Does an object returned from a method return a non-const reference?

Hello, (java noob warning)

I was reading about generics(works like templates in c++) and decided to write a generic LinkedArray Class (I plan to use this not only for bullets but particles and enemies).

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import java.util.ArrayList;

/**
 * 
 */

/**
 * @author Anya
 *
 */
public class LinkedArray<T>
{

   private ArrayList<T> elements = new ArrayList<T>();
   
   private int size;
   
   private int freeElements = 0;
   private int activeElements = 0;
   
   private int[] freeElementIndex;   
   
   public LinkedArray( int size, T e )
   {
      this.size = size;
      this.activeElements = 0;
      this.freeElements = size;
      this.freeElementIndex = new int[size];
      
      elements.ensureCapacity(size);
      
      for( int i = 0; i < size; i++ )
      {
         elements.add(e);
      }
      
      for( int i = 0; i < size; i++ )
      {
         freeElementIndex[i] = i;
      }
      
   }
   
   public int getSize()
   {
      return size;
   }
   
   public int getActiveElements()
   {
      return activeElements;
   }
   
   public void add( T e )
   {
      
      if( freeElements == 0 )
      {
         return;
      }
      
      freeElements--;
      
      int index = freeElementIndex[freeElements];
      elements.set( index, e );
      
      
      activeElements++;
      
   }
   
   void remove( int index )
   {
      
      freeElementIndex[freeElements] = index;
         freeElements++;
      activeElements--;
         
   }

   public T get( int index )
   {
      return elements.get( index );
   }
   
}

And here's how it is used...

/**
 *
 * @author Richard Eric M. Lope (Relminator)
 * @version 1.00 2013/3/04
 */

import java.awt.Graphics2D;


public class BulletFactory 
{
   
   private LinkedArray<Bullet> bullets;
   
   public BulletFactory( int size )
   {
      
      Bullet b = new Bullet();
      bullets = new LinkedArray<Bullet>( size, b );
         
   }
   
   public int getSize()
   {
      return bullets.getSize();
   }
   
   public int getActiveBullets()
   {
      return bullets.getActiveElements();
   }
   
   public void addBullet( Bullet bullet )
   {
      
      bullets.add( bullet );
   }
   
   void removeBullet( int index )
   {
      bullets.remove( index );
   }
   
   public void updateBullets()
   {
      for( int i = 0; i < bullets.getSize(); i++ )
      {
         Bullet b = bullets.get(i);
         
         if( bullets.get(i).isActive() )
         {
            b.update();
            if( (b.position.x < 0) || (b.position.x > Globals.SCREEN_WIDTH) ||
               (b.position.y < 0) || (b.position.y > Globals.SCREEN_HEIGHT) )
            {
               b.kill() ;
               bullets.remove(i);
            }
         }
      }
      
   }
   
   public void renderBullets( Screen screen, Graphics2D g, ImageAtlas imageAtlas )
   {
      
      for( int i = 0; i < bullets.getSize(); i++ )
      {
         Bullet b = bullets.get(i);
         
         if( b.isActive() )
         {
            int frame = b.getFrame();
            g.drawImage( imageAtlas.getSprite(frame), 
                      (int)b.position.x - imageAtlas.getSprite(frame).getWidth()/2,
                      (int)b.position.y - imageAtlas.getSprite(frame).getHeight()/2,
                      screen );
         }
      }
      
   }
   
}

My questions are:

1. Why does updateBullets() and renderBullets() work? Since I made a local copy of the bullet b from bullets.get(index). Does Bullet b and bullets.get(i) share the same reference and is "deep-copied"?
*Note that I did that code out of curiosity and crossed my fingers it works.

2. Why can't I use normal arrays (vs arrayList ) when doing generic classes?

Thanks!