THIS PAPER DOCUMENT IS BEING SUBMITTED PURSUANT TO
          RULE 901 (d) OF REGULATION S-T


                    UNITED STATES
        SECURITIES AND EXCHANGE COMMISSION
               Washington, DC 20549

                   Schedule 13G

     Under the Securities Exchange Act of 1934
             (Amendment No.    2   )*
          

            Bolt Technology Corporation   
                 (Name of Issuer)

     Common Stock, Par Value $ .00 per share   
          (Title of Class of Securities)

                     097698104        
                  (CUSIP Number)


Check the following box if a fee is being paid
with this statement [].  (A fee is not required
only if the filing person: (1) has a previous
statement on file reporting beneficial ownership
of more than five percent of the class of
securities described in Item 1; and (2) has filed
no amendment subsequent thereto reporting
beneficial ownership of five percent or less of
such class.)
(See Rule 13d-7.)

* The remainder of this cover page shall be filled
out for a reporting person's initial filing on
this form with respect to the subject class of
securities, and for any subsequent amendment
containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this
cover page shall not be deemed to be "filed" for
the purpose of Section 18 of the Securities
Exchange Act of 1934 ("Act") or otherwise subject
to the liabilities of that section of the Act but
shall be subject to all other provisions of the
Act (however, see the Notes).



       (Continued on the following page(s))
               Page 1 of 5 Pages


                                       Page 2 of 5

CUSIP NO.   097698104   

(1)  Names of Reporting Persons S.S. or I.R.S.
     Identification Nos. of Above Persons:

     First Union Corporation  56-0898180

(2)  Check the Appropriate Box if a Member of a
     Group (See Instructions)
     (a)  [ ]
     (b)  [ ]

(3)  SEC Use Only

(4)  Citizenship or Place of Organization:

     North Carolina


Number of Shares Beneficially Owned by Each
Reporting Person with:
(5)  Sole Voting Power           241,400  
(6)  Shared Voting Power               0  
(7)  Sole Dispositive Power            0  
(8)  Shared Dispositive Power    241,400  
      
(9)  Aggregate Amount Beneficially Owned by Each
     Reporting Person

     241,400

(10) Check if the Aggregate Amount in Row 9
     Excludes Certain Shares (See Instructions)

     [ ]

(11) Percent of Class Represented by Amount in
     Row 9

     4.75 % (based on 5,077,000 shares
     outstanding on 12/31/97)

(12) Type of Reporting Person (See Instructions)

     First Union Corporation (HC)


                                       Page 3 of 5
Item 1(a) Name of Issuer:

         Bolt Technology Corporation

Item 1(b) Address of Issuer's Principal Executive
Offices:

         Four Duke Place
         Norwalk, CT  06854
         [X]
     
Item 2(a) Name of Person Filing:

         First Union Corporation

Item 2(b) Address of Principal Business Office:

         One First Union Center
         Charlotte, North Carolina 28288-0137

Item 2(c) Citizenship:

         North Carolina

Item 2(d) Title of Class of Securities:

         Common Stock, Par Value $ .00 per share

Item 2(e) CUSIP Number:

         097698104 

Item 3      If this statement is filed pursuant to
            Rules 13d-1(b), or 13d-2(b), check
            whether the person filing is a:

            (g)[X]Parent Holding Company, in
            accordance with  section 240.13d-1(b)
            (ii) (G)

Item 4      Ownership.

            (a)Amount Beneficially Owned:
            241,400
            (b)Percent of Class:
            4.75%
            Number of shares as to which such person
            has:
            (i)sole power to vote or to direct the
            vote
            241,400
            (ii)shared power to vote or to direct the
            vote
            0
            (iii)sole power to dispose or to direct
            the disposition of
            0
            (iv)shared power to dispose or to direct
            the disposition of
            241,400  




                                       Page 4 of 5

Item 5      Ownership of Five Percent or Less of a
            Class.


Item 6      Ownership of More Than Five Percent on
            Behalf of Another Person.

            Not applicable

Item 7      Identification and Classification of the
            Subsidiary Which Acquired the Security
            Being Reported on by the Parent Holding
            Company.

            First Union Corporation is filing this
            schedule pursuant to Rule 13d-1(b)(ii)(G)
            as indicated under Item
            3(g).  The relevant subsidiary is First
            Union National Bank, Charlotte, NC (BK). 
            The First Union entity listed above
            holds the security reported in a
            fiduciary capacity for its respective
            customers.

Item 8      Identification and Classification of
            Members of the Group.

            Not applicable

Item 9      Notice of Dissolution of Group.

            Not applicable

Item 10     Certification.

            By signing below, I certify that, to the
            best of my knowledge and belief, the
            securities referred to above were
            acquired in the ordinary course of
            business and were not acquired for the
            purpose of and do not have the effect of
            changing or influencing the control of
            the issuer of such securities and were
            not acquired in connection with or as a
            participant in any transaction having
            such purposes or effect.




                                       Page 5 of 5
Signature.

After reasonable inquiry and to the best of my
knowledge and belief, I certify that the
information set forth in this statement is true,
complete and correct.

FIRST UNION CORPORATION 

February 11, 1998  
Date 



                                                   
Signature

Karen F. Knudtsen,  Assistant Vice President &
Compliance Officer