Robert, the only scope mount I have seen that will stay tight on a Savage 24 with 20 gauge recoil, is a set of see thru aluminum rings, made by Ncstar, part #RB19. I was told of these rings, by EE, of the Savage 24 Discussion board, and we can both attest to the fact that it doesn't work loose under 20 gauge recoil. However, you need to file them a bit to fit properly, you need a rat tail file to file the underside of the ring base, because of the 'hump' the 24 barrel has between the dovetail grooves. Sometimes, you need to file the right side of the ring base to make sure it tightens enough. Not a big deal, and if you take the time to do it right, it will not shoot loose. Anything you file, you can just cover up with permanent black magic marker, works real good. here is a web addy where you can purchase these rings:
http://www.ammo-master.com/specials3.htmlAnother thing you need to understand, is that the Savage 24J-DL has extrememly small iron sights, and while these are see thru rings the iron sight sit so low, they cannot me seen thru the see thru part, so if your intention is to use scope and iron sights, you are out of luck on a 24J-DL, any of the other 24's, with standard size sights, will allow you to use both.
Hope this helps.
Sincerely,
Garry