Table of Contents
Introduction
Cautions
Gun Sizes
- Full Size
- Crossover Pistol
- Compact
- Slim
- Sub Compact
- Micro Compact
Introduction
At some point in every new or would-be gun owner’s life comes along what some might consider a rite of passage: picking the right gun. A major part of an informed selection is understanding various aspects and features of a weapon – and that includes the size. Smaller pistol frame weapons are not (necessarily) easier to shoot than bigger ones. Larger pistols often do not have greater magazine capacity or what is so often referred to as “knock-down power”. A grasp of types of handguns, by which we mean full-size vs compact vs subcompact, etc. (to say nothing of Commander vs. Officers model vs. whatever a “mouse gun” is!) is important. That’s not just from a nomenclature perspective, either. Each has an intended use and attendant advantages/disadvantages brought on by size and design – even within the same brand. In short, gun sizes matter.
Beware the advice of the clerk, your friend, or the self-proclaimed expert!
• Just take me to the damn guide already
Cautions
There will be caveats, qualifiers, and stipulations in any collation like this, and a pistol size chart is no different. In that context, the following guide to different sizes and types of handguns will suggest a general definition of pistol frame types and gun sizes based on actual measurements (e.g. barrel length) rather than a manufacturer’s naming convention.
It will also suggest idealized circumstantial roles for each, i.e. the conditions and context under which a compact or sub-compact (et al.) pistol might be more or less appropriate.
This grandiose grimoire of handgun gradation was originally compiled by Ser Plissken, who strove mightily to compile much lore on our behalf. Our great thanks to House Plissken, and to all of those others who have since contributed to it. Any inaccuracies are solely the fault of the Mad Duo, who, on a 1:6 scale, frequently have difficulty drinking at a 1:1 scale.
The prospective new supporter of Second Amendment rights walks into a gun store, perhaps alone or maybe with a friend, and begins that search. Whether they are there for anything specific or not, it always starts the same.
Eyes go to the long, glass-enclosed display case. They begin to scan the different options on the wall, often drawn to whatever first catches the eye, something they’ve seen before on film or in the hands of a friend – or perhaps, function aside, whatever is most aesthetically pleasing.
They meander closer and closer until the counter stops them (or you). You look down. You take a moment to register what you’re looking at, and it’s futile because your eye doesn’t know where to go first.
In this case, lined up for display, with price and make/model tags hanging off of each, are a variety of pistols. Behind the counter, like a backsplash, there are even more options. One or two, in particular, stand out from the others, and the thought enters the mind.
“I want one of those.”
Good, as Obi-Wan Kenobi said: “That’s good. You’ve taken your first step into a larger world.”
But be careful what you ask to look at, and a thousand times, be careful who you ask for advice!
We who have come before you, new prospective gun-owner, have been there and done that.
Because of our experience (much of the lessons learned the hard way), we recognize there are perils that come with the first walk into the fun gun shop where you decide you want to buy a pistol.
Bad advice can completely derail your first purchase and, for a long time, leave you with the wrong idea. A misinformed perspective when selecting a pistol (or any firearm for that matter) can affect your ability to properly use the weapon. It could have a negative impact on your experience with it, your enjoyment of it, or in the worst case, the outcome of an Event wherein you’re compelled to defend yourself with it.
None of those is a Good Thing, particularly in exigent circumstances that call for deadly force.
Depending on where you are, the person behind that counter may not deliver good advice. No offense to your friend, but he may not give good advice. In fact, there’s a pretty good chance that person doesn’t have a damn clue what gun you should use, or why.
Especially if he’s just reciting conventional wisdom or what he’s read on the interwebz.
“I’m looking for a pistol my girlfriend and I can both shoot. It’s for home defense, so mostly it’ll be, but she’ll need it when I’m out of town though. But she has small hands, so I need something she can handle.”
“Well then,” the pistolero-guru behind the counter responds, “what you need is a Micro-Compact, like a P365, Hellcat, or GX4! They’re really small. A Micro-Compact is small enough she can get a good grip on it, and they carry a lotta rounds. It’s the perfect size for both of you.”
Our goal is to help you navigate this decision-making with a reference guide to help with your due diligence. Maybe we can help you with your first gun purchase. If not, hopefully, we can assist you with an informed selection on your next pass. Let’s face it. These things aren’t like potato chips. You never take just one and stop there.
Some things to note:
• This will be as comprehensive as we can make it, but it will necessarily remain incomplete. We will update or answer questions as often as possible.
