Anyone have an example of the OKT GI Contract ?
I know they have an OKT mark but anything else different?

This is really a great thread.  OP @RLR350 can we get an update on this and add a few things?  Like not using Photobucket... lol.

Anyhow, Colt 6 Holes also have a "birthmark", as was noted in the picture of the N1 Stock.  They have mold marks on the inside as seen here (just above the "L" (also seen in the 7th picture of the 1st post, very clearly);






Here are pics of an OKT (OK Tool and Die)












pics of the new H&R









Some overall pics, top to bottom - Colt, OKT, LSO, H&R





General observations of the H&R and OKT vs Colt.

Exterior:
1. Colt and H&R look almost identical on the exterior.  The holes on the H&R are not counter sunk as much as those on the Colt.  Both are similarly shiny, both have ribs that come to points (H&R is a bit more pointy though).
2. OKT is more mat on the exterior and the ribs are rounded at the ends.

Interior;
1. All 3 have "L" ribs that are the same.  All 3 use similar heat shields, though the colts I have (4 sets) have a mix of shields with wide tabs and skinny tabs.  Both the H&R and OKT seem to use the wide tabs.
2. Colt is the only one with the mold marks inside.  These are almost like an extra rib along the inside running parallel to the seams on each half.  OP's original post, picture 7 shows them well.

lol. I forgot about this place.

Back when I did this Photobucket was the way the sight worked.  I’ll see if I can do an update, but it looks like the above poster has it covered.  I’m on a phone and it’s hard to see everything.

Hope everyone is well.

If you still have the pics, switch them over to Imgur.

Photobucket stamps everything now. So the pics are kinda hard to see details with the photobucket watermarks.

But a great post you started!

I checked my photos and don’t have those anymore.  It looks like you guys have done a good job at recreating them.

As I said way back in 2010, many of the non Colt brands have similar features, but not all features.  Thankfully, some are even stamped with the manufacturer name or other identifying characteristic that automatically eliminates them from being Colts.  I think it is very rare that someone could find a pair of Colts and not be able to identify them using the existing photos in this thread.  As for non Colts, you will know they are not Colts, but may never be able to tell the original manufacturers in some cases.

It’s been years since I’ve looked at a pair, but if I recall correctly one of the features that wasn’t really reiterated anywhere past the OP is the “C” curve under the front mount.  It was shown in the sixth and seventh picture.  That photo could probably use a clear update if anyone has comparisons.

That “C” curve used to be something I looked for also, till I saw that the OKT’s had that same curve. I see that the H&R also has the curve too.

I really brought this thread back up because to me, it’s scary how much the new H&R and I suspect the Linemount 6 hole handguards resemble the shiny Colts of yesteryear. But as I noted, the one thing the colts have that the others don’t, the mold marks inside the body.   That tell tell is now my goto when I am verifying that a set is actually colt.

Thanks for seeing if you had the old photos.

@seand1111

Is the Colt birthmark you are referring to like the picture below? I just received Linemount latest batch of Retro handguards and the picture is it. If that's exactly what you are referring to as Colt birthmark, it is something that Taiwanese faithfully reproduced and sell by Linemount.

SHIT..... yes, only colts had this before.  I have a set of linemount's coming also, curious to see if this is present there also.  If so, they just made it super hard to tell colts from theirs via pics alone.

Since it was pointed out that the Linemount handguards also have the mold marks or "birthmarks" like the Colts.  I thought I would add a post here with pics to show the two.

While both look the same and have many of the same features, there are quite a few differences to tell them apart.

The main differences being weight, feel (surface texture), and a few additional features the Colts have that the Linemount's lack.  I will let the pictures speak for them selves now.

What a great bank of reference pics, thanks!

Although I kinda wish arfcom would resize them in the post so I don't have to scroll for eight minutes the next time I refresh 🤣

I recently bought a set of the Linemount handguards for an XM177E build. When dry fitting it, the rear portion of the handguard seemed a bit too thick to properly fit within the slip ring of the Brownells barrel I bought. I swapped the slip ring for a delta ring and proceeded to install th barrel. However, the Linemount handguards  still don't completely seat within the delta ring.  

Is this normal for the Linemount? What about the H&R?

All handguards of this type (clamshell) have various fitment quirks.

One thing I notice on both of your pictures is the handguards are not fully closed and aligned.  This could be part of the issue.

Edit.  I just took my Linemounts and tried them with a slip ring and a delta ring and they have a proud fit with each.  Looks like they could benefit from having some material removed from that end of the handguards.

and no, my H&R's fit fine with no material removed.  One set of my LSO's required a bit of material to be removed.  I can see that some of my Colts looks like they have had material removed, others not.

Thanks for the confirmation! Appreciate it!!

This is my experience too on one of my genuine Colt HG, some material was removed (not by me) to better fit the slip ring. So production variance existed back in the old days even with Colt OEM.