Grenade sleeve. It will only work with the Diemaco built M203 mount.

From what little I can find on the C8 with the thick profile, it seems to be a 16" barrel and appears that way in the pics.

I thought the C8FTHB = C8A2 (and that the C8A1 = C8FT) and that the HB portion just indicated that the barrel had a thicker profile in front of the FSB than the original C8 and C8A1 did, being more similar to the M4 profile.  This is the weapon depicted on the Colt Canada website as the C8A2.  The weapon with the thick profile in front of the FSB is the SFW, which does have a 16" barrel.  Does the C8FTHB actually = the SFW?  Can someone clear this up?

It's suppose to a be 15.8" barrel. They did that so it can't be sold on the US civie market.

The C8FTHB is the SFW. It's the only carbine to pass the NATO SFW trials. The Colt M4 failed. The SAS are currently using it. It's call the L119A1. The Brit's have a solid FSB so they can run the HK AG-36.

The C8A2 is a carbine spec out by the Danish Army. Most of the LE agency in Canada use a semi-auto version.

The C8A3 is suppose to come on line in the CF. It's just a FTHB upper on the current C8 lowers.

SFW?

Special Forces Weapon ?

The C8SFW is a C8FTHB (Flat top heavy barrel) with a KAC RAS installed.  Obviously only the best of the best are deserving of a real rail.  

The C8A3 is already in service and is just a C8FTHB with a triad, ambi controls and green furniture.  All models are marked accordingly.  

That thicker portion is called the simon sleeve, it slides onto the barrel and accomplishes two things.  First it enables the use of Diemaco's god awful M203 mount which adds 2 1/2 pounds to the M203 and makes it sit way too low, it is quick detach though.  Second it gives the barrel the proper diameter to mount your bayonet but due to the increased barrel length a much smaller portion sticks out past the muzzle.  

The C8FTHB, A3 etc is a more compact package than a C7A2 but due to the fact that it uses a heavy barrel is actually heavier than a C7A2.  This is the sort of stupidity that results when a weapons technician is put in charge of weapons procurement instead of the combat arms.  Given the choice I'd take the transition model shown at the top of the first KevinB pic.  We got them first issued in Afghanistan in 2003 and it's a C8 with the original 14.5" light barrel profile with a flat top weaver rail upper, the one in the pic has the Elcan scope but they originally came with the EoTech 552.  These were marked as C8 but then again so was the C7 when they came out with weaver uppers, these should be considered C8A1 and C7A1.  Not sure what happened to these as I haven't seen one since.

ETA:  My knowledge is limited to CF configurations and I have no idea what names Diemaco puts on their overseas models.

Okay so is this the nomenclature as the Canadian Forces understand it?

(CF designation - commercial nomenclature):
C8 - C8
C8A1 - C8FT
C8A2 - C8FTHB
C8A3 - SFW

I went back using archive.org to the old Diemaco website and I obviously had some things wrong in the notes that I have (I think I only did the Diemaco/Colt Canada portion of my chart after the sale to Colt).  Firstly the C8FTHB and the SFW share the same barrel profile, but the FTHB is 14.5" and the SFW is 16".  Colt Canada sells something now as the C8A2, but this clearly doesn't have the same barrel profile (from the picture on their website it looks like yet another variation on the prototype M4 barrels).  

Also, it appears that the use of a larger profile under the hand guards on the C8 probably precluded it from using the regular M203 mount, so Diemaco had to develop its own mount.  The M203 mount is designed to attach at the rear to an A1 profile barrel (this was also one of the reasons for the government profile barrel used on the A2).

Not quite, I've tried to clear it up below:

C8 - C8
C8A1 is a flat top with the original 14.5" barrel but receivers are still marked C8, very few of these seem to exist and may have been pulled from service for upgrades?  Originally issued with EOtech 552
C8FTHB is marked, wait for it..... C8FTHB.  This has the 15.9" heavy barrel with black furniture and Elcan C79 sight (black cover).  Some have been "upgraded" with ambi controls and Triad mounts.
C8A3 is basically a C8FTHB that comes with the ambi upgrades and Triad mount from the factory.  It features a green CAR fiberlite style stock that is unique to Diemaco.  Cover on the Elcan is green as is the rest of the furniture, handguards are still original 6 hole CAR style but painted green.  Interesting to note that Canada still uses the CAR type tightening nut on the buffer tube instead of the newer notched style.  Receivers are marked C8A3.
C8SFW, I haven't seen one in person but I imagine that they're marked C8SFW, only difference between a C8FTHB and the C8SFW is that it comes with a KAC RAS installed at the factory.

