Cor Bon Thunder Ranch Ammunition


by R.K. Campbell

photography by R.K. Campbell

January 23rd, 2009




Cor Bon is no stranger to most of us in the shooting field. Cor Bon has been the first with the most for over a decade. Many years ago civilians serious about personal defense had far less choice in defensive ammunition. Those who favored any number of the excellent 9mm handguns available could take their pick of standard pressure fare from the big three. For the most part, this was a 115 grain JHP at 1150 to 1180 fps.  Those in the know often used one of two much more potent handloads. We often used these even in duty handguns. Another track that some of us took - and with twenty years passed I suppose we can admit to this - was to carefully pull the service load in a Quinetics bullet puller and save the brass and bullet. A heavy charge of powder, usually 7 grains of Herco, was substituted for the factory load. The result was jolting the factory bullet from 1175 fps all the way to 1350 fps. This load was fully equal to any of the later +P+ loads. An acquaintance fired about 500 of these in his Smith and Wesson Model 59 over a year's time or so. The front dust cover of his pistol broke off! In any case we also used the two ‘standard’ handloads. One jolted the Speer 125 grain JSP to about  1250 fps. A load I considered superior was wrapped around the Sierra JHP and Herco powder for 1350 fps. The Sierra bullet is not only very accurate, it opens up well and fragments upon meeting flesh and blood. Several of my comrades who were limited to the 9mm but able to choose their own loads used this handload. Any difference in effect between a 115 gr./1350 fps 9mm load and the factory 110 grain .357 Magnum load would be purely conversational.

The Smith and Wesson 5906 proved capable of handling these loads better, although another acquaintance lost this ambidextrous safety lever after 200 rounds of handloads. Remember, the 9mm was a very poor performer with most loads and we were desperate for something better. When Cor Bon legitimized the Sierra bullet load those of us in the know were grateful. As a bonus, Cor Bon has access to ballistic labs and had capabilities handloads could only dream of. Their loads are as fast as the old heavy handloads but with far less pressure. 

Recently I was able to test and evaluate a new line of ammunition from Cor Bon. These are Thunder Ranch trademarked loads. Clint Smith is a well known writer and a person of wide shooting experience. Folks who have established a commercial enterprise like to have their personal emblem embossed on hats, jackets, and the like. Thunder Ranch has earned a good reputation and become something of an icon. Clint Smith close Cor Bon loads as a trademark and for sale in the Thunder Ranch Pro Shop. The Thunder Ranch loading is available in 9mm, .40 and .45 caliber. I was able to test all three loads in nine different handguns. I test fired the 9mm in three handguns. The results are as follows for velocity in the 9mm--

Walther P1 1203 fps
Smith and Wesson M&P 1219 fps
ArmaLite AR 24 1240 fps

These loads use the Barnes X bullet. This is an all copper design offering exceptional performance. The nose is softer than the base, offering good expansion, but the bullet retains its integrity and will not expand past the base. As a result the balance of expansion and penetration is excellent, favoring penetration. Accuracy potential is excellent due to the long bearing surface. Accuracy testing for five shot groups at twenty five years, in 9mm, follows--

9mm 115 gr. DPX

Walther P1 4.0 inches
Smith and Wesson M&P 3.5 inches
ArmaLite AR 24 2.0 inches

These loads fed, functioned and fired as designed with nothing left to be desired in accuracy. 

In .40 caliber I have but one handgun, the Beretta Centurion. Results were good, with a 140 grain bullet jolted to 1180 fps.

Beretta .40 3.25 inches

In .45 caliber I had five handguns to test the loads in so I had to carefully ration the .45 ACP loads. I don think there is anything to be desired in performance of the .45 ACP DPX load. Accuracy is good and control is also good, a product of the lighter than standard bullet. But the 185 grain bullet penetrates as much or more than the average 230 grain JHP. 

.45 Velocity, 185 gr. DPX

Colt Defender, 3 inch barrel 950 fps
Smith and Wesson 1911 PD, 4.25 inch barrel 1040 fps
Smith and Wesson 1911, 5 inch barrel 1073 fps
SIG GSR, 5 inch barrel 1090 fps
Springfield long slide, 6 inch barrel 1125 fps

.45 Select Accuracy 25 yards

SW 1911 PD 3.6 inches
SIG GSR 2.0 inches
Springfield Long Slide 1.9 inches

During the test program there were no failures to feed, chamber fire or eject. That is all we can ask for. The Thunder Ranch loads are a good addition to our defensive battery.

R.K. Campbell

Editor's Note:

This Thunder Ranch ammo is the same tried and trusted Cor-Bon DPX ammo that they have sold for years, using the Barnes XPB loaded to the same velocities. I carry this ammo, and rely upon it myself. By introducing this Thunder Ranch line, Cor-Bon is putting Clint Smith's endorsement upon this excellent ammunition. To quote Cor-Bon's website:

"The Elite would class Thunder RanchTM Training center has teamed up with distinctive reputation of CORŽBON, to exclusively bring you Thunder Ranch Defensive Ammunition. Made specifically and Packaged for the world renowed defensive tactics trainer, Clint Smith. Thunder Ranch Ammo offers the same qulity and performance your'vecome to expect from CORŽBON's DPX Ammunition. Clint Smith Has put his respected reputation and trust in CORŽBON to provide his students the best shooting ammunition in the industry, PERIOD!"

Jeff Quinn


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Click pictures for a larger version.


The Cor Bon Thunder Ranch DPX loads are superlative defense loads, with a combination of accuracy potential, penetration and expansion.



The DPX bullet is among the most impressive bullets ever introduced, with good performance in all calibers.



Compared to a conventional hollow point, the DPX is impressive. The Cor Bon .45 caliber DPX bullets on the right were fired from both long and short barrel 1911s. Expansion is impressive even from the short barrel.



The Beretta Centurion in .40 caliber proved accurate and capable. The DPX loading is appropriate for this handgun.