KAC M4 RAS with odd numbers?

[hanschien]

I got a used set of KAC M4 RAS on another site's EE. The guy had good feedback and was upfront in his post that it's a RAS with odd numbers or he thought was maybe a RIS.

From my internet research:

RIS = odd numbers + clamp by FSB
RAS = even numbers + clamp by upper receiver

It came with the "SAS" bottom half which also has a clamp like the top half.


TL;DR: Did I get a hybrid RIS/RAS? :confused:

[SilverCat]

I just pulled out my RAS and it's rail markings are even. RAS' have a little metal springy piece at the front that slides into the handguard cap, and a screw tightened clamp that fits under the delta ring and around the gas tube at the rear.
I'm not quite sure what an SAS bottom half is though??

Does the rail have any amount of wiggle or play when it is in place?

[hanschien]

I just pulled out my RAS and it's rail markings are even. RAS' have a little metal springy piece at the front that slides into the handguard cap, and a screw tightened clamp that fits under the delta ring and around the gas tube at the rear.
I'm not quite sure what an SAS bottom half is though??

Does the rail have any amount of wiggle or play when it is in place?

Both the top and bottom locks up tight! I'm not doubting the authenticity, just a curious query with the odd numbering.

[SilverCat]

I don't think that an RAS has ever been produced with odd markings. Would you mind uploading a picture of the rail?

[Iraqgunz]

http://quarterbore.com/kac/kacrisras.html

http://looserounds.com/2013/10/16/kac-ris-and-ras/

https://www.m4carbine.net/showthread.php?49163-KAC-RAS-real-or-fake

[SilverCat]

If you read into the m4carbine thread it mentions something about a navy contract RAS with odd markings going backwards down the rail, but I have no idea whether this is real or not.

[hanschien]

I'll post pics when I remove the rail. I remember that the date was in '09 with cage code.

Edit: original post
http://www.ar15.com/forums/t_7_159/1403587_.html

[kwilkin]

I'll post pics when I remove the rail. I remember that the date was in '09 with cage code.

Edit: original post
http://www.ar15.com/forums/t_7_159/1403587_.html

Interesting. It looks like a RAS (with the clamp at the delta ring) but with RIS markings (odd numbers, counting down toward the muzzle). I wonder if this was a blem?

Either way, it looks to be legit KAC all around. Not to mention, the UK/SAS lower rail retails for about $100 new. I would say you have an interesting piece and got it for a great price.

You can always email KAC and see what they say.

ETA:
It looks like you got the Canadian version, as seen at Operation Parts:
http://www.operationparts.com/kac-knights-armament-ras-m4-canadian-with-uk-sas-lower-rail/

If it bothers you, I have a new US KAC RAS that I will trade you (PM if interested), otherwise I would hold onto it.