What readibly available 55 FMJ bullet for reloading is most similar to the XM193 bullet? I'm looking for a bullet with similar terminal ballistics.  

I'm not planning on shooting reloads in the near future as it's just not cost effective for me to do so.  But, should the SHTF and I run out, loose my ammo stache, etc, I'd like to have a supply on hand to load.

Big Al

Just get the IMI 55 gr. FMJBT from wideners.com

I was wondering about that too, more specifically about winchester 55gr fmjbt  that they  sell for reloading in .223, because Cabela's has them and I was going to get some but then I started to wonder if they have the exact specifications the m193 bullets Whinchester uses in their q3131a loads has. I'm going too keep the muzzel velocity in my reloads the same as what my q3131a ammo does, hoping that the bullets will fragment like the q3131a bullets do.

The cantalure on IMI and WIN 55 gr FMJBT is in slightly different positions.  

I can't remember which one was further back on the bullet, however.

I think with the IMI that the cantalure is below the caseneck when the bullet gets seated.  With WIN I can still see some of the cantalure when I crimp.  Of course this is with untrimmed once fired brass that just barely meets the OAL spec.