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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 NLvJo9WP32KJ64VaEo0s+i8QhyhuDjngobpMc3oFFDjMRW90kSHs7ONa2B7cIB5j
 XNXI3SSnNlaPJRgokQ6xYw==

<SEC-DOCUMENT>0001104659-04-022360.txt : 20040804
<SEC-HEADER>0001104659-04-022360.hdr.sgml : 20040804
<ACCEPTANCE-DATETIME>20040804182236
ACCESSION NUMBER:		0001104659-04-022360
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040803
FILED AS OF DATE:		20040804

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			GUSS JONATHAN G
		CENTRAL INDEX KEY:			0001186655

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10582
		FILM NUMBER:		04952766

	BUSINESS ADDRESS:	
		STREET 1:		713 CLOVE LANE
		CITY:			FRANKLIN LAKES
		STATE:			NJ
		ZIP:			07417

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ALLIANT TECHSYSTEMS INC
		CENTRAL INDEX KEY:			0000866121
		STANDARD INDUSTRIAL CLASSIFICATION:	GUIDED MISSILES & SPACE VEHICLES & PARTS [3760]
		IRS NUMBER:				411672694
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0331

	BUSINESS ADDRESS:	
		STREET 1:		5050 LINCOLN DRIVE
		CITY:			EDINA
		STATE:			MN
		ZIP:			55436-1097
		BUSINESS PHONE:		9523513000

	MAIL ADDRESS:	
		STREET 1:		5050 LINCOLN DRIVE
		CITY:			EDINA
		STATE:			MN
		ZIP:			55436-1097
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-08-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000866121</issuerCik>
        <issuerName>ALLIANT TECHSYSTEMS INC</issuerName>
        <issuerTradingSymbol>ATK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001186655</rptOwnerCik>
            <rptOwnerName>GUSS JONATHAN G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ALLIANT TECHSYSTEMS</rptOwnerStreet1>
            <rptOwnerStreet2>5050 LINCOLN DRIVE</rptOwnerStreet2>
            <rptOwnerCity>EDINA</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55436-1097</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-08-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>876</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>62.80</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18184</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The amount reported includes 17,509 shares subject to certain restrictions (including possible forfeiture) applicable to restricted stock grants under the Issuer's Non-Employee Director Restricted Stock Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jonathan G. Guss</signatureName>
        <signatureDate>2004-08-04</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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