Will it fragment properly?

I think the answer is "maybe," or "sometimes."
There was a police shooting in Scottsdale a few years ago.  BG in a chase bails out and runs into a Safeway store.  Grabs a geezer for a hostage and heads out the back door.  Just outside the back door is SWAT guy, waiting for him, with 10.5" AR, TAP 75.  He fires twice, one to the chest, one to the head.  The head shot exploded the BG's head like Gunny shooting a watermelon; completely shredded the head.  The chest shot penetrated and hit the geezer (who was being pulled along behind the BG, and seriously injured him.  Geezer nearly died, but miraculously survived surgery.
But, that's just one incident.

This is relevant to my interests

I don't think I can shoot TAP through my penis.

Slacker.

I think you mean to be in the survival forum.  They do a lot of talk about rice over there.

This is why I went with 6.8 for my 7.5 ar pistol

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75 gr TAP:

So restricted 5.56 TAP should work.

But the Commercial .223 TAP, wouldn't be reliable?

2250fps is considered minimum.  Chrony it and see–– every barrel is different.  Best case, you'd be cutting it really close.





 

So you are assuming that TAP fragments the same as M193?

Edit:  I just looked at a TAP FPD round.  I see no cannular, but did see a hollow point on the end.  The fragmentation mechanisms will be completely different from M193.

No, the hollow point is simply a byproduct of manufacturing.



TAP fragmentation is similar to M193––the bullet yaws then fragments when the jacket cannot withstand the force on the side of the bullet.



 

Take a look here about 3/4 of the way down.  They discuss TAP and compare it to M193.

http://ammo.ar15.com/project/Self_Defense_Ammo_FAQ/index.htm

TAP is much more effective.

How about Hornady's 55 gr .223 TAP? Everything I can find on TAP ballistics is always about the heavy stuff.  How does the 55 gr TAP do from a 10.5"?

Yes, TAP is much more effective then M193, but it fragments for the same reason M193 fragments. However, TAP's open tip that you referenced in your previous post has nothing to do with it.

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Quote from that link:

conclusions:
These rounds (Hornady 75 and Nosler 77) will fragment at MUCH lower velocities than standard M193 or M855 ammunition will, making them suitable for shorter barreled rifles, or for longer distance shots. Both faired very well, and are just about equals to each other, and definitely outperformed our previous M193 experiments and the M855 data that we've seen. However, we both think that the 77gr Nosler has a larger temporary wound cavity than the 75gr Hornady. However, this could have been due to the slightly increased velocity. However, given that the Nosler *slightly* outperformed the Hornady, we would choose the Hornady over the Nosler due to the possible setback issues inherent in non-cannelured rounds.

I'm not sure what you're arguing (edit) the argument is about.  It says "shorter" not "10.5" with .223 pressure loadings."  M193 fragments above 2700 fps, I stated 2250 was the threshold for the Hornady 75gr bullet–– that's a big difference.  The fragmentation mechanisms (yaw -> stress -> frag) between Hornady 75gr and the 55gr M193 bullet are the same, however, and they both have cannelures.  The hollow cavity in the 75gr, along with the increased length, does serve to move the balance of the bullet rearward leading to much earlier and more reliable yaw following impact than the M193, and the length also puts more stress on the cannelure during sideways travel through tissue further hastening and magnifying fragmentation.  I should probably point out that a cannelure is not necessary for fragmentation, but (other things equal) it does weaken the jacket lowering the fragmentation threshold.