It sounds like they rushed them into the trials. I'm sorry to hear that they really did have problems.
The AR-10's right now do have a problem with jamming but that's because of the magazines. Sending in a brand new, in the wrapper M-14 mag, then paying an embarrassing ammount of money to have it reworked and finding out it doesn't work can be trying. My son's AR-10 is flawless except for one or two magazines that he still has to tweak.
I have a picture of an M-14 that blew up because of a crystalized barrel.
"... The AR-10's right now do have a problem with jamming but that's because of the magazines. Sending in a brand new, in the wrapper M-14 mag, then paying an embarrassing ammount of money to have it reworked and finding out it doesn't work can be trying." That's too bad. There's a scarce amount of M-14 magazines left, and no shortage of Springfield M-1As coming off the assembly line.
Too bad that Armalite didn't -- or doesn't -- make a version that uses FN-FAL mags.
M-14 mags: $60/each, and climbing.
FN-FAL mags: $4/each, and stagnating.
Converting an M-14 mag for AR-10 service is a risky and expensive gamble.