Sec Form 4 Filing - JEFFRIES DOUGLAS @ GENCORP INC - 2003-12-05

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person JEFFRIES DOUGLAS 2. Issuer Name and Ticker or Trading Symbol GENCORP INC [ GY] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) VP, Controller (Last) (First) (Middle) HIGHWAY 50 & AEROJET ROAD 3. Date of Earliest Transaction (MM/DD/YY) 12/05/2003 (Street) RANCHO CORDOVA, CA95670 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 12/05/2003 D 15,000 D 0 D Common Stock 2,700 I Brokerage Account Common Stock 12/03/2003 J( 2 ) 1,830.923 A 2,862.751 I Plan Trust

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other JEFFRIES DOUGLAS HIGHWAY 50 & AEROJET ROAD RANCHO CORDOVA, CA95670 VP, Controller Signatures Mark A. Whitney as attorney-in-fact for Douglas Jeffries 12/05/2003 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Due to the nature of this transaction, the Price of the Non-Derivative Security is not relevant to transaction. ( 2 )Shares held in the GenCorp Retirement Savings Plan Trust ("Plan Trust") as of December 3, 2003 per the Plan Administrator's records. The number of shares reported is calculated by dividing the dollar value of the participant's account by the closing stock price printed in the New York Stock Exchange Composite Transactions in the Wall Street Journal on the day reported above. This calculation yields only the approximate number of shares in the participant's account because the cash component in the Plan Trust (target 2%) is allocated to each participant's account on a pro rata basis, and the cash component varies based on overall activity of all participants in the Plan Trust.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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