In most cases, the military requirements for a sidearm differ from that of the private citizen's. With the soldier, the pistol is usually a secondary weapon if he has one at all. The private citizen will be using it as the primary and possibly only weapon at his disposal in "the dark place." While both the soldier and the private citizen might be attacked without any warning, the citizen will usually be at arm's length or so from his aggressor while the soldier's enemy might be a hundred yards distant. To me, this suggests that in most cases, the citizen's response must be quicker and at least initially without taking cover if unexpectedly subject to violent attack.
The military pistol need only feed ball or FMJ rounds (unless one is being used by certain SOG's in situations against people not deemed "soldiers") while the citizen's pistol will be expected to work reliably with about any kind of ammo the guy can buy. The soldier's sidearm need not be concealed in most cases while exactly the opposite remains true for the civilian carrier. Again, we're fortunate that the Hi Power can be pretty easily concealed for the size handgun it is.
Neither needs to be capable of formal competition accuracy, but both do need to be "accurate enough for their intended mission" as has often been stated. I'm glad that in good examples, the Hi Power is usually capable of better accuracy than most shooters can wring out of it. Both must be reliable and the Hi Power is…with one caveat.
This 25-yard group was fired with a Mk III 9mm Hi Power using the factory barrel and Remington 115-gr. JHP +P. It was fired from a seated position and in slow-fire. This is likely more accuracy than required for most of our needs, be they real or perceived.
The older "classic" Hi Powers were intended to work with FMJ ammunition as used by their first "employers," the military. These pistols are the ones made prior to the FN Mk II pistols and have the "humped" feed ramps that worked great with ball, but so-so with some JHP's and no-no with others!
Hi Powers made from the Mk II forward work fine with most JHP ammunition that I've tried that weighs from 115 to 124 grains and while my testing is limited with the heavier bullets, the guns have worked just fine with the 147-gr. slugs. If your Hi Power is pre-Mk II, you may have feeding problems with some of the blunter, shorter JHP ammo used today. You can either use ammunition having a rounded bullet profile as exhibited by Federal's 115-grain JHP, both standard and +P version, or Remington's 115-grain JHP, also available in standard pressure and +P. If you want to use something else, but the reliability is just not there, you can have a competent gunsmith "throat" the feed ramp on your Hi Power. This is not difficult, but must be done right.
This is the Browning Mk II 9mm pistol. It is the first commercially available Hi Power to be sold having extended ambidextrous thumb safety levers and is quickly identified by its narrow "rib" running the full length of the slide. The front sight is not serrated from the factory and is integral to the rib. Though still somewhat small, the fixed sights on this version are more usable at speed than those on earlier Hi Powers. (The right-side safety lever for left-handed shooters has been removed on this particular pistol and it has a C&S ring hammer and aftermarket grips.)
These guns are the first I'm aware of that came with the non-humped feed ramps straight from the factory.
As has been the case with the Mk III Hi Power, these pistols have proven extremely reliable with a very wide array of JHP ammunition.
The Mk III has fixed sights which are larger than those on the Mk II and both are dovetailed to the slide. The ejection port has been enlarged, but is actually beefed up a bit at the lower rear to prevent slides cracking when used heavily. Like the Mk II and the classics made in the '70's, it has the spur hammer. The Mk III pistols sold in the US have internal firing pin safeties not present on the classics or the early Mk II pistols.
For lots of shooting or defensive use, the Mk III is my first choice.
Even though my eyes are not what they used to be, I find that the sights on the Mk II or Mk III pistols work fine and I have no trouble with them when practicing quick, defensive types of shooting. I do find the older Hi Power's fixed sights to be a bit lacking although OK for slow deliberate fire. I find that I do no better or worse with the very popular Novak fixed sights when compared to the factory Mk III sights in slow or rapid fire work. While the defensive Hi Power does require "good" sights in my opinion, I find that the factory sights are plenty "good" enough. On the other hand, there is utterly nothing wrong with having a set of Novak or Heine sights installed on your Hi Power. Just be sure that they are "on" for you. Though I've not yet tried them, Novak's new adjustable rear sight looks to be a very viable option for the Hi Power shooter preferring to be able to change his sights to exactly match various loads. Of the adjustable sights I've tried, those from MMC are likely the strongest, but I've seen Bomars used on a couple of 1911s under other than range conditions and they held up fine. In general though, fixed sights are the most popular for defense guns, including the Hi Power.
