Colt Mag-Na-Port Pistol


by R.K. Campbell

photography by R.K. Campbell

June 12th, 2010




Not long ago I embarked upon an experiment that involved firing several hundred +P cartridges in the .45 ACP. I did so both for my own satisfaction and as an experiment to be included in an upcoming book on the 1911 pistol. I have always felt that standard 230 grain ball loads were just fine for personal defense, but that if we could have a reliable hollow point bullet we should go with it.

I approached the +P with disdain. After all, how much could be improved with the .45? Range and power are not the same. A pistol is possessed of short range killing power. A +P load that gives the cartridge an extra 100 fps in velocity may increase the effective range 25 yards or so but do we really need this edge? The value of a +P load may be that the velocity is sufficiently increased that we may enjoy good expansion from a jacketed hollow point bullet. With this in mind, I collected several good hollow point loads and proceeded to test them in various 1911 type handguns.

Before we proceed, let's consider recoil. Recoil is best expressed using a power factor. The powder factor that governs pistol competition is also useful in demonstrating handgun recoil. Let’s look at the table below:

Ammunition Velocity Power Factor
Black Hills 230-grain Ball 850 fps 195
Black Hills 230-grain JHP 870 fps 200
Black Hills 230-grain JHP +P 920 fps 212
Winchester 185-grain Silvertip 945 fps 175
Cor-Bon 185-grain JHP +P 1140 fps 210

It is worth increasing recoil in order to achieve greater velocity? Apparently many believe so, as +P loads are very popular. I conducted my own experiments, firing into wet newsprint, gelatin and other material. The +P loads are indeed impressive. Some are very reliable and accurate. They all kick more than standard pressure loads. In a steel frame handgun a practiced shot may handle the increased recoil, although we may ask why? Among the great modifiers of recoil is the porting process known as Mag-Na-Port. Often associated with Magnum handguns, I decided to have one of my 1911 handguns Mag-Na-Ported. The pistol is a well proven Series 80 Colt 1991 A1 pistol.

The ports turned out very well. The physics are well known, but the performance is another matter. Just what did the ports achieve? In a word, a lot. I was prepared for a certain velocity loss that did not materialize. Velocity loss was no more than 11 to 20 feet per second with a given load compared to previous test figures, which is actually a standard of deviation between lots and statistically irrelevant.  Unlike the oversize barrel ports popular a few years ago, the Mag-Na-Port gets the job done without significant velocity loss. As for control, the percentage of control gained is another matter. I estimate the ports reduce muzzle flip by ten to fifteen per cent when using +P ammunition. The increase in control is less proportionately when using a mild load such as the standard 230 gr./850 fps hardball load. If you are wishing to use +P loads in the .45 ACP Mag-Na-Ports are an excellent option. Accuracy was unaffected by the ports, although we did see a slight long term improvement in accuracy. I will put this down to greater control and less involuntary muscle contraction during test firing. The Colt is not the most accurate of 1911 handguns, but a good solid product of Yankee manufacturing and a pistol that you can bet the farm on. This is a good handgun. 

With Mag-Na-Ports, Colt quality, and a good +P load, the Colt is ready to take on bad men and bad beasts without hesitation. While we have not completed the test program, there are a number of stand-out loads. The Cor Bon 185 grain +P is a good load, accurate, reliable, and a worthy successor to the old Super Vel load. Of course, Super Vel did not have the punch this one does. They did set the pace, however. This load features a bullet that expands or fragments in test media and offers a good choice at high velocity.

The Black Hills 230 grain +P would be the preferred load for animal defense. This load was once advertised as the Mack Truck of .45 ACP loads. The comparison is an apt one. This load exhibits an ideal balance between penetration and expansion.

As a final addition, we fitted the Colt with Herrett’s Oval grips. These grips are smooth, allowing good hand fit and rapid adjustment. The palm swell - the grips are not classic 1911 flat - is a good trick that allows the shooter to maintain good but comfortable control in firing heavy loads. They are eye catching and functional, all we may ask. During the test period all of our raters commented on how well the grips fit their hand.

We added Metalform magazines to ensure reliability. When using +P loads, it is not uncommon for slide velocity to outstrip the ability of the magazine to feed properly. Quality magazines are a great aid in reliability.

Overall, the test program was illuminating. While we are still studying +P loads, the two standout loads are set aside for specific use. The Mag-Na-Port option is proven. Colt was proven long ago but it is nice to reaffirm our beliefs. Herrett’s stocks are old line reliable but the modern Oval grips a nice addition to the line. 

More to come. 

R.K. Campbell


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Click pictures for a larger version.


A good reliable Colt pistol and Mag-Na-Ports makes for an effective personal defense combination.



The Mag-Na-Port process is conservative but quite effective. With Magnum pressure the ports will prove more effective, but even with the .45 ACP they worked well.



The ports cut through barrel and slide in a very uniform, clean manner. This is a class act that aids in controlling heavy recoil.



This is a typical ten yard group fired with the Colt and Cor Bon +P loads. This will save your life!