Aliens: Steel Egg

From Xenopedia

Aliens: Steel Egg is a fictional novel in the Aliens universe written by the Bram Stoker Award-winning author John Shirley. The book is soft cover, it has 270 pages and was published in 2007.

[edit] Publisher's Summary

Someone on Earth knew about the aliens. Someone battled them, and survived. Before Ripley, there was a first encounter. Aliens and humans have fought before! When a human spaceship discovers a vast egg-shaped vessel in Saturn's orbit, the crew powers in to investigate. Thinking the ship might contain usable metal for Earth, they force their way aboard. Three teams split up to explore the ship. But already the aliens have awoken. The first of all the battles unfolds.

there is a refrence in the book there assault rifles are called the m-270 and there are 270 pages in the book