KNS Anti Rotation Pins....Is it a fluke or is there something technical behind it.

[soldier_twiggy]

When I ran the test fire pit for a local AR builder, a few of our OLD test lowers were a little "wallered out" (that's a technical term) and were continuously breaking hammer pins and having trigger pins drift. We installed KNS pins and stopped that problem.
That being said, some of these lowers saw 300-1000 trigger pulls 5 days a week for years before they started failing. So I don't think KNS pins are necessary unless you get paid to shoot 24/7, like Jerry Miculek.

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[03scgt]

ive got a lower that you can physically see the factory pins moving up and down in and not just rotating.Ill be honest and say Ive never actually paid attention before and I dont have another rifle with a factory trigger in it to compare.Only reason I looked close enough is because the pins always seem to stick out of one side of the receiver or the other and I can push them a small amount.The trigger spring is installed correctly and the lower is factory assembled

how much movement would actually be considered normal? lol

[HuttoAg96]

It's just a .22, but I've got an M&P15-22 (polymer lower) that occasionally stops functioning when one of the hammer/trigger pins walks out and the FCG gets bound up. KNS pins are a cheap, easy fix for that issue. I wouldn't expect that kind of thing to happen on an in-spec metal lower. To me it is a possible solution when there is a known problem, but not something I'd do preemptively.

[soldier_twiggy]

ive got a lower that you can physically see the factory pins moving up and down in and not just rotating...Only reason I looked close enough is because the pins always seem to stick out of one side of the receiver or the other and I can push them a small amount...

how much movement would actually be considered normal? lol

Not that much! If your pins are walking, they're too loose. And if the pins ends will move vertically and horizontally, you're looking at future broken pins and weapon failures.

Could be a FCG hole size problem, but I'd be more inclined to check out the pins themselves. I'll bet they're on the small side.

Out of curiosity, what make FCG and Lower are we talking about?

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[03scgt]

Not that much! If your pins are walking, they're too loose. And if the pins ends will move vertically and horizontally, you're looking at future broken pins and weapon failures.

Could be a FCG hole size problem, but I'd be more inclined to check out the pins themselves. I'll bet they're on the small side.

Out of curiosity, what make FCG and Lower are we talking about?

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to be perfectly honest Im not going to name the company without giving them a chance to make it right.I wasnt even sure if it was abnormal or not as ive never paid attention very closely

ill upload a short upclose video

[soldier_twiggy]

to be perfectly honest Im not going to name the company without giving them a chance to make it right.I wasnt even sure if it was abnormal or not as ive never paid attention very closely

ill upload a short upclose video

That's cool. I wasn't looking to bash based on name. Was planning on checking Google to see if that was a common issue with their FCG's or lowers. Best of luck.

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[HD1911]

When Bill Geissele speaks, I tend to listen. If he thinks the KNS pins are a bad idea.... well, that's a good enough reason for me to stay away from them

[SteveS]

They look tacticool that is all that matters.

[markm]

I was doing pin observation last night. The hammer pin slightly moves when the hammer cocks... then the pin spins forward on each hammer drop. No way am I messing with the natural parts movement by installing this nonsense.

[soldier_twiggy]

Both my hammer and trigger pins on my 7.62 DPMS just "rock" with the movement...neither really "rotate".
Whereas the hammer pin on my Bushmaster (Windham) rotates about 10* each hammer stroke. And the trigger pin doesn't move at all it seems.

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