1/8. Absolutely, Positively, don't have a clue. just didn't want ya hangin out there, without any responses. I'd try the website..........So I did, and they don't have anything, on the 223. ??? that's stupid.
It is easy to do the cleaning rod trick.You put a slotted tip on and use a tight fitting patch. Hopefully you have a dewey rod with the ball bearing handle. Push the rod in most of the way,now reverse the direction by pulling it out about an inch or so.Now put a mark on the rod or tape right at the crown of the barrel. Now pull slowly and watch the mark as you are pulling ,till it makes 1 full revolution,then stop. Measure from the barrel end(crown) to the edge of the mark or tape and it will tell you exactly what the twist measures.I would bet it is 1-12 twist like most remmys except the LTR.