Well just bought 2 R1A1's from two differant people at Kenton Nationals in Ohio.
Both are in great shape and identical,  paid $400 for one and $375 for the other.
I made a mistake though and let my excitment rule my judgement and did not fully inspect
the $375 one , after getting home and  cleaning them I went to the range.
First one shot great but I don't like that muzzel brake, the second one I fired one round (ok)
the second round fired and "BOOM" I droped the rifle (laying prone) left hand stinging like
hell(was near magazine) checking for injuries  none thank God had glasses on , said prayer and ckecked rifle. Magazine was bulged out floorplate spring and follower stuck in the ground an inch
remianing rounds piled  on ground one was bent. Checked rifle and the case was stuck in the chamber held charging handle and banged but on the ground and round poped out , rear of case ruptured and thats when I looked at the throut someone had taken a grinder to the ramp and ground off so much metal that they got into the barrel and removed enough metal that there was no
support for the rear of the case. Thats way it blew out.
The barrel and reciver are trash (althought I think the reciver can be welded up again)

I will never again forget to check out the chamber again on a used firearm.

Good news is I've got spare parts

glad you're alright!!
yeah, you still probably get your $s worth out of the parts kit &compliance stuff.

man, i think about these kind of things everytime i see people shoot with their hand under the mag...
gotta check headspace on anything homebrewed or beaver-built.
again, glad you're alright

Man, you could have been killed!

I would have never guessed someone could/would do something like that.
I hope you are going to be looking for the guy that sold it to you.