I ordered this hood from Numrich and it arrived.

Part is as described and will work fine with a little fitting required. The slot in the hood needs to be widened from .180" to .250" to fit on the sight. That's no problem.

But I think there should be some means of securing the hood so it doesn't get knocked off and lost (recoil shouldn't be much of an issue - it's on a 6.5 x 55...).

The grooves in the ramp are smooth, with no notch or anything. The hood, incidentally, has a very shallow notch on each side of the slot, midway down.

What do you guys recommend? Loctite? A set screw? Or...?

Why didn't you simply order a Williams hood for $5.99?

They're both Williams hoods. The onlyiest difference is that the one I ordered has the authentic (for my aftermarket model) checkerd band around the front. It's a couple bucks more for that.

Pics/dimensions are otherwise identical.

I have bought several of the williams over the last two years and they all had the band. Fit the ramp perfectly.

Williams ramps have never had any sort of hood retainer other than friction. This has always been a sore point with me and so I never use them.

One fairly simple solution would be to drill a small(tiny) hole through the side of the ramp's male hood groove and then insert a short tight-fitting pin, leaving just enough of the rounded pin end protruding to serve as a detent for a matching notch in the hood's female groove. This is the method used by Redfield and Burris for their hood retention. It ain't perfect but it works fairly well.
Regards, Joe

Thanks Joe. I might use a pin, but I'm kinda leaning towards a set screw. We'll see...

Art, This ramp is old (I guess, from the box) and is .340" wide, not .250" like the newer ones!

The grooves are .045" deep, resulting in the slot needing to be .250".

Hoods were never intended to be used in place. They are there for protecting the front sight only and are to be removed before you shoot.
Now if you want it to stay on but be able to remove it with little effort then machine the grove slightly undersize and with a bit of a tapper so it wedges itself in place

Should I tell my BPCR friends...?

My ramp is the screw-on type. Perhaps that accounts for the extra width?