I don't know if the handguard has been researched before, apologies if it has:

I'm making a Stargate SG-1 "Carter Special" rifle:
https://stargate.fandom.com/wiki/Micro_16_assault_rifle
https://www.imfdb.org/wiki/Stargate_SG-1_-_Season_7#.22Carter_Special.22_Micro_16_Carbine
(Note that the image watermarked "stargate6.com" is someone's clone, which has a different handguard.)

I've managed to get every single part (IYKYK) except for the handguard. I still don't know what it is. Whether or not I can actually find one is not the problem. I've only seen this handguard on the show; I've never seen another like it anywhere else. I want to at least find the correct make, model, part number, and maybe an old catalog listing before I give it up.

Here's all the evidence I've gathered for it: https://imgur.com/a/Bye7WwJ

The rumor is that it's Bushmaster. As I mention in the evidence album, some older Yankee Hill Machine handguards are close and apparently YMH was selling through Bushmaster in the 90's. If I had to guess, I'd say it was made to fit over a suppressor and could be ban-era LE/Govt Only. The show was made in Vancouver, Canada, so it could be Canadian-made for all I know.

Any Stargate fans, I'll throw you a bone on my other research: https://imgur.com/a/obmzhri

I might end up being the first person to eForm 1 an Olympic Arms Ultramatch. I'd like to get the handguard right so I can get the barrel length and OAL right for the Tax Stamp. Any help would be greatly appreciated!

Bookmarking for further discussion. The only reason I want a P-90 is because of Stargate. It’s actually fairly high on my purchase list

I strongly suspect that it was an older and longer YHM rail that was cut down.  That would explain the silver front.

But there were several cheaper rails with similar hole patterns.

Looks like something I bought from Model 1 Sales 20 years ago

Actually just finished SG1


Pretty confident that’s a chop job on the old YHM hand handguards and sans name nut.

Yea very close to YHM. Probably an older style.
https://www.model1sales.com/index.cfm?fuseaction=category.display&category_id=454

Here's a progress pic of my project rifle (I haven't really installed anything yet, just threw the parts together):

Stargate SG1 rules.