• This guide is written in the context of active, defensive use i.e. concealed carry or securely staged for pragmatic home defense. If you’re looking at a .454 Casull to hunt with and figure it’ll do for self defense of the hearth and home “just in case”, or if you’re bound and determined to buy a .50 caliber Desert Eagle because Arnie had one, this won’t do you much good.
• The choice of a defensive handgun should be a well-considered process. Such a weapon can take a life and/or cost you your freedom; its selection should not be taken lightly.
• This guide will suggest ideal circumstantial roles for a variety of semi-automatic pistols. This should not be interpreted to mean such roles are exclusive to all others, nor that our guidelines are the only guidelines. Don’t take just our word for it, but do take our word for it at least in part!
• Holster selections and carry methodologies should similarly be interpreted as broad guidance only.
• Although handguns are often/colloquially divided into four (4) sizes [full, compact, sub-compact, and “pocket pistols”], we will be a little stricter with our definitions. This is not to confuse the issue or to be pedantic, but rather in the interest of clarity for those whose research takes them to places that use differing terminology.
• Some of the examples below may not match the designations given to a weapon by its manufacturer. We’re categorizing them based on such size dimensions as weapon height and barrel length. The fact that a company calls a weapon something doesn’t mean it actually is in practical terms.
“Paint stripes on a toad, he does not become a tiger.” Sandor Clegane
Let’s get to it.
GUN SIZES
- Full Size
- Crossover
- Compact
- Slim
- Subcompact
- Micro Compact
Remember when considering a particular gun size: TANSTAAFL. There ain’t no such thing as a free lunch. You can have complete concealability, high magazine capacity, reduced recoil impulse, and all sorts of good attributes…but you can’t have ’em all. One thing trades for another.
1. Full-Size Pistol
A full-size pistol is usually the original form of most semi-automatic handguns on the market (by their respective manufacturer). This is because, more often than not, they were designed and developed to meet the criteria of a sidearm contract for use in a duty role, like Military or Law Enforcement use. Thus you will often see a full size/full frame pistol carried “overtly” in a duty-style holster attached to a gunbelt, either as a primary or secondary weapon.
• Gun Sizes
Full-sized pistols are usually characterized by an average height (including grip length) of 5.5 in. and a barrel length of 4.5 to 5 in., give or take a quarter of an inch, depending on the manufacturer. They are usually (though not always) chambered in one of the “big three” calibers: 9mm, 40 S&W, and.45ACP, with a typical magazine capacity of 13 to 17 rounds. This may be greater if “extendos” or magazine extensions are available. In some cases, a variation of full size pistol will be offered where the full-sized frame is topped by an extended length slide or “longslide” to accommodate a 5 in. or greater length barrel (primarily for the longer sight radius, softer recoil impulse, and resultant improved accuracy).
• Full Size Pistol Types
Examples of a full-size pistol include (but are not limited to) such weapons as the Glock 17, 21, 22, 34, and 41; the HK USP Tactical, P30L, VP9 Tactical, HK45, and HK45 Tactical; the SIG P226, P320 XFULL, and P320 M17; the FNH FNX-4, FNS-9 Longslide, FN-509 Tactical; the Beretta M9/92F (and all variants thereof), APX Target, and APX Combat; the S&W M&P 2.0 CORE Pro Series 5 in.; and the Colt 1911A1, 2011, and similar type pistols from other manufacturers.
• Recommended Applications
A full size pistol is a good consideration for someone in a uniformed law enforcement or armed security role who prefers to or must purchase their own handgun. A responsible armed citizen might also use such a weapon for defensive purposes, or for competition. Most (not all) of those using such a handgun would be best served deploying it from an overt/OWB (Outside the Waistband) holster like the Safariland ALS/SLS or BLACKHAWK Omnivore, particularly from an exterior gun belt.
• Carry Concerns
Problems that might be found with a full size pistol will generally pertain to concealment. Such handguns are more difficult to carry on your person without printing. There are exceptions, of course. Wardrobe and holster selection will mitigate this, as will the individual’s physicality. If you’re a guy or gal built on a larger frame (see what we did there?), you’ll likely find it as easy to conceal a Glock 17 as a more average-sized person could a Glock 19.
2. Compact Pistol
A compact size pistol is, as the name might suggest, a slightly smaller version of a full size pistol, both in slide/barrel and grip length/height. They’re big enough to serve in a duty-use role like their bigger (full size) brothers, but small enough to lend themselves well to concealed carry use. The latter is the largest contributing factor to their popularity.
