64 gr Win Power points are designed for game like deer, they are a good bullet provided shot placement is good.
Your grouping of 3" at 100 yards is good for deer. If you shooting at that distance you will have time to place your shot.
IF the "Q" fragmented and you did not shoot into the onside shoulder, probably no meat wasted, but my guess is that the whole deer will be wasted, because the wound will be insufficient to incapicate the deer quick enough for you to recover it.
IF you shot into the shoulder, it would probably put a nasty wound on the deer and same result as above.
Sorry if I sound like a broken record, but please stay away from the FMJ ammo. Go with the Power Point or get some X bullets, PMC may load them in 223. They will expand reliably, and penetrate and be your best bet.