I had bought 3 packs of the JP Enterprises trigger springs from Brownells to improve upon the trigger on 2 AR’s and 1 Armalite 180-b.
I went out this weekend and the “enhanced reliability” hammer springs just aren’t powerful enough to ignite Federal 55grain FMJ .223 sold in the ammo cans, despite their claim that it is (and several Brownells reviewers that didn’t experience this problem).
Nearly every third round I tried to fire wouldn’t go off with the JP springs. As soon as I switched back to the factory hammer springs, everything ran like a charm.
The other springs in the package work really well and are still worth buying IMO, but DO NOT install included hammer spring if you’re buying the kit.
Most searches on the subject of this type of spring kits, say only change the trigger spring not the hammer spring, which you have found out the hard way what many said will happen.
Are you sure you installed the hammer spring correctly. It is possible to install it wrong and get intermittent problems. I shoot the same ammo and many other brands with those spri gs in one of my rifles and it has been 100% reliable.
I remember reading somewhere that you should use the speed hammer (or lighten the standard hammer) with the lighter springs in order to have the same force on firing pin. I’m no physics buff, but it has to do with less mass at greather speed = same force.
Or like MK18Pilot said - use with JP Fire control parts.
My experience as a shooter in Euroland is that using a complete JP trigger set I’ve had no problems igniting Wolff, Barnaul, S&B, Geco or 5.56 military ammo.
