600W HPS Without Reflector

Hey guys. Just got my grow tent and Sun System 600W HPS light in today. I was misled by the photo on the website and assumed the reflector came with the light.. Now I see that to buy one is going to cost over a hundred bucks.
My question, is it safe/efficient enough to run this lamp without the reflector until I can scrape up enough cash to purchase one? I'll be using a 2'7" x 2'7" x 5'11" grow tent.

Thanks

i think your big problem is gonna be getting rid of the heat but as far as the light i say use it till u get your sheild