Hammer/Trigger pin hole wear

[SHERWINVILLARETE]

Just curious, is it normal for the black anodized layer to start chipping off after thousands of rounds? My lower is showing some aluminum inside the hole now.

[matemike]

I have never noticed that on my BCM, DD or S&W lowers.
Start by telling us what kind yours is.

Are you removing the fcg pins to see it? My initial thought is if the pins aren’t falling out (which they shouldn’t per their design) then don’t worry about it.

My buddy had a take down pin on a benelli shotgun that would slip out either direction just with gravity. So truth is that any pin hole could potentially wear out, however that is a completely different design pin system than an AR-15 fcg. He put duct tape over both sides and continued hunting with it though.

[SHERWINVILLARETE]

I have never noticed that on my BCM, DD or S&W lowers.
Start by telling us what kind yours is.

Are you removing the fcg pins to see it? My initial thought is if the pins aren’t falling out (which they shouldn’t per their design) then don’t worry about it.

My buddy had a take down pin on a benelli shotgun that would slip out either direction just with gravity. So truth is that any pin hole could potentially wear out, however that is a completely different design pin system than an AR-15 fcg. He put duct tape over both sides Andy continued hunting with it though.

Aero lower. It's sorta like a faded blackish aluminum. Not literally chipping but more like fading. Still measures the same diameter.

Going to run the KNS anti walk out pins for insurance.

[GH41]

Aero lower. It's sorta like a faded blackish aluminum. Not literally chipping but more like fading. Still measures the same diameter.

Going to run the KNS anti walk out pins for insurance.

What will the KNS pins do other than make your wallet lighter?

[docsherm]

What will the KNS pins do other than make your wallet lighter?

They hold the pins in place for triggers that are actually used, as the lower wears out and the holes get bigger. I have an SBRed DPMS lower that is almost 20 years old and has over 55k through it. It is on its 4th trigger. It has KNS pins because when you actually use something it will wear out, no matter if it is an Anderson Arms lower or a Colt.

OP- what trigger are you using? The pins and the lower may be slightly off. That can cause some movement and additional wear on the parts.

[RobertTheTexan]

Aero lower. It's sorta like a faded blackish aluminum. Not literally chipping but more like fading. Still measures the same diameter.

Going to run the KNS anti walk out pins for insurance.

Another option are CMC trigger pins. I’ve used KNS and they are GTG, but lately have been using CMC trigger pins. The CMC pins are a similar concept without the little bar. They are essentially two of the rear KNS pins, if that makes sense. Two threaded pins and I dab a little blue Loctite on - a very little, tighten down but not overly tight and you’re done. I like the CMC version only because they look a little cleaner.

[SHERWINVILLARETE]

I'm running a milspec trigger. The KNS pins not only prevents wear and walk outs but also improves trigger creep and reset. I love it

[SHERWINVILLARETE]

Another option are CMC trigger pins. I’ve used KNS and they are GTG, but lately have been using CMC trigger pins. The CMC pins are a similar concept without the little bar. They are essentially two of the rear KNS pins, if that makes sense. Two threaded pins and I dab a little blue Loctite on - a very little, tighten down but not overly tight and you’re done. I like the CMC version only because they look a little cleaner.


I did look at those. One thing that I didn't like about the CMC is that the hammer pin doesn't have the groove in the middle for milspec triggers. It's more ideal for drop ins. but im sure it works fine on a milspec. Just me being extra, I didn't want the hammer sliding inside the lower.

[lysander]

1) don't remove the pins unless absolutely necessary. Pulling them in an out is probably more detrimental than the slight rotational movement they normally see.

2) hard anodizing can be polished by rubbing, that is what you are likely seeing.

3) yes any time metal rubs on metal, you will have wear, put a little grease on the pins and don't mess with them until 5 or 6 k rounds

[markm]

I swear I'm on Arfcom.

pin holes don't wear out unless there's some underlying and wildly unusual circumstance. If the KNS concept was worth a shit, Geiselle would have employed the notion in his triggers.

Look at some of KNS's other goofball offerings, and you can get an idea of the nonsense they're all about.

[Stickman]

Not uncommon at all for seeing wear simply from the installation of the pins. I've seen wear and flaking from just putting the pins in place. Pins DO egg out a receiver over time, but we aren't talking about the couple hundred rounds most people put through their weapon in the course of a year. Tens of thousands of rounds are typically what is seen before notable wear comes into play from in spec components.

