It seems your second AR is functioning much better with these.
Even though 3% failure rate is still higher than what I see.
I shot my Sig516 the other weekend 300 rds w/o the use of heavy srping and got 1 light primer strike. Which is at least good enough for training and in SHTF probably good enough when the other ammo runs out (because it was too expensive) or is ruined (because the nicely laquered and sealed rounds will last thru the most humid storage).
Thats a failure rate of 0.3 % so one order of magnitude better than what you get and about in line what normal economy ammo does with unmodified weapons.
Even though I seem to remember having gone thru 1000 rds before without any light primer strikes or any other issue but I dont remember 100%.. that might have been with the stiffer spring....
I will gladly send you Wolff Hammer Springs I found two in my stash that I
think are the Wolffs .
But since they were not in original packaging I can't be 100% (my big box of original spares is at the BOL I will be there in 3 weeks).. Well I am 95% on one of them since I had marked it's packet by hand "Wolff" and the other one looks/feel same.
IMO they are best used in conjunction with a smooth trigger group like this one:
https://www.righttobear.com/Enhanced-Nickel-Teflon-Trigger-Assembly-p/enta-01.htmor anything thats polished as IMO the wolff Hammer springs accentuate any creepiness or roughness that may exist in the pre existing trigger.
Are your pre existing Hammer Springs for sure Milspec and not softer?
Can you take a close up picture for me of the red X FP?
I also have a couple of RedXs on hand, one in original packaging, so I would love to compare your FP...
Cannot explain your problems since I tried it w/o stronger springs in several ARs and your symptoms seem broadly similar to what I got when I tried the milder modified FP w/o any heavy springs.
By now I converted at least 3 or 4 of my ARs and pulled the heavy hammer spring and replaced with a PSA milspec spring.
I think I have gotten in the past passable results even with a spring from the RKB kit linked above which is about a lb less than milspec.
PS: If you ever get frustrated by it I will take the ammo off your hands for what u paid for it, if the shipping isnt too extreme.
PS2: Can you take a close up pic for me that shows the internals of both your trigger groups? From the top of the open lower receiver. Close enough so we can see where the "legs" of your hammer springs are?