LuckyGunner.com did very interesting test comparing brass cased ammunition to Brown Bear, Wolf, and Tula.
It is highly worth the read, there is a good bit of information to be had from their article. Some points I took from this is:
Bushmaster reaffirmed that they have lousy quality control with how their “Barrel nuts were torqued to inconsistent values: two had been torqued to approximately 5 ft/lbs”
They confirmed that Magpul back up sights are not good for firearms that will have high volumes of fire as “One MBUS sight cracked and fell off of the carbine to which it was attached due to heating and cooling cycles that negatively affected the polymer material.”
I don’t recommend Eotechs for several reasons, thanks to this test I can also add that “Excessive upper receiver heat did cause thermal discoloration of and cosmetic damage to the EOTech sights. Also, one CR123 battery in the XPS 2-0 ruptured – possibly due to heat – but both EOTechs, as well as the Aimpoint, remained functional at the end of the test. The manufacture date of the 552 was April of 2005; prior to the test, its battery spring “grommets” were replaced with a newer design, which markedly improved battery life.”
The biggest thing I took away from this test is that there is a huge difference between the Tula and Wolf ammunition. It was far more then I expected.
Head over to LuckyGunner.com to read more.