User blog comment:MerchantofDeath/They dissed us......./@comment-1863708-20101001054243

I'm super late to this party, but I have a comment.

The reason the XM8 project was cancelled was because the XM8 system did not hold up well to sustained combat situations. The plastic polymers that made up the frame began to distort, and in some cases, MELT due to the head caused by sustained automatic fire. That's not good. The polymer thing, one of the basic parts of the XM8 project, was too flawed, so the project was cancelled outright.

Read the XM8 wiki article for more.