Open up the items and look down the barrels. The ones designed to fire blanks have blocked barrels, exactly as the poster in OPs post implied. Flashes and such are added later if needed.
i bought some blank .223 rounds from that same company you referenced, military grade blanks. Great quality, btw...i use them to launch golf balls 300 yards using my AR-15
Hijacking top comment for relevant information. Take a look at Movie Quality Prop Guns.
https://www.westernstageprops.com/Blank-Guns-and-Prop-Replicas-for-Movies-and-Theater-s/1821.htm
Open up the items and look down the barrels. The ones designed to fire blanks have blocked barrels, exactly as the poster in OPs post implied. Flashes and such are added later if needed.
Direct image link from website: https://cdn3.volusion.com/jodua.csmpx/v/vspfiles/photos/SG38-4T.jpg
I've also used a blank firing gun before on a cattle ranch. Its barrel was blocked. It only made the sound, recoiled, and cycled.
i bought some blank .223 rounds from that same company you referenced, military grade blanks. Great quality, btw...i use them to launch golf balls 300 yards using my AR-15