I researched many drop in triggers and had several in the "cart" for purchase, but decided, I dont want a 2.5-3lb pull trigger on this rifle...and I don't need a drop in...Im very confident in my ability to fit a trigger group in an AR style rifle, up to and including milling the receiver for over sized pins should I want to.
So I started looking at replacement trigger groups.
A company called ALG Defense kept popping up in forums, blogs and reviews...
I looked at their offerings and the Advanced Combat Trigger (ACT ) seemed to fit the bill for what i wanted
The ALG Defense Advanced Combat Trigger (ACT) is designed for those shooters where tradition, value and regulatory concerns are of primary importance. The pull of the ACT is very similar to a standard mil-spec trigger, however it is sharper and the grittiness of the stock trigger pull has been removed while the traditional reliability of a stock trigger remains. The pull weight is not lower than the M4/M16 minimum weight specification of 5.5lbs.
NOTE: Included with the ACT is the Purple reduced power hammer spring as well as a full power hammer spring.
Priced at $69 I decided it was well worth the buy in for an experiment and at worst, Id resale it at 50% in an instant and be out not much more then I might blow on lunch for the wife and I most every weekend.
I purchased the ACT trigger and a Geissele Automatics - Trigger Fitting Pin for ease of install and no need to machine a tool in my non spare time these days.
The packaged arrived 4 days after purchase, with just standard shipping.
The trigger group came with instructions that I "think" will make sense to most anyone that has done their homework. Its hard for me to judge that as I have been working with the M16/ M4 platform for a lot of years to include the Army's Armorer training more then a few years ago..
Install took minutes, and that included swapping the light purple spring for the "heavy" 5-6lb Tan spring
The difference between a clean, well lubed original SIG trigger (and every Colt M16/M4 trigger as it came from the supplier) is night and day.
The grittiness is gone, the brake is clean and crisp with just a tine bit of creep, but its even and smooth. my trigger with tan spring breaks at 5.4lb
I will try the purple light spring as well after I put a few hundred rounds down range with this spring.
Bottom line, if your looking for a "nicer" trigger then came in your off the shelf AR rifle, do not want or need a ultra light pull trigger, shot 'well" with a stock trigger, the ALG ACT trigger might be right for you at a buy in of just $69