Any real-deal pics floating around of supressed (not moderators) M16s from the 60s-early 70s?

These are two I've saved (robbed) from other sources. I really like the suppressed M16 in the top pic - which is likely a Mk4 ModO, since they are SEALs. From what I understand, the suppressor slipped over the barrel, but that doesn't make total sense to me in this pic. I am building my 605 clone with an eye to adding a suppressor later as a result.

The pics in the real deal thread also have suppressed sniper rifles that are similiar. I really like the first pic - I have no idea which of the 3 or more types used either of these are. I wish someone who really knows could ID them for us and give us more info.

Thanks Morg...........any others out there?

Quoted: Thanks Morg...........any others out there?

Scrounged these up from my collection of over 14k photos.

Those ATF pics make the Baby Jesus cry...

The large diameter suppressors that start at the front sight base are Human Engineering Laboratories (HEL) M4 suppressors.  It is permanently attached to the weapon.

The suppressor that is skinny and starts further out towards the distal end of the barrel is the MAW-A1 suppressor made by Sionics.

Were the 601 bbls cut down?

I'm doing a supressed sniper clone. Looks like I may need a 605 bbl?

ETA: are those old supressors still available?

Quoted: Were the 601 bbls cut down? I'm doing a supressed sniper clone. Looks like I may need a 605 bbl? ETA: are those old supressors still available?

The barrels were not cut down.  The HEL slipped over the barrel and then threaded onto the existing barrel threads.  Then the suppressor was marked concentric to the bore, holes were counterbored and threaded by the front sight base and screws were used to tension the suppressor while maintaining concentricity.  An extra gas relief hole had to be added to the bolt carrier to handle the increased pressure.

Without the HEL, the M16 with the modified carrier would not work.  Also, an HEL added to an unmodified M16 could result in potentially deadly failure.

The Sionics suppressor only required removal of the flash suppressor and could be used on any weapon.

The HELs were never on the NFA registry to my knowledge, except for samples possibly at Reed Knight's collection.

Sionic suppressors were commercially available and are still seen from time to time, but are inefficient compared to modern offerings.  Had a guy offer me one that had a bunch of full-auto fired through it.  He was asking $600.  I passed.