Extended Length Fire Control Pins, KNS Precision

Reader Michael sent me an email telling me about KNS Precision’s extended length fire control pins. They are designed to work with the Kaiser US Polymer Lower which has the same dimensions as the AR180B. These could also be used in your original AR180B lower.

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I ordered myself a set along with some sideplates and they look like the cat’s meow. I could not be happier with the fit and finish. They are the perfect length. Range report to follow. FYI this gun ran flawlessly with the Colt 901 pins during my last range trip.

It has a new nickname, Thumper. Anyone who has shot a 5.56 SBR under cover at the range can probably relate.



KNS sent my order out very quickly. I ordered it on 3-16 while out of town and when I got home this morning it was already waiting for me. Top notch service.

If you are on the fence about building a Nodak NDS-18S, I think this is the last piece of the puzzle.

Lower Parts Kits are still available for $125 shipped (PayPal slightly higher). Just send me an email. Rick@ar180s.com


Extended Length Fire Control Pins

One of the items that I do not offer in my 180B lower parts kits is the extended length fire control pins. Armalite is no longer making them and I have suggested using standard AR15 pins. This has been met with some skepticism.

The AR180B lower was made from a polymer and to increase the strength it was made thicker and therefore the pins need to be longer as well. The AR15 pins in an aluminum Nodak NDS-18S lower end up have the same amount of engagement as in the AR15 lower, about .100″ per side.

A new reader raised concerns and suggested longer pins that are used for another gun, the Colt 901. I asked around on several forums and believe it or not, the guys at the Smith and Wesson forum came through. They use these pins in the polymer lower of a 15-22 and they work great. They measured some up and with that info I ordered a couple sets to test.

I ordered a set of Geissele 901 Replacement Pins and I have to say, they are going to work just fine.

Lets look at the three different pins and compare.

AR15 pin on top .900″

Geissele 901 pin in the middle 1.000″

AR180B pin on the bottom 1.125″

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Here is my NDS-18S lower with original pins

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And finally the NDS-18S with Colt Geissele 901 pins


They do not sit flush with the sides but have over .150″ engagement on each side, a 50% improvement over using AR15 pins.

For those interested in a 180B lower parts kit, I have another batch ready to ship. Send me an email at rick@ar180s.com and I can get it shipped out to you. $125 shipped per kit or $130 if you use PayPal, goods and services only please.

I am also going through my personal collection and I will be liquidating some of my duplicate items. Let me know what you are looking for and maybe something can find a new home with you.



SAR West Gun Show

I just got back into town from Vegas about 12:30 this morning and I am preparing to head to Phoenix for the SAR West gun show. I have never attended this show and I hope to get the most out of it. I will be wandering around with my AR-180S Shorty and a backpack full of AR-180B Lower Parts Kits. I’ll be stopping by the NoDak booth to check out his retro stuff and I am hoping he has some NDS-18S lowers with him. (Ok, I’m hoping he has one in particular, the one I ordered some months back.) I’m also hoping to run into Bill, a great gunbroker seller who I have purchased some AR-180 parts from before.

Make sure you say “Hi” if you see me walk by.

The best part however is going to be staying with Chuck and Shirley and all the other guests at their house. I can’t wait to meet all the great folks.

Sleep has been a little lacking for me this week and I don’t see that trend changing anytime soon.



Navigating Armalite.com

I’ve gotten quite a few folks emailing me to ask how to find parts on Armalite.com.

They still have some AR-180B parts and many are on clearance. There won’t be any more once these are gone.

The best advice I can give you is to look in your manual and find the part number for the part you want and search for that. The break down can be found on pages 8 – 12.


Your second option is to do a search for 180B. That brings up many parts but will leave you somewhat lacking when you consider that some parts used on these guns are actually AR15 parts.

Armalite re-configured their site a few months back and there are no longer direct links on the homepage to the 180B parts. They are still there if you know how to search.

AR180B Parts & Accessories

Now some other interesting information can be gathered from looking at the manual, the part numbers are in three different formats. This gives us a clue as to their origin.

Parts with a four digit number are the same as Original AR-180 Parts. They may or may not have been left over stock but they are a direct replacement.

2641 Operating Rod

Parts with an eight digit number are 180B only parts.

1882000 Front Sight Base

Finally parts with six digits and are prefaced with letters are AR15 parts that were used on the 180B.

EU0190 Front Sling Swivel

So there you go. Get them while they last, or at least before I buy them all.



New E-Mail Address and a Cool Tool on GunLab

In addition to coughing up the cash to renew my domain and my wordpress subscription, I also added a new email address.


You should all be getting your correspondence from me there (if I did it right).

Feel free to drop me a line there if you want to share your AR-180 information and if you have any questions.

If you are not already a subscriber, please drop your email in the box on the right and you should get added to my list.

Chuck at GunLab.net has just put up an article about a cool fixture used to machine the cam slot in the bolt carriers of early AR-18’s.

Go give him a read. I admire the skill of the tool and die makers that built these guns. True masters and a skill that this country is loosing.


Thanks again to all those who have purchased the AR180 Lower Parts Kits. The small profit from the sale of these helps keep this site running.