You don't really know what I'm talking about when I mention the 2,000 FPS threshold, do you?
Sure I do, hydrostatic shock and all that
It's not an end all be all, and just doesn't come into play here.
The .223 or 5.56 fmj's are not effective at speeds under the velocity needed to fragment, which is about 2700+ fps. Repeating that term doesn't change physics, millions of dollars worth of govt. number crunching and field studies, or make a death ray out of an otherwise underperforming round.
There's a really big difference in the wounding characteristics of a 1,700 FPS projectile and a 2,400 FPS projectile.
Is there? If a .223 bullet fails to expand or fragment at 2400fps, is it going to be a significantly different wound pattern than an identical bullet that doesn't expand or fragment at 1700fps?
I don't think you yourself understand what you are referring to.
The "2000fps threshold" isn't the point when animals get blown inside out from the sheer velocity of a projectile.
Its when a projectile designed to expand or fragment at rifle velocities starts behaving differently upon impact, by expansion or fragmentation. If the projectile fails to expand or fragment at 2400fps, the "2000fps threshold" won't make it more effective than one going 1700fps.
From the book
Wound ballistics; basics and application...chapter 4.3, page 213.
https://books.google.com/books?id=q...#v=onepage&q=rifle velocity threshold&f=false
"There is currently no evidence for the existence of a velocity or energy threshold for conventional designs of handgun or rifle bullets above which different wound ballistics phenomenon would occur.
However, there is a velocity threshold at which the behavior of a bullet changes. Full metal jacketed bullets remained shape stable on impacting water or gelatin at velocities up to 500 to 600m/s. At higher velocities they begin to deform or fragment."
And yes, I have chronographed M193 out of my 7.5" SBR with an average velocity of 2,380. M855 is closer to your figure.
Ok, so you got an M193 to go 320fps UNDER the effective velocity of the round.
I go by what Ballistics by the Inch gives me in real world numbers.
http://www.ballisticsbytheinch.com/223rifle.html
Lastly, we citizens are not a military force voluntarily complying with Hague convention; why on God's green earth would I rely on ball ammo when I can run my 50 gr. V-max hand loads that clock 2,625 FPS and most definitely open up at that speed?
50 grain Vmax handloads?
you'd better have boutique bullets to get any kind of expansion.
Sounds pretty boutique to me
Regardless, they are completely irrelevant to the discussion as they cannot be obtained by anyone other than you.
"50 grain vmax handloads (that only I have)" is pretty vague and unverifiable.
On a lighter note however,
A Vmax might just be the ticket though, at that lower speed it might retain enough weight to get through into vitals.
I know after seeing what it did to a coyote at closer to 3100fps, I wouldn't trust my life to it stopping a large, enraged bad guy. Basically made a really nasty flesh wound and left me with one wounded 40lb coyote.
I'm not trying to engage insurgents at 300 meters; my 7.5 is an HD weapon.
Glad you like it, I'm sure it will serve you well in that regard, as long as you don't need to hear or see after the fact.
Do I feel the need to pick a 7.5" AR15 for home defense over other weapons I have? No.