So there are the C8s in use by the CF.  Don't go off the website as Diemaco will build whatever you want and may refer to it as the same thing, unlike Colt who attach a specific model No. to each variation.  All Canadian rifles have Weaver rails on the upper receiver, including the newer C8FTHB (I believe) yet the Triad mount uses Picattinny.  Why new rifles don't come with Picattinny uppers is beyond me, makes trying to mount your own optic very frustrating depending on the mount.

The reason for the Simon sleeve?  Simple, we only ever used to issue M203s to units going overseas in the lated 90s (Bosnia).  These were original US style M203s IIRC they were made in Florida?  Anyway, the powers that be decided that loosening a few screws with an Allen key to remove them was something that only a weapons technician was allowed to do.  So everytime you had to send them to then next unit the Weapons techs (only a couple per Battallion) would have to remove them all, box them up and send them to the next unit to do all over again.  Obviously a time consuming process, so the fellow in charge of procurement (a weapons tech), had Diemaco whip up a quick detach mount so that the soldier issued the M203 could mount it himself.  The front mount is just behind the FSB on the C7 on the large flange immediately behind the handguard retainer.  So when they made the new C8 barrels they had to come up with a way to attach them without modifying the mount, the only solution was to increase the diameter of the barrel.  The really awesome part of all this is that well before they did all this the CF finally ponied up all the cash so that the infantry battallions got two M203s permanently issued per section (squad) so the whole quick detach thing isn't really necessary anymore.  Also because of the weight of the new C8s (heavier than a C7) and the weight of the M203 (2 1/2 more pounds over stock M203) hardly anybody mounts one on a C8 anyway, who wants to hump a 15lb carbine?.  Actually, I don't think that most NCOs even know that you can mount an M203 to the C8.

Thanks for all the info.


SFWs have 16" barrels and all other C8s (with the possible exception of the C8CT) that have been made by Diemaco or Colt Canada are 14.5".  If the C8FTHBs that the Canadian Forces have now have the 16" barrel, then I would guess these were a special run for them.  Here is the archived page for the Diemaco C8FTHB, which says that it has a "0.36 m" barrel (which translates to ~14.1 inches, which would just not include the muzzle device).  The archived page for the SFW notes the 16.1 inch barrel length.  Now its also clear from the pictures posted that the CF understands the C8FTHB to have the 16 inch barrel length (as the weapons are marked as such).

The SFW did also have the KAC RAS installed at the factory, as did the SFSW that Diemaco offered (which bundled in a bipod and other accessories).  I think Diemaco stopped offering the Special Forces Support Weapon even before they were bought out completely by Colt.

The guy on the right is carrying the orginal M203 the CF had. I know the Strats(Armoured) have some in their lock up.

This is the new POS CF M203 weighs 2 1/2 pounds heavier. I was always told they went to this design because some egghead engineer at Diemaco was worried we were going to have cook offs. But duh the US Armed Forces I don't think has ever had one cook off ever....

So the non-stylized D K forge code uppers are not Diemaco? What does the non-stylized D forge code stand for?

TBH, I'm a little disappointed that nobody has made a push to get back to using the muzzle to launch grenades...

A bullet-trap style grenade could give everybody with an M16/M4/C7/C8/ETC the ability to launch grenades without needing anything special.

Have been told by the guy at SAW they were aftermarket A1 replacement uppers.

The C8A3, the SFW, and FTHB are all the same base gun with the same 16" barrel.  The accessories are what changes the nomenclature.

The C8A2 is like an M4 with a step cut 14.5" barrel and a picatinny flattop.

The C8A1 is a weaver flattop with a skinny 14.5"  barrel.

The C8 is the fixed handled upper with fields sights and a skinny 14.5" barrel.

Does anyone have a picture of a C8 flat top receiver with the Weaver rail?

Not according to Diemaco they weren't.  Look at the archived Diemaco pages.  In addition, by 2004, Diemaco had updated its page where it clearly said that the C8A2 = C8FTHB, but oddly enough, the C8A2 it advertised had the step-cut barrel not the heavy front profile barrel.


They both have a step cut, but the profiles are not the same.  The C8A2 cut is far closer to the FSB than that of the M4.  This is no doubt because of the difference in the Colt and Colt Canada/Diemaco M203 mounts.  From the picture RebelRouser posted of it, it showed it attaching to the barrel much closer to the FSB than with the standard Colt mount.

Also, by 2004, Diemaco offered its weapons with either the Weaver or MIL-STD-1913 upper.  This is something Colt Canada still offers.

