Transact SQL :: Table Locking Happening When Removing Huge Data

declare @error int, @rowcount int
select @rowcount = COUNT(1) FROM  STG_BCDR;
while @rowcount > 0
begin
 BEGIN TRAN Deletion

[code]....

Above code i try to delete records batch by batch to avoid table locking at BCDR table.total records in this BCDR  table is 40,000 records.  However I run the code at execution plan, the BCDR table still clustered index scan which means that the locking still happend.

If i change the delete top (5000)...... to delete top (5).... then thre is clustered index seek, which is good..The problem here is  each time  only delete top 5 records which is means it will realy take very long time to remove those  data.

how to cater the situation inorder for me to delete those huge data without table locking happend. If table locking happend , then other user will not be able to access this table at the same time.