Joining of two tables, one containing a large amount of data. Need help optimising the query

I have been given a job of taking two tables (trimmed down create scripts below) and merging their data into a third table.

` 
CREATE TABLE dbo.Ztest_nominal
(
  BMCode       varchar(20)     NOT NULL,
  nomcode      varchar(500)    NOT NULL,
  Description  nvarchar(4000)  NULL,
  LanguageID   int             NOT NULL,
  CONSTRAINT PK_Ztest_nominal PRIMARY KEY CLUSTERED (BMCode ASC)
)

CREATE TABLE dbo.Ztest_Participation
(
  ParticipationID       int IDENTITY(1,1)  NOT NULL,
  BMCode                varchar(20)        NOT NULL,
  LatestVersionNo       varchar(5)         NOT NULL,
  LastVersionSubmitted  varchar(5)         NOT NULL,
  CONSTRAINT PK_Ztest_Participation PRIMARY KEY CLUSTERED (BMCode ASC)
)

` The third tables columns to take the contents of above (basically the above two tables):

`
[ParticipationID] [int] IDENTITY(1,1) NOT NULL,
[BMCode] [varchar](20) NOT NULL,
[LatestVersionNo] [varchar](5) NOT NULL,
[LastVersionSubmitted] [varchar](5) NOT NULL,
[nomcode] [varchar](500) NOT NULL,
[Description] [nvarchar](4000) NULL,
[LanguageID] [int] NOT NULL

` Ztest_nominal has about 63,000,000 rows and Ztest_Participation about 62,000 The sql I was going to use (with an insert into) is (I did have the inner select outside before I gave up and posted here!):

`
SELECT 
  p.ParticipationId,
  p.LatestVersionNo,
  n.*
FROM
  Ztest_nominal n
INNER JOIN
  (
    SELECT 
      ParticipationId,
      LatestVersionNo,
      BMCode
    FROM 
      Ztest_participation
    WHERE 
      LatestVersionNo = LastVersionSubmitted
  ) p 
    ON p.BMCode = n.BMCode

` However i feel its going need some optimisation so its not slow, also I've already had out of memory errors when running it. Any help would be appreciated