Because of this, the compact size handgun is considered to be the “Goldilocks” of pistol sizes. It fulfills the two primary roles of a pistol (overt secondary and concealed primary) juuuust right, with an adequate ammo capacity in its standard form. It’s not too big to conceal, but it’s not so small that you’re sacrificing ammo capacity or accuracy potential by going too short on the barrel.
• Gun Sizes
A compact size pistol is characterized by an average height (including grip length) of 5.25 in. and a barrel length of 4 to 4.5 in., give or take a quarter of an inch, depending on the manufacturer. They are usually (though not always) chambered in one of the “big three” calibers: 9mm, 40 S&W, and.45ACP, with a typical magazine capacity of 8 to 15 rounds. This may be greater if “extendos” or magazine extensions are available
• Compact Size Pistol Types
Examples of compact sized pistols include: Glock 19 and 23; HK USP Compact, HK45 Compact, and Compact Tactical; the SIG P229, P320 XCARRY, and P320 M18; the FN-509 Midsize; the Beretta APX, 92X Centurion, and PX4 Storm Compact Carry; and the Colt Combat Unit CCO (along with similar size 1911 and 2011 type pistols from other manufacturers).
• Recommended Applications
You might consider a compact size pistol if you need a jack-of-all-trades-sized weapon that can handle both of the two primary uses of a pistol (duty sidearm/overtly carried secondary weapon and concealed carry) without offering much of a disadvantage in either role. (More than one member of our team has carried a Glock 19 for years, over a decade even, both on duty in uniform and off duty as an EDC pistol.
Ser Plissken, for instance, a man who works for one of the largest police agencies in the world, declined an offer to switch to the G17 from G19 because having the former as a duty weapon meant he wouldn’t be able to carry the latter as off duty gun (don’t ask why — most law enforcement agencies boast as much absurdity and nonsensical rules as the military, which is saying something).
As he explained, “Since the Glock 19 does the concealed carry job better than the Glock 17, keeping it as my ‘do-both-gun’ outweighed any benefits the Glock 17 would have offered with its configuration’s duty role bias.
Another thing to consider – if you have smaller hands, you might need the grip length of a full size pistol. Therefore the compact size ought to be perfect for you.
• Carry Concerns
Issues that might occur with a compact size pistol generally come from the concealment side of things, when you really try to conceal the thing. Examples of this might include:
Circumstances of deep concealment
Carrying in a place where going heeled is in an area where doing so is frowned upon (like the workplace)
In public, where there is posted signage against the carrying of a weapon
Occasions when a mandatory dress code makes it more difficult to conceal the shape and location of the weapon.
In cases like this, one might prefer something even smaller and easier to conceal than a compact size pistol. Should that be the case, there are smaller sizes to choose from (sub-compact, micro-compact, and certain crossover pistols), each with corresponding advantages and disadvantages.
3. Crossover Pistol
Generally speaking, a crossover pistol combines features of both full-size and compact size pistols (a very common example of which is the Glock 19X). A crossover pistol by function and design isn’t particularly new as far as configurations go, but the phrase used to describe them is. Since “crossover pistol” is recently in vogue (and likely to continue that way), we’ll use it here too.
• Gun Sizes
A crossover size pistol may come from the manufacturer as a specific model. Others are more of a DIY product. Most often, they’ll be characterized in one of two ways, although on occasion, there is a third:
- A compact size slide with a full-size grip length and height (q.v.) or
- A full size slide/barrel with compact size grip length/height.
- Occasionally it will be a splice between compact and subcompact pistol sizes (see below), including a full size or compact size pistol with the grip length chopped down to compact or subcompact length (respectively).
• Crossover Size Pistol Types
Examples of crossover pistols include the Glock 19X, 43X, and 45; the HK VP9, VP40, P30, and USP; the SIG P320 (depending on slide, frame, and magazine combination); the FN509, FNS-9, and FNS-40; the Beretta APX, Px4 Storm and Px4Storm Carry; the S&W M&P M2.0; and the Colt Commander (as well as similar 1911 and 2011 style pistols from other manufacturers). For “aftermarket” or DIY options, it’s not uncommon to see a Glock 19 with its grip chopped to Glock 26 length, or the likes of a G17/G34 with the grip chopped to G19 length.
• Recommended Applications
You might consider a crossover pistol for a few reasons.
