I used KNS pins on my first build before I had any knowledge and before I knew they were unnecessary and serve no practical purpose. They are pretty much like throwing $30 down the drain. I never messed around with uninstalling them because they were the updated version with the stronger pins so I knew they wouldn’t hurt anything. On this first build, I used an ALG QMS trigger for reference.
Fast forward to last week. I was working on my 3rd build and decided to use another ALG QMS since I was happy with the first. I used the stock pins that came with it and everything functioned completely fine. What I noticed was that it had a little bit of creep. Just a tiny bit but it was still noticeable. I wouldn’t have thought anything about it except that the first QMS I installed had absolutely no creep whatsoever. I decided to remove it and install it again just for good measure. I got the same results.
I then began to think if the KNS pins had anything to do with it or if I just got really lucky with the first trigger. I wanted to find out so I decided to use my $30 Amazon credit on some KNS pins.
I got around to installing them last night and to my surprise, the creep went away. It felt exactly like my first ALG trigger.
So here’s the question. Was this just a coincidence or is there something technical going on? I’m not the slightest bit versed in all of the technical aspects but does removing the slight amount of movement in the trigger pin remove a slight bit of creep?
Just for the record, the reason why I use the word slight is because I tried the KNS pins out with a Mil-Spec trigger that was included in a DD parts kit and I didn’t notice any reduction in creep. I’m assuming it’s because the trigger that came in the DD LPK had too much creep to start with.
I’ve found that for the most part, mild creep will go away as the parts settle in. KNS pins probably are helpful in niche circumstances, competition triggers, etc.
Eh…I’ve already removed the trigger pins 5 times and don’t feel like doing it again. I think I’ll just keep the KNS pins in for now. They won’t hurt anything and the trigger feels better with them.
The advantage of the KNS is that the side plates keep the pins in a fixed relationship; the pins cannot move away or towards each other as the trigger is pulled, while milspec pins can move towards each other just a bit as the trigger is pulled, adding just a bit to perceived creep. Don’t think rotation has anything to do with this. While I had the same positive feeling about the trigger pull with my KNS pins as the OP, I ended up with the same creep free trigger pull by using Geissle’s pins, which are slightly oversized compared to milspec, while made of harder steel and requiring no allen wrenches for disassembly, compared to KNS. Not sure if the ALG pins are the same as the ones sold with the Geissle trigger sets. If not, I would get a set of G pins.
This is at the sacrifice of the pins being allowed to roll in the lower. Without that, all the friction is forced onto the pin. Possibly a non-issue… but guys have made the argument over the years that if the pin fails, it can damage the lower pin hole.
I don’t think the original style pins are likely to rotate in the receiver. The springs put a bit of pressure against the pins and there is a bit of natural sticktion when it’s steel & aluminum. It only makes sense to size the pins & holes so the harder hammer & trigger rotate around the pin than to have the pin to rotate in the aluminum receiver and cause fretting.
The pins fretting in the receiver isn’t a problem, otherwise we’d be complaining about all the threads concerning the use of steel bushings to repair worn pin holes
Yep. A lot of guys buy the KNS pins thinking they’re saving their lower. But every time that comes up, several prior service guys will note the ANCIENT M16s they saw in the military racks that are still going.
Im not really worried about my FCG holes egging out. Like you said, it takes more trigger pulls than I could ever put on it and is it ever did happen, there are fixes for it.
I can see why someone would want to use them on an 80% lower that was only Cerakoted and not Anodized. I don’t think Cerakote is as hard as anodizing.
Look closely at your pins as you cock the hammer and press the trigger. The hammer pin will rotate with the hammer due to the J-Spring inside the hammer that captures the pin.
When pressing the trigger, the trigger pin will rotate slightly but not nearly as much as the hammer pin. It pretty much just rocks back and forth.
This is where I see KNS pins as beneficial. Not necessarily from wear issues but from out of spec issues. When people see the .156 pin hole spec and ram a 5/32 (.15625) drill bit through the lower that actually makes a .158ish hole not realizing that there wont be a level 3 anodize to build the surface back somewhat. Then they install .154 pins and wonder “why so much slop?” KNS pins will actually keep the trigger to hammer relationship at the right distance.