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View Full Version : What is this called and what does it do?


NOTARPilot
02-25-2011, 11:23 PM
Thanks
http://www.performanceboats.com/gallery/data/500/medium/AR_Question.JPG

five.five-six
02-25-2011, 11:24 PM
it keeps the FCG pins from walking

Dreaded Claymore
02-25-2011, 11:27 PM
Anti-walk pins. Basically the hammer pin and trigger pin are connected to each other to help keep them in place. It's necessary only on older rifles, where the holes have been worn so much that they're loose, and the pins will "walk" out of them otherwise. Also, some people put them on because they like the look.

pacrimguru
02-25-2011, 11:35 PM
KNS Anti-Walk Pins. those shown above are Gen 2, these shown below are Gen 2 Mod 2.

"KNS Precision Anti Rotational Pins keep your trigger and hammer pins in place so that they don't "walk" out of the receiver. On harsher systems such as 9mm or suppressed AR's, they reinforce the hammer pin which is known to fail.

These are the Generation 2 Mod 2 pin sets. They are the STRONGEST pins that can be produced and were designed to withstand the high impact of full and semi-automatic 9mm and .223 suppressed weapons. "

http://www.valkyrietactical.com/images/KNSG2M2K-1.jpg (http://www.valkyrietactical.com/product_info.php?products_id=1717)
http://www.valkyrietactical.com/product_info.php?products_id=1717

Reductio
02-25-2011, 11:36 PM
http://www.midwayusa.com/viewProduct/?productNumber=528425?cm_cat=Cart&cm_pla=ProductDesc

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=581214

Sacramento Black Rifle
02-25-2011, 11:36 PM
As you fire the rifle the pins will rotate with the recoil of the gun. As that happens over a period of time elongating the trigger and hammer pin holes. The anti walk/rotation pins will hold the pins in place so that wont happen.

Cokebottle
02-25-2011, 11:37 PM
http://www.riflegear.com/p-610-kns-gen-2-anti-walkrotation-triggerhammer-pin-set-154-diameter.aspx

http://www.riflegear.com/images/Product/medium/610.jpg

Screws have a small amount of dry loctite on them. The pin with the "teeth" on the ends goes in the hammer hole and the teeth are rotated to point at the trigger pin. Threaded pin goes in the trigger. The arms slip over the teeth and the screws lock them into the trigger pin.

The arms prevent the hammer pin from rotating with the hammer, reducing wear on the lower.

Ak707
02-25-2011, 11:37 PM
I been wondering the same thing

Ak707
02-25-2011, 11:38 PM
People like the looks.?
Wow I think it's god awful ugly

five.five-six
02-25-2011, 11:54 PM
People like the looks.?
Wow I think it's god awful ugly

oh no, they are tacticool, would not enter a mall without them

Colt-45
02-26-2011, 12:00 AM
Nice I was wondering the same thing. Learn something new every day. Thanks Calguns :D

ChrisO
02-26-2011, 12:27 AM
Ok so it PREVENTS wear on the lower. Hmmm, I might get some... Better safe than sorry.

JeffM
02-26-2011, 12:36 AM
Ok so it PREVENTS wear on the lower. Hmmm, I might get some... Better safe than sorry.

Do you have an NFA gun? See my sig line.

Mr.Caketown
02-26-2011, 1:35 AM
Do you have an NFA gun? See my sig line.

your sig line is whack



also to those who dont have anti-walk pins ... aside from keeping the pins in place they also make a cool finger rest when keeping the finger off the trigger. I bought them as an impulse buy and they dont look to bad , but i probably wouldnt buy them again.... unless they offer a matching black color :43:

GUNFREAK
02-26-2011, 6:30 AM
I'm not toally convinced that theese are necessary. In my experience with the military, we fired very old M-16A2 rifles. They have definitely had plenty of rounds put through them including three round bursts. These rifles were almost as old as I was. Never were the pins "walking" out a problem. Even after I got off active duty and entered the reserves (where the rifles were definitely older than I was), this was not a problem.

Maybe something was done in the armory that I was not aware of but I'm still not sold that I need these for my rifle.

Ruiner
02-26-2011, 7:48 AM
Don't need em. Although I do have em on my rifles because I bought them before I knew any better. I already had them so I might as well use them. Won't hurt anything, won't help anything either.

vintagearms
02-26-2011, 8:56 AM
I'm not toally convinced that theese are necessary. In my experience with the military, we fired very old M-16A2 rifles. They have definitely had plenty of rounds put through them including three round bursts. These rifles were almost as old as I was. Never were the pins "walking" out a problem. Even after I got off active duty and entered the reserves (where the rifles were definitely older than I was), this was not a problem.

Maybe something was done in the armory that I was not aware of but I'm still not sold that I need these for my rifle.

