Tround for oil well drilling


Back in the 1970s and early 1980s, I was in the oil business in West Texas. I went to a lot of industry trade shows, and at one of them, there was a display in which was featured a drilling method which involved an automatic-loading system that used a Tround-like cartridge which fired three ceramic bullets at a time into the hard rock ahead of the drill bit. This apparently was intended to increase the drilling penetration rate by breaking up the rock ahead of the drill bit. I even had a dummy sample of this Tround. I have no idea as to where this sample is now, but it was plastic, 2 or 3 inches long, maybe an inch across, and I remember the ceramic bullets as being about .30 caliber. Does anyone know about this drilling system and whatever happened to it?



From SLICS 2008 a display


Dennis–We had another thread on this subject a few months ago. If you go to the following and scroll down there is a diagram of the device that uses this round.



But does anyone know if this system was ever used or is still in use? I haven’t had anything to do with the oil industry (except for buying gasoline) for about 25 years, and haven’t kept up on drilling technology.

That one trade show (which I think was in Dallas about 1981 or 82) was the only time I ever saw this. They had a model of the firing device which was set just above the drill bit on the bottom of the drill string. It was basically a repeating gun and it held a magazine with large number of the cartridges, but the details escape me. I don’t know how firing was controlled from the surface, but it must have been quite a neat trick to do so. With all the heat, pressure, shock, and vibration at the cutting face, the firing device would have to be extremely rugged to operate for long under such conditions. I can’t imagine that it could have been very successful.


Harry’s photos of my 2008 display are above & covered the rock drilling. My accompanying book had this to say:

179 Of clear molded Lexan plastic, this .25 Cal. Dardick Triplex Tround Rock drilling dummy has a struck brass primer, in a copper washed steel holder, which is probably a #209 CCI manufactured shot shell primer. This primer is held in a brass base insert. With a side label proclaiming this a ‘SIMULATED TROUND” it shows three, .25 caliber white ceramic bullets set at a slight outward angle.

180-181-182-183 David Dardick, Tround International Inc. has developed, along with the help of Dresser Industries, a drill bit that fires ceramic bullets so as to pre-fracture, hard rock
formations at the drill face, still allowing a somewhat conventional drill to work at the same time. Initial testing found this method to be from 200 to 400 percent faster through hard rock formations, and in side-by-side
testing the Tround bit showed little wear when compared to the conventional bit. An added benefit is that seismic signal measurement is easily accomplished.
The prototype drill bit was loaded with 500 salvos, with the commercial bid holding 5000 salvos. Working on the open chamber principle, a sensor fires the gun when hard formations are encountered.
These are .25 Cal. Dardick Triplex Tround Rock drilling variations, and a 47.2 grain ceramic projectile. All show a 2-piece case, a copper primer in a copper washed steel battery cup, and three ceramic bullets. We assume the case color variations may pertain to a certain load strength, but are not sure.

Hope this is of help


The one I had was a simulated Tround with a transparent body, and also some simulated propellant. I don’t remember it being marked as such, but perhaps it was. If this approach could indeed produce the alleged 200 to 400 percent rate improvement reliably, it would have been wildly successful. As I haven’t heard of its use in drilling, then or now, I can only assume it was never accepted for some reason. Drilling rig time is horrendously expensive, and anything that will speed up the drilling process even a little could be economically worthwhile.

Another Tround story - back in the aftermath of 9/11 I had involvement on a Federal panel debating the arming of airline pilots (Flight Deck Officers). One of the issues was the weapon, and a concern at that time was possible theft of the weapon and subsequent mis-use. That led to a discussion of the merits of having a unique weapon-cartridge system, so that if a weapon went missing, there would be no ammunition commercially available that could be used in it, and vice-versa. I put forth several ideas as to how that could be accomplished, one of which was to revive the Dardick pistol and the Tround, possibly in an odd caliber, such as a .42. Of course, none of those ideas ever went anywhere, but of all of the supposed gun experts present, I was surprised that no one else had ever heard of the Dardick.


Hi DennisK
I got this info from a trade journal reprint by Dardick.
It was for “hard rock” only usage that it was apparently so successful. Not knowing spit about rock drilling I’d assume it was a very expensive thing to buy & then feed as it had a limited “magazine”, & needed to be pulled up for re-loading (as I recall?). Then to be used for only a relatively small percentage of total drilling time, and then only for a limited amount of holes.
That said I guess that’s why it was not even a little bit successful.
As I said, I don’t know spit about drilling holes in mother earth, & just a WA guess on my part.


Wow. I would totally believe that none of them had ever heard of the SPIW project. And, perhaps gyrojets. But the Dardick??? Really?
I mean, they showed, and fired, a Dardick tround pistol on the History Channel in the late 90’s on that ‘Tales of the Gun’ show. I would assume that those guys at least watch a little television every once in a while.