There was a long debate on forged receivers on this thread. In the end, the main critic of cast receivers did additional research and concluded that the sources of the negative information he heard were unsupportable.
http://www.thehighroad.org/showthread.php?t=20673&highlight=forged+receivers
The years when the M1a ruled the Across the Course firing line is over. It faded quickly starting about 1994. Around 1995 about half the service rifles on the firing line were M1a, by 1998 you might see one every twenty fire points.
During the period, 70’s through 90’s, if you were a civilian and wanted to shoot service rifle you either had a State Association M14 or you bought a Springfield Armory rifle.
The only common failure mechanism to GI receivers and aftermarket was cracking in the sidewalls. The bolt rebounds off the back of the receiver heel and the sides, given enough impacts, a receiver would crack along the sidewalls behind and underneath the rear sight.
In 1996, USMC shooter Julie Watson was working on winning NRA Highpower week, after having won CMP Service Rifle Week at Camp Perry when her M14 receiver cracked, and her M14 started flinging shots at 600 yards.
Springfield Armory added material to the sidewalls of their receivers making them more resistance to impact cracking and a bit stiffer. GI receivers, and close copies of GI receivers, and that includes the LRB receivers, have a thinner sidewall.
I purchased a M1a which for the first owner the receiver cracked. Springfield Armory replaced the receiver for free. I have a shooting bud whose SA receiver developed a crack above the bolt release, SA replaced that for free. The second rifle was on its sixth barrel, which is about $15,000 in ammo shot through it, so I think the customer service from SA is excellent.
I have examined LRB receivers, they are very well made. LRB receivers are made from 8620 steel which was the steel used by the military.
8620 is a decent steel, but I have asked SA and Lou why they did not make their receivers from a higher grade of steel, such as 4140. Basically it is because of the people who think “mil spec” is perfect and the negative comments they would get from such fanatics.
Incidentally the Chinese made their receivers from a 5100 series steel. Mil Spec fanatics foam at the mouth about this, but if you look up the use of 5100 steel in Machinery Handbook, that steel is used in much tougher appications than 8620.
Springfield Armory receiver showing thick sidewall
LRB double lugged receiver.