Not having M4 ramps can be problematic in SOME rifles. From what I hear, it can be more problematic in 6.8 builds, and that’s what this is.
We could debate the need for Milspec M4 ramps like Colt offers all day long, but I definitely prefer them on all my rifles.
Thanks anyhow.
Dremel makes some small diameter stones for shapening chain saw blades.
These do not have any taper and are about 1-inch long. I do not use them in the dremel electric grinder as they can easily remove too much material “off-center.”
So I use them like a file mounted in a little handle with a little honing oil on the stones.
Being careful this way by hand, you can better control removing just enough metal to give you a smooth transition by following the master angle already present in the barrel extension.
I then take a felt bob to a belt sander and twill it against the belt until its a nice tight small diameter taper that fits the feed ramp well. Then I enbed this with Smicrhome Polish (see Brownells) and use this with the Dremel to polish.
I basically do what Coldblue does but I do use the Dremel. I just take my time.
Here’s a thread dealing with one I fixed for a member of this site. https://www.m4carbine.net/showthread.php?t=9542&highlight=ramps
I used a rat tail file and go slow. I had to do this to shoot the flat tip ammo. It was haning up on the Stag upper( lefty )I used for my build. Works good now with all ammo.