I bought several 30 round steel mags from Ammoman.com advertised as Royal Ordnance SA-80 mags.  The mags arrived today and look to be quality but there are no markings on the mags.  Is this normal?

yes

repub18, thanks.

I have read other posts stating the SA-80 mags were stamped "England".  How do I tell if they are Royal Ordnance?

Hey, if they work who cares, right?

I got some that had marked floorplates, some with those ENGLAND stickers on them, and some with nothing on them.  No markings = legal and alright to own.

Get to the range and test them all out as much as possible!

Quoted: repub18, thanks. I have read other posts stating the SA-80 mags were stamped "England".  How do I tell if they are Royal Ordnance?

The british mags have "England" on the inside of the follower.  Grey "Royal Ordinance" mags have no other markings (beyond the sticker).  Black "Imperial Defense Services" Mags are stamped on the floorplate.

I have both.  The Royal Ordinance mags have run very well for me.  But I made upgrades to my Imperial Defense Services Mags as they use old style followers.  Their springs aren't as thick as the Royal Ordinance mags either.

Just make sure the Royal Ordinance mags all lock into your AR.  I had to break in one of mine at the range before it would reliably lock.