Federal American Eagle XM855 62 grain green tip ammo

[*M4*]

Anyone know the story on this ammo. Purchased several hundred rounds on sale and discovered the cases look like they are reloads. Thought I was buying new ammo. What does the "X" designate in "XM855"? Does this ammo meet M855 military specification?

While investigation this ammo I discovered M855A1 ammo is very hot and hard on AR-15's. Throat erosion and loss of accuracy start to occur at only a few thousand rounds. Is the Federal American Eagle XM855 also harder on an AR-15 than your typical .223/5.56 loads.

I've got a new M4 I don't want to screw up!

Thanks

[Kdubya]

I'm gonna save you some trouble and let you know that commenters are going to tell you to use the search function. In the essence of trying to be helpful, your Federal XM855 is good to go.

First. The thought that they are reloads is likely the discoloration from annealing you're seeing on the case. It's normal and not a sign that they're reloads.

Second. M855 and M855A1 are two completely different loads. The latter is not going to be found for sale almost anywhere. Both are 5.56 pressures, and will be hotter than .223, but won't hurt an AR with a true 5.56 chamber.

Welcome to the forum and the AR life.

[TomMcC]

Federal "X" series ammo isn't known for its prettyness. It's my understanding that the "X" means that the ammo didn't meet some minor aspect of the mil-spec. Some here have a much lower opinion of this ammo. I personally stop buying the stuff because I like my ammo to look like it was put together with more attention to detail.

[markm]

It's not reloads. Sparkly brass just isn't a military thing. The ammo is made from a regular over-run or minor spec issue components. It's a standard production item almost always available. It should be decent blasting ammo, although the green tip/ss109 bullet doesn't do anything particularly well.