I was wondering if anyone had info or knew about High Standard riot shot guns. It is  20-6  K1200 and it does not have a serial number. It does have a winchester trench gun stlye barrel shroud and bayonet lug . I believe it was either a prison or police gun.

High Standard made very good utility-grade pump and auto shotguns for many years.
"Back in the day", some police departments bought HS guns.

High Standard marketed many of their shotguns under the Supermatic and Flite King names.

Here's a link to a site that has HS owner's manuals:
www.stevespages.com/page7b.htm

While the K-1200 isn't listed, the same general gun was made under a number of model numbers.

Here's a site with exploded views:
www.again.net/~steve/page7a.htm
This may help you decide which model is most like yours.

Here's Gun Parts Corporation's site.  They sell HS parts:
www.e-gunparts.com/

Thanks, why no serial number?  I am trying to approx. the age. I guess maybe before 1968?

Before the 1968 Gun Control law, firearms weren't required to have serial numbers, and a lot of shotguns and .22 rifles didn't.

The Flite King models, of which yours is one, were made from 1960 to 1966 with a "Riot" model being made until 1975.

On the standard Flite King pump, HS was not in the shotgun business that long but seemed to have police sales longer, with the ill-fated semi-auto Model 10-A and 10-B Bullpup made longer.

Since your gun appears to have no serial (are you SURE, look good), I would assume it was made in the 1960 to '66 production time.

Defenitly no serial Number, checked the entire reciever, the only thing is on the barrel where its says Riot 20-6 K-1200 (I assume 20" barrel 6 shot). do you know if they ever put the trench gun style shroud and bayonet adpter? or do you think someone added it, I removed it to get the barrel info and the front bead site was trimmed down so the shroud would fit . I looked at one of the links and it listed a K120, I think that is the gun, it shows different barrels including mine.

I'm fairly sure the shroud and bayonet latch are after market.

Thanks for all the info, you know your stuff!

try this site,

www.histandard.info/

very good info here,

search the forum, he has a few riot questions answered,

i have an 18-7 RS.   K-120 (not 1200)
the serial # is very small just over the safety on the left side,