Are there any real advantages or disadvantages to them?  To be honest I just think they look cool but am trying to justify buying them with something other than, "Check out my new tacticool trigger pins"

I always said no.  That was until one of my pins got loose and nearly fell out.  Now I'm a believer.

I used them on my first build, but not on the next two. Now I actually prefer the "smooth" look without them. They looked cool at first, but then became gaudy to me. YMMV.
It's nice to have a set around, in case you do run into problems, but I have yet to experience such (and probably never will with the minimal amount of rounds I can afford to shoot!).

Never had a pin issue in any of my Army issued M16 or M4.

I don't use them myself.

KNS pins are stainless steel. A softer steel than normal pins, and tends to gall. The KNS pins also have sharp edges on their ends, which like to tear up the J pin on the hammer while installing. And depending on the generation of KNS pins, you will have at least one hollow pin, obviously weaker than a solid pin.

They're slightly undersized too. So instead of a correctly sized pin harmlessly rotating, you have a pin that slams back and forth in the trigger/hammer holes.

Never had them on any of my rifles. If you run your stuff hard and like the way they look, buy them.

I bought a set for my first build along with a few other tacticool things and deemed them unecessary in the end. I ended up upgrading my trigger instead and found the pins that came with were WAY better quality and a better fit.

Now when i show my rifle to guys who really know their stuff, they'll say "glad to see you don't have a ton of ninja crap hangin off it"

I still think they look cool though so do whatever you think I guess.

bling unless your existing pins are walking.

I use them in 80% builds since the lower receiver holes aren't anodized.  Can't hurt, may prevent some wear, and if the holes are a little bit out of spec, might help keep the hammer and trigger pins properly aligned.

They eliminate pin hole wear.
They don’t walk.
Some people claim their trigger feel is better.

They currently don’t come in the right size for Geissele FCG’s.
They are an added maintenance complication.
Pin holes wear very slowly.
Pins don’t walk in properly assembled lowers with good parts.

If you need them, use them. If you don't, save your money. Don't buy them because they look cool. Then again it's your stick, build it how you want.

I'm thinking about getting them for the gun I built my dad, first time shooting it the trigger pin started to walk out.

I use the JP Anti-walk pins in 9mm,.45acp, and .22LR blowback lowers that are harder on the hammer pins, if you do some research a lot of the guys who run pistol caliber AR's recommend them. I don't use them on 5.56 builds uness I'm running an older preban lower with pin holes that are egged or slightly enlarged. I shoot thousands of rounds a year and I'd guess most people that just want them because they look cool won't be shooting thousands of rounds out of their AR ever. Like a previous poster stated they are a PITA when taking our your FCG for cleaning/maintanence purposes.

Pretty much my thoughts...

ps...it took my AR seven years to have issues with the pins.  The problem is that if you loose a pin, it can cause an unrecoverable stoppage.  My concern was that this would happen at the worst possible time.  I was lucky, mine happened at the range.

All I can say is that it gets in the way if try to use Tactical Link's bolt release lever.

Just buy them.. they were on sale for $20 last week at primary arms.

I do them on all my color match builds because I like the color. Not everything had to be practical!!!
I also NP3 them and NP3 my FCgroups often.

In the grand schema of things $20 is very very minor compared to the cost of a match barrel, nice rail or Geissele trigger.

I've never dealt with the KNS pins, but I did have an AR with a basic trigger and the JP oversized pins. I noticed they cleaned up a lot of side to side slop so I've use those pins on any build that utilized a basic trigger kit.

I've never even had a PTAC pin walk, let alone better quality parts...

Drop in triggers usually come with them. Timney and CMC come with anti orate pins.  Get a drop in and tell the haters to bug off.

I have a set on my first build because when everyone was panic buying I couldn't find any other set of pins and I really just wanted to finishy lower.

KNS anti-rotation pins are a fix for a "maybe" problem.  In some situations, the hammer (and trigger to a lesser extent) pins can rotate enough to wear their holes in the lower, making them either non-round or oversized.  It would take a LOT of rotation to cause that, but it's a possibility.  They are NOT for anti-walk.  Anti-walk pins have C-clips (or E-clips) to keep them from going left or right.  Anti-rotation pins are to keep the pins from hurting your lower.

Don't be a troll.  This is an over abused topic.  Buy them if you want them.
 

They are kind of waste imo, but if you had say a SBR lower, or M16 lower they may be worth it as insurance to keep the pins for wearing the holes, this has never been an issue for me, even on the numerous M16s I have seen over the years, including Vietnam era ones.

This was my concern. I used them on my first build, but that hammer pin was HELL to get in (there's no "guide" tip for that). I literally had to hammer that thing in. That led me to A) this would not be "field repairable" to work on, and B) I pray that my J spring survived. I will NOT be using them again. Engel, thank you for bringing up an issue that no one seems to mention, but is very important.

Anti rotation came about because the guys with full auto lowers - who could well afford to use them - eventually suffered some wear. KNS responded, we are talking about a lower that now retails for thousands of dollars. Full auto M16's trade for $10,000. So, some KNS is a nice thing to have.

In that use, the cyclic rate and harmonics can combine to get the spring tails to jump out of the retaining grooves and that is how the pins walk out. PROPERLY ASSEMBLIED guns don't typically have that problem. 22 years Reserves with two to four qualifications annually, I never saw any full auto or burst weapons ever have the problem, and we frequently had excess ammo to consume at the end of range fires.

In the build your own at home crowd, there is a possibility that a combination of parts might contribute to rotation or walking. One method to prevent rotation is to simply hammer the end of a pin slightly so that it's oval shaped a few thousandths to take up the slack. Insert the opposite end, and tap the last bit flush. It should take up the slack and prevent rotation. That's how armorer's do it.

They don't have the budget or access to KNS pins, and they don't need to bother, either.

As for walking out, it goes to proper assembly, and not using GI springs. Light springs can and will increase the probability of jumping out of the retention slot due to the harmonics of operation. It's a spring that no longer is GI spec, that's the issue, not the pin. If the tail of the spring has reduced tension to get the trigger lighter, it's what has been changed. Sometimes there are unintended consequences.

Looking at the use of the M16/M4 with over seven million produced and used in combat for the last 45 years, the standard GI setup is reliable. What or how it's used in combination with other aftermarket parts is where the majority of the concern is from.

They are $20 who cares.

Tried the cmmg lpk pins on my first build, gritty pull, muddy break. Put the KNS pins in, smooth pull, crisp break. YMMV.

use the Gen 2's in both my AR's utilizing the ALG ACT triggers........are they tacticool? Sure, but they do serve a purpose unlike a lot of mall/range ninja stuff you see now days.

They came on a rifle I purchased. They create a nice place to rest your finger between shots. I don't even know if they do anything truthfully since guns existed for years without them and continue to NOT be on an overwhelming majority of rifles.

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