The BRNOs have that rather unsighly pattern pressed into the bottom sufaces of the action that appear to help the action bite a "grip" the stock.
Is it a good idea to file them down before bedding?

In regards to the serrations, don't worry with them... I've never had them cause any problems.

What WILL cause a problem is the little concave cuts (horizontally) on the bottom half of the action... they are on the sides and just behind the recoil lug.

Look closely at yours, and you'll see what I mean. The bottom half of the action is wider than the middle of the action.

When you bed it, you can get it out... but you can't get it back in...

I use a file and sandpaper to narrow the width of the bottom... look closely at yours and you’ll see what I mean. I just did one the other day and wish I had a photo for you, but I don't... sorry.

...I already got rid of those, and cleaned up the rest of the action. Thanks for the heads up though, it would have been easy to overlook.

Cheers.