What I'm getting at is that the defensive Hi Power requires sights that can be seen at speed. I do not care for the "express" sights that have some following these days. I personally found them no faster than conventional high-visibility sights and more difficult to get precise hits with. This might be of no import if on a derringer or even a small snub where most expectations are only for close, coarse accuracy, but the Hi Power is capable of so much more that I do not recommend the use of "express" sights. I have been asked about rear sights having the large "ghost ring" aperture, but have not tried it so I cannot comment. If you opt for night sights, you'll get no argument from me. I still prefer plain black on black sights, but if shooting in extremely dim light, the night sights do make getting good hits easier. If you opt to use them, understand that their life span is about 12 years or so.
I find the extended thumb safety necessary on the Hi Power, but do not on the 1911. The small classic thumb safety lever is just too small for best work at speed in my experience and some are pretty stiff as well. I prefer the FN factory extended thumb safety to the others I've tried, but don't care for ambidextrous safeties on the Hi Power. The reason is simple. I have large hands and have on occasion accidentally engaged the safety in the middle of a rapid-fire string! Other folks report no such problems, but be aware that it can happen and determine if you're prone to it or not. I remove the right-side thumb safety lever and reshape the shaft it was mounted on. Cylinder & Slide does offer extended ambidextrous and single-side safeties for folks not liking the factory version. Any should fit any version of the Hi Power as well as the clones, but it will probably need to be fitted by a gunsmith.
Probably the most controversial issue in the defensive Hi Power modifications is removal of the magazine disconnect. Sometimes called "magazine safety," this device prevents the firing of a chambered round if the magazine is removed. In short, the pistol cannot be fired with the magazine removed. (Actually, it can if you apply pressure to the trigger sufficient to keep the lifter firmly against the sear lever before dropping the magazine, but this is too risky to recommend under the stress of a life or death situation.) The magazine disconnect is pushed into a hole in the rear of the trigger when the magazine is inserted and the pad area of the "safety" actually moves upward against the front of the magazine when the trigger's being pressed. It contributes to a poor trigger in most cases and one that's heavier than the same pistol without it.
Here you can see the magazine disconnect and spring as they would be removed from the rear of the Hi Power trigger. The small pin (with detent in it) that is visible on the rear of the trigger would be removed. It would be each individual shooter's decision whether or not to remove the magazine disconnect.
I routinely remove the magazine disconnect from all of my Hi Power pistols not only to help get a good trigger pull, but also to allow the magazine to drop free when released and to be able to fire the weapon without a magazine in place if necessary. This makes the pistol no more "unsafe" than the slew of 1911's on the market, HK's, Glocks, SIG-Sauers, and so forth. Opponents caution that such a removal of a safety device might be used against you in the inevitable civil suit that follows any shooting, justified or not. So far, I have not seen one documented case of this where the complainant prevailed if the shooting itself was intended and the trigger purposely pressed. I do think it could cost the owner of such a pistol if the shooting was unintentional. An example would be kids getting hold of the pistol and thinking it was safe because they'd removed the magazine and then negligently shooting themselves or another. In any event, there are gunsmiths who can put good trigger pulls on the Hi Power with or without the magazine "safety."
You decide what's best for your own unique situation.
While speaking of trigger pulls, I'd suggest that you stay in the 4.5 to even 5.5-lb. range. A good gunsmith can provide this and I've found that "crisp" and clean breaking is more important than "light" for the defensive handgun and this includes the Hi Power. Like all single-action semiautos, the Hi Power does not "tolerate" improper gun handling and under stress, the errant finger on the trigger might be pressing just a little too hard. You get the idea. My "carry Hi Powers" have triggers of about 4.5-lbs. or so.
