I had the chance to do some blasting this weekend, Saturday and Monday actually.  I was shooting the Oly, 11.5" bbl with long flash hider.  Anyhow, Saturdays fodder was Winchester white box 5.56.  I ran out so on Monday I switched to Federal XM193.  Both days it was overcast, similar weather.  I was freekin amazed at the difference btw the two loads.  The Winchester (which is what I'm used to) creates just a bit of flash noticable on the hider slits.  On the other hand the Federal shoots a flame about two feet long for the hider!  My wife commented after she fired it, 'it's like shooting a flamethrower!', and it was.  The Federal seemed to have more 'kick' as well.... for an AR anyhow.  For what it's worth I used one of those british mags the whole time, it worked flawlessly.

Federal XM193 is definately a hotter round.
I believe the winchester is 55 grain and the federal is 62 grain. This could explain the increase in muzzle flash between the two loads.
So, the british mags functioned flawlessly with both loads. I guess i'll give in and purchase some SA80 mags.

Agreed 100% here.

Several times I used LC, Q3131A and WOLF ALL mixed up in a few mags. Ran two-three mags through my rifle just for a little taste test. Rifle & magazines functioned flawlessly.

Every time the LC was shot, it was obvious with the fireball out of the barrel. The Q3131A was a noticeable pop and the Wolf looked/felt like a 22 caliber cap gun.

I recommend it trying it that way.


btw, no that Federal (LC) is 55 grain not 62.

Yep, the federal was LC2000 55gr.  I like it!  

X193 is 55 grain FMJBT

hehe, yeah I'm anal

XM193 is the stuff for all around IMO.  Much more fun to shoot and if TSHTF you've got good ammo for it.