I would humbly submit the damage/ wear was from installation, but it doesn't change the validity of your concern, nor does it alter that using captured pins will cease/ slow acceleration.

[Stickman]

I swear I'm on Arfcom.

pin holes don't wear out unless there's some underlying and wildly unusual circumstance. If the KNS concept was worth a shit, Geiselle would have employed the notion in his triggers.

Look at some of KNS's other goofball offerings, and you can get an idea of the nonsense they're all about.

Not arfcom, not even close to being near that level, not yet. That place has its own slew of issues, and Brownells involvement or not, it isn't changing any time soon. The greater level of damage/ wear comes from anodizing issues, which are typically shown in flaking or chipping.

[SHERWINVILLARETE]

Not uncommon at all for seeing wear simply from the installation of the pins. I've seen wear and flaking from just putting the pins in place. Pins DO egg out a receiver over time, but we aren't talking about the couple hundred rounds most people put through their weapon in the course of a year. Tens of thousands of rounds are typically what is seen before notable wear comes into play from in spec components.

I would humbly submit the damage/ wear was from installation, but it doesn't change the validity of your concern, nor does it alter that using captured pins will cease/ slow acceleration.

Yeah you're likely right about the installation flaking some of the black anodized layer off. I'm sure it's not a big deal though as the anodize goes beneath the aluminum surface and hardens it. Heck, someone out there probably had tens of thousands of rounds through their 80% lower without an anodized pin holes without any wear.

I think these KNS pins will make this lower not egg out and make it last longer than me lol. This is my workhorse lower and I'm planning on taking it to the grave.

[Wake27]

Well, Geissele has stated multiple times that KNS pins should not be used with their triggers. There’s also lots of “knowledge” going around that there needs to be some movement in the pins so the KNS “solution” is actually causing a problem. I don’t remember who that was credited to, but IIRC it’s someone who should know better than the average end user.

Also, regardless of personal feelings on the company, no one can deny that Geissele triggers have been more thoroughly vetted than any other brand.


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[wetidlerjr]

I swear I'm on Arfcom.

pin holes don't wear out unless there's some underlying and wildly unusual circumstance. If the KNS concept was worth a shit, Geiselle would have employed the notion in his triggers.

Look at some of KNS's other goofball offerings, and you can get an idea of the nonsense they're all about.

Exactly! The voice of reason.

[GrumpyM4]

Also, regardless of personal feelings on the company, no one can deny that Geissele triggers have been more thoroughly vetted than any other brand.

Except USGI and the DoD has a gauging requirement for the Lower Receiver FGC pin holes in the -23 for a reason, even if the FCG has been switched out for a G trigger.

[Wake27]

Except USGI and the DoD has a gauging requirement for the Lower Receiver FGC pin holes in the -23 for a reason, even if the FCG has been switched out for a G trigger.

What’s your point?


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[docsherm]

Well, Geissele has stated multiple times that KNS pins should not be used with their triggers. There’s also lots of “knowledge” going around that there needs to be some movement in the pins so the KNS “solution” is actually causing a problem. I don’t remember who that was credited to, but IIRC it’s someone who should know better than the average end user.

Also, regardless of personal feelings on the company, no one can deny that Geissele triggers have been more thoroughly vetted than any other brand.


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And who exactly vetted the Geissele triggers that you sre using?

[SWATcop556]

After some clean up this one can continue but lets keep the the personal insults off the forum.

[vicious_cb]

I swear I'm on Arfcom.

pin holes don't wear out unless there's some underlying and wildly unusual circumstance. If the KNS concept was worth a shit, Geiselle would have employed the notion in his triggers.

Look at some of KNS's other goofball offerings, and you can get an idea of the nonsense they're all about.

Do pistol caliber ARs count?

Put blow back anything on top of an AR lower you'll end up breaking a few trigger/hammer pins and egging out your pin holes.

[hotrodder636]

Seems like reasonable, logical, cheap insurance on an SBR lower...especially one that gets used.


They hold the pins in place for triggers that are actually used, as the lower wears out and the holes get bigger. I have an SBRed DPMS lower that is almost 20 years old and has over 55k through it. It is on its 4th trigger. It has KNS pins because when you actually use something it will wear out, no matter if it is an Anderson Arms lower or a Colt.

OP- what trigger are you using? The pins and the lower may be slightly off. That can cause some movement and additional wear on the parts.