The gun should be comfortable and if you have the free choice to choose the Hi Power, you probably already feel that it is. I cannot stand the factory checkered nylon grips with thumbrests that come from the factory on the Mk III pistols. The stocks themselves are fine and provide a secure grip, but I don't find them comfortable. If you do, they're fine. Most people seem to prefer aftermarket grips for their Hi Powers. I cannot tell you which is best for you, as this must be decided by you. I can say that I prefer Craig Spegel's checkered grips to any that I've tried. I also like the much less costly black checkered rubber copies offered by Butler Creek. They are thicker. Having had my Hi Power (and other handguns) out in rain or in extreme heat, I do find that the checkered grips provide a more secure grip when the hand is wet. Pachmayr offers checkered rubber grips for the Hi Power that also provide checkered covering of both the front and rear grip straps and Hogue offers a version that has finger grooves in the front strap area. Probably the thinnest grip on the market is from Navridex, but I've not personally tried them and some people speak highly of grips made by Ahrends. Pick the one that works best for you.
Also in the area of comfort is the problem of hammer bite. Many of us are smacked by rear of the spur hammer or the bottom rear of the factory ring hammer when firing the Hi Power, especially if we've drawn the gun with a high grip. In the picture to the right, I bobbed the hammer spur of the top pistol at the second lateral serration. This solved the problem for me and does for others as well.
Other options such as dishing out the shank of the hammer at the back or welding on a tang will probably require the services of a gunsmith. C & S does offer a "no bite" version of the Type I hammer that has the rear of the shank contoured inward to avoid pinching.
This was my old "Duty Hi Power". Besides the Novak fixed sights and Spegel delrin stocks, it has the C&S Type I abbreviated ring hammer to alleviate hammer bite and works fine for me in that regard.
I routinely use and recommend 18.5-lb. conventional recoil springs in the Hi Power rather than the 17-lb. factory standard. For me, the heavier spring works just fine with both standard and +P 9mm loads. If you do not have a strong hold for whatever reason, your defensive 9mm Hi Power might be better with the standard 17-lb. spring. The reason is that the heavier the recoil spring, the more firm the grip must be to avoid the gun malfunctioning. There is a minimal level of force required to hold the frame in place so that the recoil spring can be compressed against it. It is possible that one's shooting hand or arm be injured before the need to return fire ceases. I continue to use the 18.5-lb. springs, but this is something you might consider.
Extended slide releases are not needed on the Hi Power in my opinion. It's been my experience that they're prone to be accidentally engaged by the shooting hand, prematurely locking the slide back with rounds left to fire. The consequences in an actual gunfight or deadly force scenario are obvious. If right-handed or inserting the magazine with the left hand the left thumb can disengage the standard slide release lever or the slide itself can be pulled back and released.
Unless your pistol just flat won't group, I do not find the fitting of a match barrel to be necessary, but don't argue against it so long as reliability is retained. Most of these will be more tightly chambered than factory barrels so be sure that the Hi Power works reliably with the match barrel before counting on it.
I have no strong opinions on finishes for the defensive Hi Power and normally use plain matte blue, at least for the frame.
I also use recoil buffers in my Hi Powers and have had absolutely no problem with them with any ammunition use. Some folks are concerned that the thing might come apart in their pistol at the most inopportune times. They will if not replaced when heavily used, but an inspection during cleaning will tell you if it is time to change them out or not. On the other hand, a simple solution is to use the buffer at the range and simply remove it when you get home and clean the Hi Power before carrying it for self-protection.
What has been postulated here is that the defensive Hi Power must be reliable, safe, easy to get into action, have sights you can quickly see, and have a decent trigger pull. All of this is for naught if you don't use quality magazines. For carry, I recommend the factory Browning magazines or those by Mec-Gar, who make the factory Browning magazines. Second choice would be good condition Inglis surplus magazines and finally, the KRD 15 and 17 round magazines. I would use the Post-Ban 10-round magazines before I'd use some of the second rate aftermarket Pre-Ban magazines that may or may not be reliable. Even if using high quality magazines, test each and every one in your pistol with the ammunition that you intend to use. If you change ammunition, retest.
It remains my opinion that the Hi Power, though now "dated", remains a most viable and world class pistol for not only self-protection, but also just plain fun. Perhaps "dated" is not quite right. Could it be that time-proven is?