-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 DlRD/XD14PIqXGXA8hgtd3yki53L9pFkWY+7ABWRQ6vQ7BkCi2SKo5F+hxvpnCuu
 qOtUUGJ+8hwqKaNSTZmGWA==

<SEC-DOCUMENT>0001104659-04-014966.txt : 20040518
<SEC-HEADER>0001104659-04-014966.hdr.sgml : 20040518
<ACCEPTANCE-DATETIME>20040518111306
ACCESSION NUMBER:		0001104659-04-014966
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040514
FILED AS OF DATE:		20040518

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MURPHY DANIEL J
		CENTRAL INDEX KEY:			0001067996

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10582
		FILM NUMBER:		04815070

	BUSINESS ADDRESS:	
		STREET 1:		C/O UNIFIED WESTERN GROCERS
		STREET 2:		PO BOX 513396
		CITY:			LOS ANGELS
		STATE:			CA
		ZIP:			90051

	MAIL ADDRESS:	
		STREET 1:		UNIFIED WESTERN GROCERS
		STREET 2:		PO BOX 513396
		CITY:			LOSANGELES
		STATE:			CA
		ZIP:			90051

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>2004-05-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001067996</rptOwnerCik>
            <rptOwnerName>MURPHY DANIEL J</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>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-05-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>11</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>58.58</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3886</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>333</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-05-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6028</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>53.51</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6028</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>22066</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares withheld to pay taxes applicable to the vesting of restricted stock.</footnote>
        <footnote id="F2">The amount reported includes 535 directly owned shares held in the Issuer's Stock Purchase Plan as of March 31, 2004.</footnote>
        <footnote id="F3">1-for-1.</footnote>
        <footnote id="F4">The Phantom Stock Units were credited to the reporting person's account in the Issuer's Nonqualified Deferred Compensation Plan (NQDCP).</footnote>
        <footnote id="F5">The Phantom Stock Units are payable in cash following the reporting person's termination of employment or such other date specified by the reporting person.  However, the reporting person may elect to transfer funds into other investment accounts within the NQDCP from time to time.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/Daniel J. Murphy, Jr.</signatureName>
        <signatureDate>2004-05-14</signatureDate>
    </ownerSignature>
</ownershipDocument>

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