Early gen 1s didn't come with the end of the bolt chamfered, which caused alot of feeding and ejection failures. There are posts online on how to disassemble the bolt to check. But your serial # is fairly high so I'd guess your bolt is already chamfered. If it isn't there were posts on how to DIY with a file.
My gen 1 had the same issues as you, and changing to a much heavier 6oz buffer cured it instantly. I saw 2-3 failures per mag over the first 100 rounds, and was in the CSC indoor range at the time. Walked into their store, bought a heavy buffer, changed it right there in the range and put 200 more rounds downrange without another failure. IMO it's well worth trying if you're jamming constantly.
Some guys have added 3-6 quarters into the end of the buffer tube to reduce stroke, with mixed results. I put a longer 308 rifle spring in mine, after swapping buffer weights. It didn't hurt anything but I'm not sure if it did anything to help.
You may also see improvement by polishing the feed ramps as well.
Hope that helps