Colt Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
759 Posts
Discussion Starter #1
So I bought this 1981 SP1 carbine end last year. Gorgeous, nimble, light and simple, and quite rare around here (Switzerland).



But it had this weird looking pivot pin





Instead of the normal two screws pin



At first I thought I needed to find an original pin. But then I started liking this device : the fit is perfect, it’s tight, and allows an instant disassembly of the upper and lower as was originally intended.

So now instead of replacing this by the original two screw, I am thinking of converting my other large pin Colt’s with this .... if I can find it.

It looks very similar to the pins used on HK weapons





But from my research the HK ones are smaller, both in length and diameter.

So I am looking for clues which weapon is using this, and if I can find a few.

Here are pictures and the dimensions in two standards

















 

·
Registered
Joined
·
414 Posts
That is not a Colt pin. It is an aftermarket pin.
Brownell's might still sell the original Colt pin you are missing. They could order one from Colt for you.
 

·
*** ColtForum MVP ***
Joined
·
14,657 Posts
I'm wanting to say that's an HK pin, but I'm not certain.
HK does use the same sort of locking pin in their rifles.

They may use the exact pin on their AR-15 type rifles and they do use them on their G3 types.

Go to Brownell's Schematics and look under HK.
There is a picture of this type of pin for the G36 rifle, part number 11.
Click on the red 11, then click on the picture of it lower on the page to expand it. It looks exactly like the pin you pictured above.

Gun Parts Corp also shows that type of pin for the HK G3 rifle, part 52......

https://www.gunpartscorp.com/gun-manufacturer/heckler-koch/rifles-hk/g3
 

·
Registered
Joined
·
759 Posts
Discussion Starter #4
I'm wanting to say that's an HK pin, but I'm not certain.
HK does use the same sort of locking pin in their rifles.

They may use the exact pin on their AR-15 type rifles and they do use them on their G3 types.

Go to Brownell's Schematics and look under HK.
There is a picture of this type of pin for the G36 rifle, part number 11.
Click on the red 11, then click on the picture of it lower on the page to expand it. It looks exactly like the pin you pictured above.

Gun Parts Corp also shows that type of pin for the HK G3 rifle, part 52......

https://www.gunpartscorp.com/gun-manufacturer/heckler-koch/rifles-hk/g3
Thanks

The issue I have is finding out dimension of the HK pins

When I found dimensions, they were smaller, like 6 mm diameter and shorter

But they do look very similar





I asked on the HKPro forum, but since my post was not about an HK weapon, it was deleted by mods I believe. Seems like quite a closed world there.
 

·
Registered
Joined
·
1,019 Posts


Here is a KNS Precision Inc. 0.315 inch diameter pin for the AR type large diameter which Colt used since the start of AR-15 SP1 until around in the US ban of 1994 to 2004.

The large diameter pin and it is also offset from the center of the military 0.250 inch diameter pivot pin to prevent just using a small hole bushing, since it is offset any military upper half M-16 could not be used.

This KNS pivot pins are the ones commonly used here in the US, I had seen many older AR with this pin type.

KNS also makes 0.250 inch dia. to fit current Colt and military spec AR types.

The Colt factory also made an pivot pin adapter for a large hole lower receiver to be mated to small hole military and modern upper receivers, I had used them factory pins and they are better than other brands of adapter pins in the market.

About the pin you have that looks like an HK pin, I agree it's an HK because I had a HK 94 pre ban 9mm carbine from 1989 to 2001.

The problem are those HK pins will have a different diameter size and length which won't work with AR pin dimensions.

Your HK pin type on your AR could probably made by German gunsmiths, they just copied the HK type but making a custom size pin to fit the AR.
 
  • Like
Reactions: CLASSIC12

·
Registered
Joined
·
759 Posts
Discussion Starter #6


Here is a KNS Precision Inc. 0.315 inch diameter pin for the AR type large diameter which Colt used since the start of AR-15 SP1 until around in the US ban of 1994 to 2004.

The large diameter pin and it is also offset from the center of the military 0.250 inch diameter pivot pin to prevent just using a small hole bushing, since it is offset any military upper half M-16 could not be used.

This KNS pivot pins are the ones commonly used here in the US, I had seen many older AR with this pin type.

KNS also makes 0.250 inch dia. to fit current Colt and military spec AR types.

The Colt factory also made an pivot pin adapter for a large hole lower receiver to be mated to small hole military and modern upper receivers, I had used them factory pins and they are better than other brands of adapter pins in the market.

About the pin you have that looks like an HK pin, I agree it's an HK because I had a HK 94 pre ban 9mm carbine from 1989 to 2001.

The problem are those HK pins will have a different diameter size and length which won't work with AR pin dimensions.

Your HK pin type on your AR could probably made by German gunsmiths, they just copied the HK type but making a custom size pin to fit the AR.
Thanks, I will buy a few KNS pins
 
1 - 7 of 7 Posts
Top