Really, could have skipped this; the only thing that would occasionally hang up was some handloads with flat-nosed bullets; and only when they were the top round in the mag and you were chambering them; when firing they never missed a beat.
However, there were some small tooling marks on the ramp, so decided to smooth those out a bit. So strip the frame, pad the vise jaws and set it at the appropriate angle so the ramp- indicated by arrow- is level. Using JUST enough pressure to hold it steady.
Blacken the ramp, and lightly work the abrasive, checking frequently to make sure you're centered and level. Every time the black was gone, I'd mark it again.
Do this ONLY until the necessary amount of polishing is done; if you do this on one with deep tooling marks(no matter the make/caliber/whatever), ONLY polish the high points where the cartridge will actually contact; if you try to remove all the marks, you may cut deeply enough to screw with feeding. I only had some light marks, so it took very little to make them go away*.
Do NOT chuck something in the dremel and start cutting.
Unless you're a pro on things like this I'd say do NOT use any powered equipment at all.
POLISH is the key: make the surface nice and smooth, don't remove a lot of material.
If you absolutely have to use a dremel, ONLY use a felt polishing wheel and buffing compound to clean up the surface. And use a very damned light touch. Screw up the angle of the ramp, or cut too deep, and you're screwed. The only fixes I know for that are a new frame, or having someone mill out the ramp area and solder in a replacement ramp insert.
Oh, wait; you may be truly screwed, I just checked Brownell's and they show that insert discontinued. So DON'T SCREW IT UP.
One more thing: if it's an aluminum frame, DO NOT POLISH THE RAMP. AT ALL. Aluminum is soft, and the hard anodizing on the frame is hard. If you cut the anodizing off the ramp, every time a bullet bumps into it, it'll dent and/or wear. The ramp won't last long.
Just to get one more whack on this horse, take a look at this page on The High Road; frames screwed-up by unneeded and/or too-much 'polishing'. To borrow,
Although it's apparent that most of the "work" was done with a grinding
wheel, and followed with a buffing wheel, I've seen the same damage done
with a buffing wheel and jeweler's rouge alone. It just takes longer
to destroy the ramp.
*Very happily. I have a horror of the thought of cutting too deeply.