If you are still using the Echo1 SG Series (MP5 replicas) you can get a bag of bbs or a high cap magazine just by following their simple instruction... "Operation: Phoenix Project  Just send us your Echo1USA SG Barcode, warranty card, and copy of the receipt and we’ll send you an Echo1 SG Hi-Cap Magazine or an Echo1USA Bag of 5000 BBs free! This offer ends December 31, 2010."

So better find those barcodes/warranty card/receipt so you can get a freebie from them.