Re: Need to fix sharp/narrow AR15 feed ramps
I recently built my first AR and had the exact same issue. The bullet tips were handing on a ridge created between the upper receiver feed ramps and the barrel extension's feedramps. It doesn't take much to get a FTF when there is an edge that slows the inertia of the BCG.
Before photo:
The Process -
The best way to get this corrected (sharp barrel extension edges) is to pull the barrel from the upper receiver which will give you free range of motion to get the grinding and polishing done.
Alternatively you can leave the barrel in the receiver and with a sure hand and the dremel bit at full length you can slowly work the area.
I used Dremel P/N: 453 which is a chain saw sharpening stone (blue in color). You want to be sure that you dont get overzealous and make new angles and sharp edges, rather you're feathering or blending the edge you circled in your photo to take away the sharp point.
After you have taken that edge off, you will put on a buffing bit and use Dremel polishing compound P/N 421, it is mildly abrasive so don't stay on the surface area too long. Work it until you can discern that it is polishing the surface area.
Then buff with a fresh buffing bit. Almost done here.
Lastly find some Flitz polish and with a qtip apply it to the area and rub rub rub. Then fresh buff bit and buff buff buff. Now you should start to see a bit of shimmer.
After result:
FINAL NOTE:
If you leave the barrel in the upper receiver and do the above process, cover your chamber and taped it off. The polishing compound will settle in your chamber if you don't do this which will then result in you having to scrub and rub that out.
Goodluck,
BB
