I just completed a build to realize that I have a rifle extension on a M4 feed ramp upper. There is a significant ledge from the extension over the receiver feed ramps. I have not fired the rifle and do not want to have to buy another upper receiver due to my ordering mistake. Am I able to fire the rifle like this without causing damage, am I able to do an semi-permanent solution like filling in the wedge cut out with JB weld or some other type of solder or epoxy? This is an plinker/ varmint rifle only.

http://i1069.photobucket.com/albums/u479/Rondizzy1/IMG_0383.jpg
http://i1069.photobucket.com/albums/u479/Rondizzy1/IMG_0385.jpg

Send it in to adco and fix it right.  Might cost you a couple Jacksons depending on shipping and shop charges. At least you'll know it's right

palmetto has non feed ramp uppers cheap http://palmettostatearmory.com/index.php/featured/m16-a4-stripped-upper-receiver.html

Some have dremeled the ramps on the barrel extension themselves.

You will most likely end up with feed issues on every round. You can send it to ADCO but even they state on their description of fixing this problem that you can do it yourself. If I wasn't going to get the proper parts and end up with two uppers, I would just get a rat tail file of the proper size (or dremmel) and have at it. Carefully, of course

I guess another upper receiver is in order. I was hoping a little filler would work as an short term solution. I doubt the boss wants to hear that.

A small jewelers round file and 10 minutes of careful hand work and it's fixed.

Thank you guys for all your advice. I believe I have it SPF's right now on EE. I can recoup my money and get the right part without upsetting the Boss.