Thursday, October 04, 2007





Corbon 9mm 100-grain "PowRball" +P and Browning Mk III Hi Power

By Stephen Camp

Visually similar to the Glaser Safety Slug, Corbon's PowRball is an entirely different round. It weighs 20-grains more, but retains the round nose profile for reliable feeding. It is a +P round and has an advertised velocity of 1475 ft/sec.

This round should feed reliably in any 9mm that will feed ball and externally is very similar to the Glaser Safety Slug. It's said to react very consistently in 10% ballistic gelatin regardless of barriers before striking the gelatin.

Using a Browning 9mm Mk III with factory barrel, I tested this round for accuracy at two distances as well as for expansion. Chronograph data is based on a 10-shot average fired 10' from the chronograph screens.

100-grain 9mm PowRball

Average Velocity: 1473 ft/sec

Extreme Spread: 49

Standard Deviation: 17

High Velocity: 1494

Low Velocity: 1445

At 15 yards, I fired a group, slow-fire, to see how it would group from the Hi Power. I also fired a 5 shot group with Corbon's 125-grain +P JHP for comparison. Point of aim was the inner sphere. I also fired 5 sets of controlled pairs at 10 yards with the PowRball. Both targets are displayed. The controlled pairs were fired as quickly as I could obtain a "flash sight picture" while using a two-hand hold and Weaver stance.

It should not necessarily be inferred that the PowRball is a better grouping load than the 125-grain Corbon JHP, although that's what happened in this instance. The spread in the latter is probably due to me, not the ammunition nor the Hi Power; it was the first group I fired. The "important" thing is to note that the PowRball at its higher velocity and lower bullet weight does hit a little bit lower. As most defensive scenarios will be closer than 15 yards, this divergence of POI to POA is probably moot. As the 5 sets of controlled pairs show, the ammunition is easy to handle from the Hi Power.

When fired into water, the PowRball shed its jacket every time. Water will make this happen more than gelatin as the fluid more easily gets between the lead bullet and the jacket. I recovered the expanded PowRball bullet and jacket fragments shown on the left side of the picture and those on the right from another shot. The bullet was not recovered as it completely penetrated the last jug of water! The expanded PowRball in the middle was recovered after "scientific mud expansion" testing. The recovered bullet and fragments on the left weighed 94.5-grains. The expanded bullet measured 0.59 X 0.64." Believe it or not, the PowRball recovered from the "scientific mud" weighed about 75-grains even with the dirt particles on it.

Though not "bad," the felt recoil on the 100-grain PowRball was "sharper" than that of the 125-grain Corbon +P JHP. To me, the felt recoil of the PowRball and the 115-grain JHP are about the same. This is not surprising as the velocities are very similar.

From the same Mk III

Corbon 115-grain JHP +P: 1411 ft/sec

Corbon 100-grain PowRball +P: 1473

Corbon 125-grain JHP +P: 1258

Folks who do the serious gelatin testing report that the PowRball averages about 12" penetration in 10% ballistic gelatin and does so consistently, regardless of barriers.

Though the Mk III in the background reliably feeds about any JHP I've tried, the PowRball has both a rounded ogive and LOA that mimics FMJ. Shown with a Corbon 125-grain JHP, most would agree that the PowR ball would be more likely to feed well in a wider number of 9mm pistols.

With its "ball" profile, this PowRball should have no trouble in negotiating this Hi Power's feed ramp. For self-defense, a handgun's reliability is paramount. You get it with the PowRball and a cartridge capable of being put exactly where you want it should the rare need for a very precise "rescue shot" be necessary.

I was favorably impressed with the PowRball for a personal protection round for the private citizen. I would do some testing before using it myself, but I believe that it would make a potent 9mm load. In "scientific" terms, it has quite a bit of "whammy" and with decent placement, should "stop" a felon about as quickly as any commonly used defensive round and perhaps, quicker.

The 9mm 100-grain PowRball grouped well and was more consistent shot to shot than their .45 ACP, 165-grain PowRball that I tested several months ago. Both rounds feed reliably.

From a 5" 1911, it had an average velocity of 1220 ft/sec, but an extreme spread of 119, which resulted in a standard deviation of 40.

This 165-grain Corbon PowRball expanded well in water testing and was both reliable and accurate, but did not prove as consistent in standard deviation as did the 9mm version. The .45 ACP PowRball was the first caliber Corbon released this design in. More calibers are to follow.

For those concerned about feed reliability with a defensive load as well as over-penetration, the PowRball is a very viable choice. Both the 9mm and .45 ACP versions penetrate approximately 12" of ballistic gelatin and should remain inside the average human torso assuming a solid hit. Both "passed" the dreaded "4 Layers of Denim" testing routinely done by those seriously studying terminal ballistics and bullet performance.

I think it will be a winner and might make a viable choice for those wanting the same performance under a wide number of conditions, but who are unable to obtain or use several of the law enforcement only loads.