Pretty much but tacticool is still in...Nothing was done to the rifles except maybe change the hammer spring. They were developed for NFA lowers that cannot be replaced, only repaired.

bohoki
02-26-2011, 9:05 AM
i bought the anti walk pins that have an e clip the anti rotation ones seem like a neat idea but they are always made inefficiently

seems to me they could just make them out of 3 identical parts

the rods and the pins and the screw each pin would have a thread and on the opposite the anti rotation key

i just used a drill and a file to cut my stock pin grooves deeper so they wouldnt walk out

CALI-gula
02-26-2011, 9:54 AM
Sorry; I've never needed them and I've been shooting and building ARs since at least 1984.

I've seen them for sale and thought to myself "wow, what a good idea" and I think if this WERE a problem that arose on a specific rifle, you should 1) change the pins first - maybe the tolerances are bad? 2) if it continued to be a problem maybe bad specs of the receiver are the culprit - then I guess these would be a good purchase.

However, that's how I see them; a fix for a problem and not needed unless the problem was constant. I've just never come across the problem where I needed them - so to buy them without having the problem is an unnecessary expenditure.

.

MacOtac
02-26-2011, 10:01 AM
Worthless.... Just made to make money. With all my military experience and 1000's of rounds that issue never arises and the need for that thing. If it was a really issue it would be on military weapons. JUNK!

evolixsurf
02-26-2011, 2:10 PM
I got them after my instructor told us a story of his pins walking during a class. I figure this... Ive spent over 2k on my AR and now have nearly all the best parts. Why would I leave the regular pins in there and have then possibly walk and ruin my class/gun when all I have to spend is $30? Additionally, the lower is the one part you cant replace very easily... I dont want those pin holes getting any bigger ever, so its like preventative maintenance.

Please understand, if your not shooting thousands of rounds and training all the time, then no, they are probably not necessary.

Seems worth the money to me.

Merc1138
02-26-2011, 2:15 PM
Worthless.... Just made to make money. With all my military experience and 1000's of rounds that issue never arises and the need for that thing. If it was a really issue it would be on military weapons. JUNK!

This.

With the countless numbers of m16 and m4s in service, with an even more ridiculous number of rounds fired, if this were an issue it'd be included on service weapons. Now if I had an NFA registered lower receiver, then yeah I'd spend the 30 bucks, but otherwise it's just one of those products designed to nickel and dime people into blowing more cash.

"Well that's a good idea and it's only $30, check out that good idea and it's $20, oh look another good idea for $40, that's only $10 I'll pick it up anyway" and now you've blown an extra $100.

Jpach
02-26-2011, 2:17 PM
I actually NEED these for my gun to function. I bought an aftermarkey trigger and hammer + pins, and while firing the pins walked out and my gun would no longer work. That is a real PITA when you actually need to shoot at things that are living (I was rabbit hunting).

Besides this new trigger, I have never experienced a situation where my standard pins walked out. I highly doubt many people have. But hey, if you want it, get it. And if you get an aftermarket trigger and hammer, get it just to be safe.

odysseus
02-26-2011, 2:33 PM
Not really needed unless wear has caused an issue, and that wear is usually hard to obtain. Think of all the rifles functioning right now in the sand box for years without these. It's unnecessary to apply these to a newer fully fine lower.

However I have heard of, and originally I think these came from the need, that some lowers were\are built with slightly out of spec points drilled through. The standard pins were never seated to spec. You could buy some over size spec pins, but some people felt better with these in place too.

slick_711
02-26-2011, 2:40 PM
I actually NEED these for my gun to function. I bought an aftermarkey trigger and hammer + pins, and while firing the pins walked out and my gun would no longer work. That is a real PITA when you actually need to shoot at things that are living (I was rabbit hunting).

What kind of monster rabbits do you hunt that you need to fire multiple rounds at a time? :p

bigbob76
02-26-2011, 2:53 PM
What kind of monster rabbits do you hunt that you need to fire multiple rounds at a time? :p

Better safe than sorry. You remember When Jimmy Carter got attacked by a rabbit?:D

NYY
02-26-2011, 6:35 PM
yea pretty helpful. haha had my pins walk out on me during a firing session... scariest moment of my life

arsilva32
02-26-2011, 7:02 PM
People like the looks.?
Wow I think it's god awful ugly


i'm with you, i don't like the way it looks ether.

Outta Control
02-26-2011, 7:26 PM
I have them on both my 80% milled lower and I could see where if I messed up on drilling the holes a bit larger than their supposed to then the anti-walk would be a good solution. So I wouldn't discount them but also it does have a tacticool look to them.

http://alvin.smugmug.com/photos/1182684029_hDSMx-M.jpg

$P-Ritch$
02-26-2011, 7:33 PM
Hey Outta Control,

Did you do the engraving yourself on the 80%? What does the full-auto marking say?

Outta Control
02-26-2011, 7:36 PM
I had someone do the engraving for me and the none functioning portion on the selector switch marking says "plague"

Jpach
02-26-2011, 10:21 PM
What kind of monster rabbits do you hunt that you need to fire multiple rounds at a time? :p

LOL, They can be quite big in New Mexico. And they can be quite plentiful too, so it really sucks when you need to shoot but cant because your previous round happened to pop your pins out!

