WTK: Colt 635 9mm auto sear question

[Steve Combat Ventures LLC]

I’m an 07/02 looking to convert a current production Harrington & Richardson (Colt 635 clone) to a post-86 dealer sample.

I know the M16 FCG is the same as the 5.56 counterpart, but I have been getting mixed information on the auto sear. Is it also the same part or is it a different part than the 5.56 version? Curious because the bolts are different.
 

Thanks in advance.

Steve Ou

Combat Ventures LLC in Texas

07/02

 

 

[MPFiveO]

The USGI auto sear is exactly the same. Wondering where you're getting conflicting information. The only things to be concerned with on the 635 are the buffer weight and the distance the bolt travels past the bolt catch. You don't want the bolt slamming into the catch or it can break it off. There are a number of buffers that will work but the right one to use is the Colt 2 piece 9mm buffer.

[Steve Combat Ventures LLC]

Thank you for the information on the sear.

 

This is a factory H&R 9mm “pistol” so I’m not sure if the distance the bolt travels past the bolt catch would be an issue once I make it select fire versus its current semi automatic configuration? If so, I guess I need to figure out how to remedy or check it.

[MPFiveO]

As a pistol it's set up to run whatever buffer they use, which may work fine for semi auto but may not provide the proper timing to prevent bolt bounce in full auto. Different buffers vary in length so if you have to swap buffers you'll need to check the length of travel. I cannot tell you if the factory buffer will work or not once converted to full auto.

[Grasshopper]

Hi Steve Combat,

Don't forget.  The factory hammer & trigger pins were a different material for the Colt 9's from the factory.  They are often referred to as "stainless" as they are not blued like the pins in a 16.  Not sure what they are really made of but it was the intention to prevent breaking of hammer pins.  KNS pins work well also.

Good Luck,

YMMV,

Grasshopper

[Steve Combat Ventures LLC]

16 hours ago, MPFiveO said:

As a pistol it's set up to run whatever buffer they use, which may work fine for semi auto but may not provide the proper timing to prevent bolt bounce in full auto. Different buffers vary in length so if you have to swap buffers you'll need to check the length of travel. I cannot tell you if the factory buffer will work or not once converted to full auto.

Thanks I sourced the 9mm Colt SMG buffer, at least I think I did?

 

https://www.gandrtactical.com/Colt-9mm-SMG-Buffer-Assembly_p_314.html

[Steve Combat Ventures LLC]

15 hours ago, Grasshopper said:

Hi Steve Combat,

Don't forget.  The factory hammer & trigger pins were a different material for the Colt 9's from the factory.  They are often referred to as "stainless" as they are not blued like the pins in a 16.  Not sure what they are really made of but it was the intention to prevent breaking of hammer pins.  KNS pins work well also.

Good Luck,

YMMV,

Grasshopper

Good info thanks KNS is local!

[MPFiveO]

1 hour ago, Steve Combat Ventures LLC said:

Thanks I sourced the 9mm Colt SMG buffer, at least I think I did?

 

https://www.gandrtactical.com/Colt-9mm-SMG-Buffer-Assembly_p_314.html

That looks like the correct buffer. Also the stainless FCG pins can be procured from Liemohn Manufacturing in Kent, WA. Tom is a top tier expert on all things Colt 9mm SMG. He manufactures DOE clones as well as other models. Contact him if you have any troubleshooting issues.

[Steve Combat Ventures LLC]

6 hours ago, MPFiveO said:

That looks like the correct buffer. Also the stainless FCG pins can be procured from Liemohn Manufacturing in Kent, WA. Tom is a top tier expert on all things Colt 9mm SMG. He manufactures DOE clones as well as other models. Contact him if you have any troubleshooting issues.

Thanks I just emailed Tom! 

[Got Uzi]

Here’s the recipe for a successful Colt 9mm SMG:

 

Kyn-Shot 9mm HD hydraulic buffer

5.56 carbine buffer spring (no spacer)

carbine buffer tube

KNS pins 

 

Set the gun up like this and it’ll run great. Been doing it for years with no issues at all and no broken parts. 

[Steve Combat Ventures LLC]

16 hours ago, Got Uzi said:

Here’s the recipe for a successful Colt 9mm SMG:

 

Kyn-Shot 9mm HD hydraulic buffer

5.56 carbine buffer spring (no spacer)

carbine buffer tube

KNS pins 

 

Set the gun up like this and it’ll run great. Been doing it for years with no issues at all and no broken parts. 

thank you for the advice  the host gun is a factory H&R (Palmetto ?) 635 9mm 10.5" pistol. i figure i'd be modifying the lower (sear pocket and sear pin hole), add the M16 FCG (and sear), the Colt 9mm buffer (or KynShot), and KNS pins. im not sure what buffer spring H&R is running out of the factory so i'll have to take a look and also see if there is a spacer in there. and I believe they have a carbine receiver extension on it already but if not i can change that.

[Got Uzi]

Don’t waste your time with the Colt buffer. Also make sure you have a ramped bolt or the trigger will feel like a jackhammer on your finger.