The Daisy V/L was one of the first modern weapons sold that utilized caseless ammunition. The oddity is that it wasn't a conventional firearm. Daisy Outdoor Products, which was at the time known as the Daisy/Heddon division of Victor Comptometer, had produced air guns in the United States since the late 1800s. In 1968, they began offering a 'hybrid' gun named the Daisy V/L (sometimes written just VL) after the initials of the Belgian engineer who invented it, Jules Van Langenhoven. The Daisy V/L came in two versions, a 'standard' version and a 'presentation-grade' version of higher quality (wood stock). A 'collector's kit' was sold with wall mounts and with the buyer or giftee's name engraved on a plate attached to the gun.
The V/L relied on the principle of adiabatic heating. Essentially, it was a lever-cocked compressed air gun - the user would work a lever on the bottom of the gun, and the mechanical advantage of the lever would compress a relatively powerful spring and piston. When the gun was fired, the spring would force the piston forward, compressing a quantity of air into the small space behind the pellet loaded into the chamber. In any normal airgun, this would cause the temperature of the air being compressed to rise by hundreds of degrees for the fraction of a second the air was at its maximum compression - then, as the pellet leaving the gun allowed the air to expand down the barrel, the air would cool back down to ambient temperature.
However, in the V/L, the 'pellet' was actually a .22 caliber bullet with a small cylinder of nitrocellulose-based propellant attached to the rear. When the piston compressed the air behind the pellet, the increase in heat would ignite this propellant - and that plus the compressed air would in turn fire the bullet out of the gun. Since there was no case, nothing needed to be ejected. Daisy, it seems, might have had ambitions to produce or license this technology in larger sporting or military weapons. However, there were problems.
The ammunition was derided as being very fragile, a common complaint with caseless ammunition and especially true with the V/L's rounds. Since the gun was single-shot, they were not protected by a box magazine, and the propellant cylinders could easily be snapped off the bullet if mishandled or could fail entirely if they were allowed to become damp. In addition, the gun is said to be fairly inaccurate as well, compared to 'regular' .22 firearms.
In the end, the Bureau of Alcohol Tobacco and Firearms ruled that the V/L was, in fact, a firearm (I'm not sure how Daisy thought it wasn't, to be honest) and that Daisy was not licensed to produce firearms. Rather than acquire such a license at that time, Daisy discontinued production and ceased selling the gun in 1969. Ammunition production also ceased.
These can be found on the open used market for between $100 and $350, depending on type and condition. One notable drag on their value is that ammunition is becoming scarcer as the original stocks are consumed, and it's not worth paying the asking price for the stuff if you're going to shoot the gun often - much like the Gyrojet. Although there are still sources on the Internet selling it in box or brick quantities (100/1000 rounds), eventually, the supply will dry up. It's an interesting collector's piece, however - likely more so in the presentation version, which had a wood rather than plastic construction. Only around 5000 were made with wood stocks (19000 with plastic) so that plus the historical curiosity may result in their value to collectors increasing as time goes by.
Much of the information in this writeup was taken from a story on the gun in Popular Mechanics magazine, (Oct. 1967, p. 120) and from the Gun Trader's Guide entry on the weapon. The rest is from various internet sources as well as talking with a Daisy V/L owner.
(IN 5 13/30)