If your just trying to get around the real problem go ahead with pads, etc. The real problem lies in excessive bolt speed and or excessive ejector spring tension. Hot loads can also cause high bolt speeds. A stronger buffer spring like the Tubb CS, will slow the bolt down. If you go this road, make sure you get the right spring for your particular AR-15 type and gas system.
Shortening the ejector spring will keep the case body from slapping the locking lugs hard and limit the spin on the case as it goes through the ejection port to strike the deflector. This modification can keep your AR from tossing your brass 15 feet from your rifle at the same time. Check the link below.http://www.gswagner.com/arejector/arejector.html
I have done these modifications, and the empty cases look like they came from a bolt action rifle rather than an AR-15. That is, no dents, dings or overly powder blackened cases.