Originally Posted By: shelton573Thanks for all the info guys. The double fire issue I read about stemmed from some type of jam screw issue I believe. I ordered one from brownells. They are running a deal where you get free two day shipping and a parts kit for a lower for $149. Decent deal I think. If anybody needs one they are back in stock now I believe. Thanks again for the info and I'll let you all know how it works out
theres a couple issues that can cause problems for these cassette style trigger groups. most of which are realted to the fact that many many ar-15's are over gassed out of the box these days, intentionally, for reliability reasons. problem being once you get outside of mil spec trigger group configurations, it can manifest in strange ways.
these cassette style triggers are known to have trouble in overgassed guns. even timney's will have problems on overgassed guns. ive been told its a carrier speed issue.
i had to put a heavier buffer in my ar15 to slow the carrier speed down when shooting suppressed - even on a 20" rifle length gas system. i was getting really weird trigger resets (or more specifically failures to reset) on occasion. called timney about it because i'd never had the problem non suppressed and they said its a known issue under supersonic suppressed fire with lightweight (carbine) buffers and non adjustable gas blocks.
you can either dial the gas back with an AGB, or increase the reciprocating mass to slow the carrier speed.
went to a h2, problem solved. smooth as butter. problem solved for $15 worth of tungsten weights from amazon or fleabay (i forget which) and about 5 mins of my life to swap them out.