Since I am new to M1A, here's a newbee ?
Why don't SA M1As have rear lugged receivers?  Seems like the rear lugged gives the receiver more beef to withstand recoil, or  the rear lugged not neccessary, and it's just extra insurance & over engineering design.

ETA: Was there ever a receiver w/o rear lugged that broke at the lugs due to recoil, or battering over time?

Sure my new M1A EBR is covered by SA lifetime warranty, just trying to learn is all  

tag

They do make one as well as a double lugged one I believe.  They are usually on the full blown match rifles that have the glass bedded actions within the stock.  It is more for the bedding of the stock.  More surface area will enable better/longer lasting bedding job.

Quoted: They do make one as well as a double lugged one I believe.  They are usually on the full blown match rifles that have the glass bedded actions within the stock.  It is more for the bedding of the stock.  More surface area will enable better/longer lasting bedding job.

Interesting, if the rear lugged was designed for extra bedding surface and not recoil reinforcement, then I have no worries, cause my EBR chassis just gave mine instant tight bedding.

Quoted: They do make one as well as a double lugged one I believe.  They are usually on the full blown match rifles that have the glass bedded actions within the stock.  It is more for the bedding of the stock.  More surface area will enable better/longer lasting bedding job.

+1.

For your every day plinker or casual shooter it is overkill IMHO.

Springfield makes a single lug receiver.  The lugshelp the glass bedding and also help get the gun back on zero without having to reseat the receiver into the bedding after removal.  You still don't want to remove the receiver more than once a year as it breaks down the beddign more quickly.