Page 2. I have the sales brochures I got from Diemaco, but I don't know if they will scan.

Thatguy96, I really don't know what to tell you.  I'm in the army and I have used these weapon systems quite a bit.  I really don't care what Diemaco calls something on their website, I've relayed what the Canadian Forces has stamped on their weapons.  Diemaco would build you a weaver flatop with 18" heavy barrel, carbine gas with a UTG rail and stamp it C8SFW if you wanted it for your army.  So let me try this one more time, the C8FTHB, C8A3, C8SFW as issued to the Canadian Forces all have the longer 15.9" heavy barrel with Simon sleeve.  This is supposed to be the retro forum so I thought I'd share some pics of the C8.  Didn't really think it was going to turn into a discussion of all things Diemaco.

ScottRyan, can't acount for the differences in the M4 profiles since the Diemaco M203 won't fit.  It has to have the much larger diameter present on the Simon sleeve to work.  Like I said Diemaco will build whatever you want and perhaps that barrel met another nations requirement.  Rest assured that if you wanted a C8A2 that used the US M203 they'd build it.  They're also marketing their own 40mm design these days that looks very similar to the HK 40mm launcher.

Who wanted pics of the Weaver rail?  Look at the pics RebelRouser posted, those are all CF weapons and therefore have the Weaver rails.  We adopted a flatop long before the U.S. so picatinny didn't exist yet.  Weaver is basically the same but the slots are more narrow, this means that some 1913 mounts won't work with weaver but weaver mounts work with 1913 rails.

ETA:  Hey, I know that guy in the desert cam in the last photo.  He's been promoted since that pic.

I don't have a problem with it turning into this discussion.  Its good information.  Like I said first off, clearly Diemaco and the CF had a different interpretation of the FTHB, which I found interesting.  The pics you posted clearly showed a 16" (15.9") weapon with the heavy front profile barrel.  All I was trying to point out was that there is this disconnect and subsequent confusion.  Knowing this prevents confusion in the future, at least to some degree.  There's a reason why my notes have sections for factory nomenclature and military nomenclature, because they often do not match.  I wasn't trying to disagree with you, just pointing out more pieces of the puzzle.

I know the two step cut barrels are not the same profile between the C8A2 and the M4.

I think the C8A2 = C8FTHB thing is a typo or some other error.

By the time the C8A2 term appeared, they had stopped offering the 14.5" heavy front profile barrel as a standard option.  Someone could easily have made the error when they looked and said "Well, the A2's barrel is heavier than that of the A1."  What I'm seeing is very reminiscent of issues surrounding the CAR-15 term or Colt's 700 series.  I could easily see the CF getting a specific configuration and having Diemaco build them on lowers marked FTHB.  They did get bought by Colt hehe.  To reiterate, I don't think anyone's wrong.

A year or so ago I looked high and low on the web for dimensions on that cut but never did find it.  Seems to be about 1/2 as close to the FSB and about 1/2 as deep as the M4 cut but without the slopped angle.

In this thread, KevinB posted the C8HBFT is the same as the SFW but without the RAS.  http://www.ar15.com/forums/topic.html?b=3&f=12&t=223495&page=6

Which is exactly what I've been saying.  Had I known the interest their was going to be in all the variations I would have taken more photos as we had the C8, C8FTHB and C8A3 all issued in my platoon.  When I return to work after leave I'll attempt to take some photos but it was unclear of those rifles were returning to the unit or going elsewhere.

Did you see the Canadian upper for sale in the EE? Sorry, don't have a link, but it looked nice. (Flattop though)

Hey Leg! Are you back yet? Where's the photos?  I really liked this thread and appreciate all the info and pics from everybody (Rebel Rouser too).  Please get us a shot of the barrel with "Simon Sleeve" from the front sight forward?  Next Build? Retro? Maybe not but who else on AR15.com would care about this? 4 pages and counting.

In case anyone is interested
http://www.ar15.com/forums/topic.html?b=3&f=127&t=528752

Work is pretty busy at the moment but I'll try and take my camera in a snap a couple o pics.  Apparently all of our C8s followed us home but I found out that we just turned 40 of them in and only have seven left in the company.  Hopefully their are still C8FTHB and C8A3 marked lowers so you guys can see the differences between the two.  Might have to start a new topic in discussions though since they are definitely not retro.

Meh, we're the ones who are interested.  At least link it from this thread.

OMG they exist.  I'm sorry now I got rid of my 3 C7 uppers a couple of years ago.  Welcome home Leg.

Welcome back LEG!  Looking forward to your pics and info.