OK, in the beginning there were straight prong Vortices, like the ones in Mongo's pic. They are called Vortex because of the offsets on the INTERIOR of the tines. Look at Mongo's first pic for a clue. They worked really really well esp considering the competition available in the late 80's. The only problem they had was the couter rotation created by the propellant gasses eventualy loosened them. This was a bigger concern with the shorter barrels. Much Loc-Tite and torque was needed to keep them in place.
Smith Enterprises (SE) changed the design to incorporate helical flutes that off set the counter rotation. The helical flute model worked very very well and didn't come loose. They worked so well that SE couldn't keep up with demand. SE changed the design slightly to increase production. I've always called this design change the "straight flute" model because the cuts don't appear to curve around the circumference of the FS.
On this changed model the flutes are just cut at an angle to the bore line. The manufacturing change caused the prongs to be undercut at their base. There are the models that failed. SE claimed faulty heat treat on them but after checking several new ones against several known good ones the only difference found was the undercut tines.
Here's a close up from a recently posted pic showing the undercuts.
Photo courtesy of M4A2_LO73754 of FIN
There was also a FS called the Brennan Nil-Flash. It looked somewhat like the Vortex but wasn't as aesthetic being just a cylinder with 4 internally curved prongs and straight flutes. Many of these were modified to look more like Vortices by shortening them and turning a groove into the ends. There was no way to modify the prongs so they still lack the triangular profiles used on the Vortex.
Originally Posted by mach6:
the mushrooming issues have been discussed ad infinitum. Furthermore, they are issues from the pst -- the distant past and were limited to a very small lot as discussed above. I have several of the latest model G6A2 types, and their variants to include the G6A2 5.56mm, the limited production G6A2 6.5mmG/6.8mm and the very new "Direct Connect" (DC) Vortex for use on the (EBR-14) M-14. A few versions for the M249 and M240 as well. None of these have mushroomed or shown any signs of fatigue after many, many thousands of rounds. In part, this should not be suprising since the surface hardness of the G6A2 is RC 58-60 (!) with a core hardness pushing RC 40. Tough enough for you. I know, because I saw the physical testing results at ARDEC last year.
Interestingly enough, but not entirely germane to this thread, the G6A2 M249 actually improves group size. BTW, the systemjust became available with an extremely robust BFA that works on the M-4 & M16 as well (USG only).
As an aside, I wish these forums had more in the way of technical discussions from people who use M-15-related components in their official capacity. DCD Ft. Benning used to have such a discussion board but it is no longer up. Too bad. Still, it is interesting, although frankly anecdotal to hear the observations of consumers at the retail level -- but only that. Every once in a while though, a forum contributor comes up with an observation that Force Developers/Modernizers can actually appreciate. An believe me -- they, we are listening.
When you use these items every day in real life siutations, these matters take on an entitrely different tone. Somehow commentary on how "cool" or "bad" something looks, without a critical discourse on on the technical merits is amusing at best to troops on the line.
Originally Posted by mongo001:
Originally Posted By Zaphod:
I've never seen a straight Vortex.
Can't say that no more. Old style with straight tines.
Orinally Posted by thebeekeeper1:
I have three (or four?) of these--I obtained them from Olympic Arms about ten years ago. They have no name on them to indicate who the mfr. was. The tines are definitely straight and there is NO flash whatsoever--none, even in complete darkness. They are amazing. I was at an AR15.com shoot where three of the four tines cracked and broke off of another guy's Vortex. So far, no problem with any of mine.
Originally Posted by raf:
From the manufacturer's web site, linked above:
"The Vortex incorporates a helix design essentially tightening itself when the weapon is fired and helps align exiting barrel gas to improve accuracy with all bullet types.
- "Left Hand" slots for left hand threads
- "Right Hand" slots for right hand threads
Flash suppression is not effected with straight slot muzzle devices."