Ready on the right & TheLastLemming76: Thank you both for your help and the link!
I found my Rifle and it is the LAR-15 Varmint with the 1 in 8" twist.
And if I understand you correctly TheLastLemming76 I might as well go with the 30 rounders and the polymer magazines?
I appreciate all the help very much and will be trying out my ammo as soon as the weather turns "human" around here.
In full disclosure back in the early 1970's I did buy and own two of the "original" Colt AR-15's back when they were in the $400.00+ range - I sold them both for a pittance of profit without ever firing them.
I kind of wish I had them back now.
Thanks again - I better look up some you-tube videos on care and cleaning/maintenance while I have some free (to cold to go outside!) time.
Hold into the wind
VarmintGuy