Tedward Wrote:...we need facts and proof of your statements.
Read this.
http://www.gunsumerreports.com/review_fi...es_001.php
Not opinions, facts. Post them.
I'm not sure what you're looking for, but the link you posted supports what has already been stated in this thread. Here are a couple of quotes from your link:
Quote:...7075-T6 has nearly twice the strength of 6061-T6. Because strength also relates to hardness, 7075-T6 aluminum has a Brinell hardness of 150 and 6061-T6 aluminum has a Brinell hardness of 95. Clearly, the 7075-T6 alloy is stronger and harder than the 6061-T6 alloy and would be the better material for making upper and lower receivers.
Quote:Bottom Line:
If you are purchasing a new AR style rifle or receivers, you should make sure the receivers are made from 7075-T6 aluminum alloy material.
Drifter