Lets look at the specs vs a few other options.
Liberty Halo 45ACP Weight: 78gr Velocity: 1900 FPS
Armscor .22 TCM at 40 grains at 2000 feet per second
FN Five-seven <5.7×28mm> 40 gr at 1,700 FPS
Personally speaking, If I am going to go with one of these,
the fact that I can load the Halo into my XDS and 1911 without
mods and/or purchasing another pistol is a deciding factor.
That, and the 45ACP Halo is twice the weight at the same velocity.
I know that a water jug isnt the best testing medium, but holy energy-dump batman!
The 45ACP Halo decimates a jug.
I ran a 1/2 a box thru my Series 70 Gold Cup and the other 1/2 thru
my Springfiels XDS. Both digested the ammo without fail.