Thanks, the SAI reciever has the standard SAI barrel. I bought the SAI on a whim, shot a few rounds with open sights then put it away. I then came across a Fulton stripped new lower so I sent it off to Fulton with the SA GI barrel but they could not headspace it because their early recievers were not designed for chrome lined barrels. I had an 18 inch criterion bbl installed with all other parts GI on the Fulton reciever. Then scoped the SAI and found that it was a good shooter without any mods and began taking interest in building a more accurate rifle if possible so I bought the Polytech, stripped it and acquired all GI parts to put together with the GI barrel. that stalled out and I started researching what I could get accuracy wise with other barrels. So I definitely want to build a match grade barrel type gun. Still learning and researching. The SA GI barrel has been waiting 30 years for me to find it a mate but now with the hankering for accuracy and not just a standard M1A, I am weighing options. Another possibility is to sell the GI barrel or buy another reciever and finish that project after the Krieger project. I am spending a lot of time reading on this board and wanted input. So all that said, ideally I want a 1 inch or less 5 shot group out of my gun, whatever that may be. Now I also think I want a SOCOM for range fun not serious shooting. I have generally been in heavy with Full Auto stuff and not paid much attention to the accuracy end of the equation but I am really enjoying these rifles.