Welp, I'm *this* close to being done, except for minor 601-type details like the rear sight wheel... and a couple more serious issues.

(edit: fixed the title, not sure how I lost nearly an entire word there)

Looking at an Airsoft build for details of the front sight (see below for more on that), and lo and behold, I have Learned A Thing.


(Image from Sturmgewehr sale thread in 2020)

The handguards had extra vents on the bottom, which no one had posted pictures of before (or I managed to miss them, always possible). They seem doable, I guess... I don't suppose anyone has measurements?  Or even a nice high-resolution picture taken straight on at the bottom?

As for the sight, I've gotten rather nervous about my ability to braze that thing on without damaging my slickside upper. Quick, to the John Thomas-mobile!

And just as quick, a response. "Sorry, not doing these any more." (I can see why, custom work and he's already stacked with pin-and-welds, FSB pinning and everything else.) Question is, is there anyone else who might be able to do this? (I've read the Cloning The LaFrance article, and would rather have the correct-ish brazed front tube.)(The Airsoft dude did his with epoxy, but I rather suspect there's a slight difference in recoil between 6mm BBs and 5.56mm out of an 8.5" barrel.)

At least the 601-ish N-23 is down to just the same minor details, and the rather more simple handguards build...

Love that gun.
Thanks for bringing this to the Retros attention.
I never realized the lower side of the handguards had those two rows of slots instead of the normal scallops. Plus the round hole in the front.
Maybe it was there for access to something as it was being built?

The front hole is not round, its the stock first hole in a standard length HG from which these were cut I believe.

Thanks for the observation.
So, if my visual exam is correct, the front oval 'hole' is each side of the handguards is the last hole of the triangle handguards 'normal' bottom vents, and the two rows of elongated 'holes' are added. I don't have a set handy to see if the were added specifically between internal ribs. But they look to be more than one size in the length component.
History is rather detailed.
To the OG, I'd love to see how your build progressed.
I've got a pretty screwed up upper I might try the silver solder business after I practice a bit.

I put together a LaFrance inspired SMG 9mm, but machined a front sight to bolt in the carry handle. I have, however, used low temp aluminum welding rods to fill in engraving and to add material to new lowers so I can machine the A1 profile at the buffer threads. I would try it if I made a proper LaFrance sight. It melts at 700 degrees so a propane torch could be used.

Low temp rods at Harbor Freight

Just remember the solder will dissolve if you try to anodize the part.

Didn't know there was a market for the old straight Vortec flash suppressors

Mine's a 601(-ish) build, so repro duckbill all the way.

Found a straight-on pic of the bottom of the left HG, although a little lower-res than I'd like.



By way of ultra-high tech image/reality comparison techniques (zooming in on the image until it was life-size, and holding my handguard up to the screen), the vents are between the third rivet boss and second rib from the back (short), second rib and second rivet boss (long), second boss/first rib (short) and first rib/first boss (long). Might be able to eyeball the dimensions, then it's drill press and dremel/hand-sanding time.

In looking for some tools that wandered off (have to run out and pick up some drill bits and locking forceps later), I also found a random length of aluminium tube that fits quite nicely at the front of the sight channel - way too long, way too thin, but it does give me the outside diameter, anyway. Not sure how to kludge the actual aperture part together and aligned - kind of thinking using my cheapo 4x "retro" carry-handle scope and a laser boresighter. Once the scope's sighted in, then I can adjust the rear sight for the dot, and figure the vertical offset for the front aperture to match the dot, or where the POI should be in relation to the dot.

Oh, and let's not forget the shimming needed to assure level sight alignment - it's not going to be all that adjustable, vertically.

Gee, I wonder why I was hoping to find someone to do it for me...

Great builds

@MRW

How are you holding the handguard cap in place?

Hah! More digging has produced this image:



Which might be from John Thomas' build - it was from an archived thread here, so the poster's name is missing.

Followed by finding this one:



Which, while not a higher res, is from an actual LaFrance example and should be usable to figure out the dimensions of the vent holes. (Also shows that my beater triangles with the gap will be authentic. )

I'll probably still chop the Linemount repros for pretty-pretty display/glamour shots, though.

Ask him. Lafrance was still alive when I emailed him last year. A little Internet sleuthing gave me his email. He was friendly

You guys are killing me!

I are an idiot. All this time I've been worried about doing that front sight as a one-shot-gotta-be-perfect-the-first-try thing. (I only have the two slickside uppers, and didn't want to mutilate one figuring it out.)

Except... I completely forgot that I have the top 2/3rds of a carry handle that someone had chopped to homebrew a flat-top. (Bought it for the A1 sights, which turned out to be pristine and appeared to still have the factory oil on 'em.)

And to make it even *more* embarrassing, I only remembered that after casually wondering if I could snag a couple of beater detachable carry handles to use as testbeds.

Brain no worky.

There is a guy named Booligan in the 3D printing space who built a version of the M16K.

He designed a 3D printable sight for his that uses the carry handle mount.

It might help some folks out who aren't looking to mod their uppers.

https://odysee.com/@BooliganCustomGunworks:f/M16K-Carry-Handle-Front-Sight:5

That is way cool!

I emailed him. He does not sell parts, is why he released and said feel free to print.

I don't have a 3D printer.. do any of my retro comrades I have one and would be willing? If so please IM me

Message BigRix or Red_McCloud, if anyone can help you it would be them.

Hmmm….  I have some LaFrance handguards kicking around somewhere with the front handguard cap.  It will be a couple of weeks before I’m back home but I’ll try and remember to grab some photos for you.

Awesome, I've been slugging around recently and not getting anything done, so maybe that'll get me off my ass.

I hadn’t seen this thread earlier so apologies for the month long delay in responding; have you tried downloading the part and sending the model to one of those commercial printing firms, like Sculpteo, Hubs, etc.?

So I checked the sight on Sculpteo's website and it would cost only about 13$ total to get it printed out of PA12 nylon, although Sculpteo has a mandatory 30$ order cost so it would be good to grab it and a variety of other parts attached, if one so chooses.
Still, very nice of Booligan to release that file!

Why not make a better version.

Like say an aluminum square post with ears that holds a A1 sight.  It is welded to the front of the Upper on the flat area behind the slip ring.

You can then. Adjust for height.