A big thanks goes out to those I got trigger parts from. I did some tweaking and testing in my AR15 And also checked for reliable primer ignition using CCI 450 primers in Federal cases. These are small pistol magnum primers with a harder cup than the CCI 400 and harder than the CCI 550.. Harder or possibly thicker.. either way it is the one that will not pierce when overloaded,,Yes I tested over loading cases until primer failure in .223. (failure meaning piercing a hole into primer) The CCI 450 did not fail when others did . Now To start with i took a cheap mil spec trigger assembly and tested for trigger pull weight. 6.4 pounds to set it off. Now yours can be different with the same parts as many lowers the pin holes can be just a tad different position. Mine repeated 6.4 lbs many times. The Hammer took 5.6 lbs to begin moving it back...I positioned the scale hook at the point on the hammer where it meets the top of the lower receiver. Now I modified the spring on the hammer This took less pull to begin to move it back. 3.2 Pounds. I get reliable primer ignition at that weight.. but my gun stays clean and not carboned up. Trigger pull was reduced. 4.4 Pounds. Now I polished the trigger end with 1000 grit wet sand paper, I made it wet also. This resulted in. 4.1 Pounds. Trigger pull weight. Then I tweaked the trigger spring. I bent the legs up at a slight angle. Pictures below. 3.8 Pounds. It is much lighter and smoother than stock I get reliable ignition and no funny business happening. Now this is just some information I gathered for my gun. It is cheap and easy and more time was spent measuring than actually tweaking the parts. Here is a picture of the stock spring and the modded ones ..Modded ones are bent and cut. 1 leg on the Hammer spring was cut to 1/4" long. You may not need to cut it if you bend it ..I had cut mine before any bending took place. You do not need to stone the edge of the trigger,,I did stone it to reduce trigger pull distance.