Which one is probably better for urban tactical use?  The reason for the 55 grain is that one of my favorite ARs has a 1 in 12 twist.  These two loads are readily available over the counter in my area and yes m193 ball would still be my primary load.  I just want some opinions for an alternative load that will expand under less than ideal circumstances(not totally dependant on high velocity).

Quoted: Which one is probably better for urban tactical use?  The reason for the 55 grain is that one of my favorite ARs has a 1 in 12 twist.  These two loads are readily available over the counter in my area and yes m193 ball would still be my primary load.  I just want some opinions for an alternative load that will expand under less than ideal circumstances(not totally dependant on high velocity).

Neither of the above! Go to www.georgiaprecision.com and buy some of their 50 round boxes of 75 gr BTHP's. If your rifle's twist is questionable, might wanna check out the 68 or 69 gr BTHP Match loads they have. If you have an SP1 or something else with a 1/12 twist, then stick with M193. You mention urban situations in your post, so keep in mind that even from a 16" barrel, the M193 will likely maintain the necessary velocity to fragment at any distances you are likely to be shooting in built-up areas. And oh yeah, go read the FAQ tacked on at the top of this forum. It will likely help you with this and every other ammo question you ever had for the 5.56mm ammo!

READ THE AMMO FAQ.

It will tell you the bal tip is an underpenetrator for your application.

TXLEWIS