I just bought a used Unique DES/VO Rapid Fire pistol originally sold in 1978. It came with the extra mag and the original case and is in really nice shape. There is one thing odd however; the barrel has 8 vent holes, not the usual 4. The 4 nearest the chamber are similar in size to the holes on my VO79. The forward 2 are not tapped and the back 2 are tapped and plugged with slotted screws. But there are 4 more vent holes in front, none of them tapped and significantly smaller in diameter than the rear 4. There size is no bigger than and possibly not as big as a number 6 screw. They've been drilled so precisely that they look factory. The only thing that makes sense to me is because the barrel is about 6" long the extra vents are necessary to bleed off excess pressure. What do you guys think? Here are some pictures.
Nice examples Keith. In Canada at the time we only saw the VO70 and they all had the eight holes. All in aid of tuning the recoil impulse. I'd guess that the VO79 - quite definitely a different gun - reflected the experience of the engineers and decisions about the number of vents really needed.
i recently purchased a cased Unique VO 79 in 22 short with 2 mags. Condition very nice, what is something like this worth, as I couldn't find it in my blue book guide?