What's with Armalite saying Q1313 causes problems in guns?

http://www.armalite.com/library/techBulletins/tb6.htm

Actually, the product number is Q3131. The problem is that a few lots of this ammo which was produced in 1999 were loaded hotter than M193 spec. This may be to blame on bad powder that wasn't very consistent. But needless to say, pressures greater than mil-spec ammo fired in commercial spec chambers (which is what Armalite used at the time....and may still use) created some major problems with blown primers and extraction. This problem only affected certain lots of 1999 manufactured Q3131. Otherwise the other Q3131 and Q3131A are not affected and is regarded as very good quality ammo.

-CH

ah yea, little dyslexia there :P  thanks for explaining CH

During that time period the general concensus was to buy Q3131A instead of Q3131 to be sure to avoid problems.  Q3131 is domestic and Q3131A was manufactured in Israel for Winchester.  Many people still prefer Q3131A to this day becasue of this and wont buy Q3131 when given a choice.