I've never done this but it needs to be done on my RSM .458Lott which is jamming when feeding flat nosed rounds. I don't want to mess it up as I leave for Zim in 6 weeks. What is the best way to accomplish this? Thanks in advance for your advice.

Would have to assume since the rifle is Ruger RSM in 458Lott you will be after some potent form of game and would highly suggest having a 'smith with skills in the area you are talking about do the work. Your rifle is no longer in production and somewhat scarce compared to others and removing metal is far easier than replacing. Dremels are a wonderous tool, but many a gun has been damaged by their use as well. Just a suggestion and good luck on your hunt.

Hi,

I have used a Dremel with one of their expanding sanding drums over which one places the appropriate grit sleeve. The 3/8" size using fine grit works well.
Go slowly and gently using Prussian Blue or a Magic Marker to indicate rubbing spots. After the Dremel, lengthwise hand polishing of the ramp with 400-600 grit emery cloth helps keep things going in the right direction.

Before altering the ramp I suggest experimenting with seating your bullets a bit deeper. Often only a few thousandths will allow consistent, smooth feeding. Round nose DG bullets are highly rated for a reason, but you already know that.

Good luck with this, your hunt and trip,

Stephen

Click here...MX Wheel is what you need

You will need to turn it faster than a Dremel so buy a cheap 1/8" air grinder

1/8" Air Grinder