There was some discussion on here last week regarding the original composition returning to some 2009 cents so I quote. March 3rd 2009 Numismatic News page 48, "Numismatic versions of the four commemorative cents will have exactly the same metallic content as the 1909 coin (95% copper 5% tin and zinc). These collector coins will be minted in proof and uncirculated condition and be included in Mint collectors products". So we will see.
Yes, the 95% copper composition cents, as used in Indian Head cents and Lincolns until 1983, will be available with all four of the new reverses in special collector sets available directly from the US Mint.
Plus the proof also other composition changes happened. To be technical all eight (P&D) plus the proof adding four more for 2009. Also the composition chaged in 1943 (steel) then to Shell Cased Bronze (1944 to 1946) then back to French Bronze (1947) then in 1962 to Brass and finally 1982 both Brass and the new Copper Plated Zinc. ***Source The Authoritive Reference on Lincoln Cents, pg. 304 " by Wexler/Flynn***