The rabbits are usually VERY close and since I have an ACOG it can be very tough to figure out where the point of impact will be in relation to your POA at such close ranges. Sometimes you need to pop a few off to get an idea lol.

captbilly
02-27-2011, 9:43 AM
If you are running a basic AR, and have a pragmatic view about the lower eventually wearing out, then there is little reason for using anti walk pins, but if you are using certain upgraded trigger systems or you want tighter tolerances on your trigger group then the anti-walk pins can be very useful. Some upgraded triggers, like the Geissele and Rock River, come with oversize pins to keep the tolerances tighter, and therefor trigger pull more consistent. My JARD trigger came with no trigger pins (you were supposed to use the old pins) and the pins were not held well by the trigger group so they would just walk out after a few shots. With the slightly oversize KNS pins I was able to adjust the trigger to have less sear engagement and still have the trigger avoid doubling.

The idea of saving lower wear seems somewhat less important these days as the cost of lowers has dropped dramatically. I paid almost $200 for my first lower only 6-8 months ago but now I can get them for $70 or even less.

mif_slim
02-27-2011, 9:50 AM
People like the looks.?
Wow I think it's god awful ugly


Put rails on it and will be cool!

goodlookin1
02-27-2011, 11:36 AM
I have the Gen 2 Mod 2 KNS pins. Just got them. I never had a problem before with the standard DPMS FCG, however I just got a drop in Timney 4lb trigger, and i've read that it's a good idea to get some anti-walk pins as there is no spring retention holding the pins in place. Instead, you screw in two screws down into the receiver from on top of the FCG so as to apply pressure on the pins and keep them from walking out. Well, apparently those screws like to walk themselves back upwards and loosen up the pins, so I bought this set to keep that from happening.

It's not always mall ninjas that need them. I think they definitely have their uses, but for a standard FCG, i dont think theyre necessary. I never had any walk out on me. But now I also dont have any concern that it may ever happen, so peace of mind for $30.

YMMV.

Vanilla Gorilla
02-27-2011, 11:50 AM
oh no, they are tacticool, would not enter a mall without them

+1 lol all the other ninjas would laugh at you if you did :D

Charles4400
02-27-2011, 1:25 PM
I've had a pin start to walk out on a lower... didn't go out far enough to have an effect during shooting though, but definatley did start to creep out.

I only noticed it after I got back home to clean the rifle. Tapped it back in and chalked it up to me putting too much lube (few drops of slip 2000) on the FCG... Did not know there was a product which prevented this untill now.... I'm getting one for that rifle.

(nope wasn't shooting FA or bump firing or anything like that.... Just regular 5.56 (xm193)at a day at the range..probably around 250 rounds that day....)

Bryansix
02-27-2011, 3:10 PM
What does it mean when the pin walks out?

When I was in the Army I remember that we didn't do any maintenance at all on the lower besides wipe off the outside. I was also told that you could basically free swap lowers onto new uppers with little to no issues.

What was made very clear was that the components of the upper could not be swapped and only wear parts like the extractor pin or spring could or should be replaced if broken. Am I missing something?

RRichie09
02-27-2011, 3:38 PM
It means the pins start to come out of the holes.

As for upper parts. The only parts than can be readily swapped are the BCG and the CH. You may run into headspace problems when swapping BCG's between uppers but headspace doesn't seem to be a big issue anymore. As for the charging handle, swap away.

Bryansix
02-27-2011, 3:47 PM
BCG and CH? What are those? We called basic training issued glasses BCG's. Stood for Birth Control Glasses.

Cokebottle
02-27-2011, 3:57 PM
BCG and CH? What are those? We called basic training issued glasses BCG's. Stood for Birth Control Glasses.
Bolt Carrier Group and Charging Handle.

A charging handle is a charging handle and any of them will fit any upper (that is in spec).

The BCG is generally not a problem, but can get dicey on an upper with significant wear.

Headspacing is the critical dimension, which is determined by the distance from the bolt face to the taper in the chamber.
This is adjusted through the barrel's fitment in the barrel extension.

In general, on new-ish parts, you can swap bolts all day long and never have a problem, since the lugs in the barrel extension (and their mating with the lugs on the bolt) determines the position of the bolt face.

If you have a problem with excess headspace after swapping bolts, the lugs on either the barrel extension or the bolt are worn out of spec. In that case, a new bolt will be better than the old bolt.
If headspace is too tight after a swap, and the upper has always checked out fine, then the new bolt is not within spec.

If headspacing is out of spec, the proper solution is to remove the barrel from the upper and correct the fitment between the barrel and barrel extension. In practice? Chances are that the barrel is going to be "shot out" and keyholing badly before the lugs have that much wear.

MikeR
02-27-2011, 6:36 PM
I got mine when i somewhat knew better, i figured whats another $30 at this point. One thing is for sure, i wont ever have a problem with them walking or rotating.

I just wish magpul made them because they would cost half as much and get a whole other group of peoples panties all twisted up their whiny ***'. lol :shuriken: :p

slick_711
02-27-2011, 6:44 PM
Every time I see this thread title I read it in Arnie's voice. Thanks for that... :rolleyes:

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