Although I was perfectly happy with the standard AR trigger in my GPR, having a Geissele SSA in my Recce build made me curious about the ALG QMS so I bought one to try out.
I was having a carrier ion bonded, so I tossed the QMS hammer and disconnector in to get ion bonded as well, just for S&Gs. After getting the parts back last week, I installed them in my GPR and took it out to the range this past weekend for a test run.
The QMS has no grittiness or hang-ups. The pull is crisp and consistent. However, with the standard mil-spec springs provided by ALG the pull is much heavier than I anticipated -even with the added slickness provided by the ion bonding of the hammer and disconnector. Subjectively, it is heavier than both the standard AR triggers I have used in other setups (each with under 2k round count). I can say with confidence that it would meter at over 6 pounds.
Ideally, I would like a 5 pound pull. I’m tossing around the idea of switching out one or a few of the springs with JP springs. This is what I am looking at:
I think the general consensus (including Bill Geissele’s) is that replacing the hammer spring with anything less than full power is not advised. Namely for consistent ignition of primers.
Now, I have not experienced a significant weight difference replacing just the trigger spring (with the yellow JP’s), but that’s just my experience. I prefer to leave the mil-spec stuff well enough alone.
You’re right. I did not read the original post close enough. I thought the complaint was that the QMS trigger pull was heavier than the standard AR trigger pull
For $45 a guy can’t expect much. But after ion-bonding the hammer and disconnector I was surprised that the pull, although smooth and relatively crisp, was noticeably heavier than both of my standard AR triggers. Subjectively, my QMS was also noticeably heavier in pull than two of my buddy’s ARs. That’s four ARs with standard mil-spec triggers that my QMS was heavier than when compared side by side (I really need to get a trigger gauge on this thing).
Running multiple successive 2x2x2 drills my trigger finger actually started to get fatigued due to the heavy pull. This made me think about playing around with the springs, but I am going to leave it and see how it is after a few thousand rounds. I am willing to bet the springs will break in and the trigger will polish up even more and I’ll end up with a totally decent trigger, much like I would expect any standard AR trigger to end up after some use.
My take-home message is that all in all, the QMS is at least initially smoother and crisper than a standard AR trigger, but I wouldn’t bother removing a nicely broken in mil-spec trigger and replacing it with one.