recently made aware of several reported (at least 1 on here) serious problems with frontier 5.56. mostly involving 55/62 gr. only used 75gr & i have used several C rounds with no issues and have about 400 left. so,am getting concerned about using it. i have a bunch of 5.56 TAP T2 and have found no problem reports about it. my simple comparisons show same weight,by look and web search same bullet,same POI in both my guns-16" not SBRs. rare blown primer reports in SBRs with 77gr IMI and anecdotal reports of it seeming "hotter" than some other 77s. anybody have anything on these issues?