I have a coveted upper with m4 feed ramps, I have a coveted barrel without m4 feed ramps. I would really like to put these two together. Is it possible with a dremel or file carefully and enlarge the feed ramps on this barrel extension to match the profile of the receiver? Anyone ever done this?

I would refrain from using the dremel as it can take too much off with a quickness. As with any filing work take your time and always remember you can take it off but you can't put it back on.

Is the barrel installed on the upper?

What do you mean by coveted upper? If it's just a plain upper, you can sell it or trade it for an upper without M4 ramps.

The barrel is not installed on the upper yet. I am doing a rebuild of a build that I built.

The reason for coveted is that the upper and lower are painted in molyresin with a tiger stripe pattern that would be very difficult to make to match up again if I replaced the upper. Replacing the upper would be my first choice if the two halves were not matched in this way.

Ask if adco could do it.

Get a different barrel.

adco lists the service on their site.    they also point out that they do it with a dremel themselves.

Seriously?

Adco is great, but to pay them to do something ANYONE with two hands and two eyes could do is a little much...

OP there are some manufacturers on this site who still cut feedramps in their uppers by hand. If you do it yourself, it won't matter.

Wouldn't it be CHEAPER to just replace the upper? The rest of my opinion will be in GD...

Easy to do yourself if you have a light touch and patience.(I did it with niether). Adco does it with a dremel and you can too. I had the same problem with my WOA match barrel not matching the M4 cuts on my ARmalite. Took about 20 minutes with a stone and sandpaper roll in the dremel. Just slowly rough cut the barrel with a stone that's close to the size of the m4 cuts. When its close switch to the sandpaper roll and lightly cut it in until you just polish the anodizing off the ramps in the reciever. The trick is to stay off the top of the barrel ramps until you get to the final bit with the sandpaper. You are primarily changing the angle on the barrel ramps, you don't want to cut them deeper into the locking lugs, just line them up with the reciever. Be sure to plug the barrel first and flush everything liberally when you are finished. Metal shavings, stone dust and sandpaper grit = bad for gun actions! Go slow.

Heres pics of my DYI ramps, a little fuzzy thanks to my crappy camera"

so anyone with 2 eyes and 2 hands could go perform brain surgery tomorrow?   sometimes things your not used to doing are better left to those who know what is going on.......If the OP is not used to working on his rifles or comfortable taking on the task, kudos to him for knowing his limits.  Sometimes when you dick around with things you make matters worse....just sayin.

 

Don't hold back, I can take it

You destroyed a good barrel and presumably a good receiver. And for what? Slightly mismatched feed ramps or even the lack thereof will cause fewer problems than home dremel sooper feedramps. Or factory dremel sooper feedramps for that matter.



 

Destroyed? How so? I matched the barrels ramps to the recievers. No metal was removed from the reciever, just the anodizing polished off during the final polishing. The ramps were not cut any deeper into the lugs. No SOOPER M4 ramps made, just a little clean-up and matching to eliminate the over hanging "shelf" created when the non M4 nbarrel was installed into a M4 reciever.
   The rifle has not had a feed failure since this was done, nor any other malfunctions that I can recall. It shoots right around an inch 10 shot groups consistantly, probably better if you were shooting it instead of me. I shot many days of target shooting and an appleseed shoot with it after doing the ramps, a pretty grueling day of shooting for me, zero malfunctions. None of this meets my criteria for "Destroyed", which I usually classify as "no longer functional , of any use , or able to be  salvaged".
   So, explain to me in detail how you arrived at "destroyed" from viewing a single photo from 1000 miles out?

You have modified the receiver (and presumably the barrel extension) in such a way as to render them much more likely to fail in a much shorter period of time. Also, I seriously doubt that your receiver had feed ramps extending to the bottom of the upper. That is a much greater angle than that at which standard M4 ramps are machined.





To answer your question, they cannot be salvaged. You can't get that heat treatment or anodizing back (well, the anodizing could probably be redone at significant expense).





I'm probably more than 1000 miles away and I can see that.





WOA sells barrels with M4 extensions. You probably could have swapped barrels with someone who had a rifle receiver. I know I build the occasional upper that doesn't have M4 ramps. I've swapped otherwise identical, brand new barrels and receivers with people before.

 

Hmm, After you pointed it out I did some research and you are right , I DID go too deep on the receiver angle wise. But the rifle functions well and I'm happy with it, so I will await the predicted failure, along with the predicted failure of my FCG from another thread. My Rifle is predicted to be full of fail, I'm sure there will be celebrations across the land when it finally lets go. Hopefully I will live through the event to report it here.

I wish you and yours a long service life.