-
- In the case of the factory-offered variety where the slide is the compact length, and the grip is full sized, the longer grip tends to offer the shooter a greater degree of control over the recoil impulse and muzzle rise of a wholly compact sized pistol, as well as the magazine capacity of a full size weapon without an exposed magazine hanging out of the mag well (in cases where there’s a degree of magazine cross-compatibility between frame sizes).
- Familiarity and proficiency with a compact size pistol may make that lesser slide length desirable; similarly, a crossover modification might be made in anticipation of (and to offset) something that might add to the length of a pistol (something like a compensator or threaded barrel).
- Conversely, taking the relative slide to grip in reverse, a full size slide/barrel length with a compact size height/grip length might be sought by someone who wants the concealment properties of a compact pistol — where the grip length is the common denominator in regards to how much the pistol will print or poke from under the cover garment — with the longer sight radius and softer recoil impulse of a full length slide and barrel.
• Carry Concerns
Problems that might be encountered with a crossover pistol will likely be related to selecting the wrong configuration for your intended purpose.
- If your plan was to carry it concealed and, for example, you didn’t account for the longer grip length/height of a full size with the shorter slide of a compact because you believe(d) slide length is more important to concealment than grip length (it isn’t), then you’re going to be frustrated. You’re effectively going to be attempting to conceal a full size handgun, with all the attendant difficulties.
- On the flip side, if you’ve got large hands that would benefit from a longer grip length, but you’re now gripping the shorter grip of a compact or sub-compact, now your pinky finger is either hanging off the bottom of the grip. Or, it’s getting pinched between the frame and the magazine whenever you perform a reload (which sucks).
Make sure the crossover is what you really want/need, in the appropriate relative configuration.
4. Slim Size Pistol
The handguns referred to as “slim size” pistols are a relatively recent convention in the handgun world, making their appearance after years of end-user demand. The easiest way to describe a slim size pistol (particularly in comparison to those above) is just to say “it’s a single stack version of a double stack pistol”; usually in the compact or sub-compact size.
• Gun Sizes
A slim size pistol is characterized by one trait: its width. Where most compact pistols are just shorter versions of full size pistols in both slide and grip length/heigh, the slim size takes it a step further and makes for a thinner pistol by shrinking the width of the frame and slide and transitioning from a double stack to single stack magazine.
As an example, the Glock 48 is often (colloquially) referred to as a “single stack Glock 19”; something the gun community had been asking Glock to make for at least a decade before it came along. In other words, it’s effectively a pistol as tall and long as a Glock 19 but substantially slimmer in profile.
In some cases, a slim size pistol’s magazine will be a “staggered stack” rather than a true single-stack magazine. However, it achieves the same slimming effect in contrast to a double stack mag.
• Slim Size Pistol Types
Specimens of the slim size pistols include the Glock 43X and 48, the SIG P365XL, and the Colt Combat Elite Defender (and similar 1911 type pistols from other manufacturers).
Not many options, right? It’s slim pickings.
See what we did there?
• Recommended Applications
A slim size pistol would be an excellent option if you find yourself wearing a suit and you’re actively carrying the weapon in a concealed manner; that lesser girth, so to speak (*snicker*) compared to a compact size pistol lends itself better to carrying a weapon in such apparel — and no reduction in proportional barrel length. Likewise, the slimmer grip size will be appealing to those who have smaller hands and might have difficulty getting a good master grip on a double stack compact size weapon.
• Carry Concerns
One of the considerations to carrying a slim-size pistol is ammunition capacity, particularly as compared to a double stack compact firearm (even more so with a full-size double-stack). It’s a trade-off, size vs. capacity. The reduction in width obviously comes with a reduction in space available. As a result, one normally ends up with a magazine capacity equivalent to (or even less than) a sub-compact size pistol. That can certainly be an unattractive feature, no matter the intended use (it’s hard to imagine anyone not wanting as many bullets as possible in a fight).
There are some exceptions to this, however. Take as an example the Glock 43X and Glock 48. Shield Arms developed first the S15 magazine, then the S15 Gen2. The S15 magazine is made of steel, thus allowing for thinner walls than the standard factory polymer. This bumps the 10-round magazine capacity of the G43X and G48 up to 15 rounds — the same as the Glock 19. While no one has yet spoken definitively of these aftermarket magazines (as of those writing), initial reports have been very positive. [The potential issue with a magazine built this way stems from the requirement of a steel mag release button to replace the factory polymer magazine release button, lest the polymer wears down from constantly rubbing against the steel magazine bodies.]
Many of us here and at Breach-Bang-Clear trust and use S15 magazines, but your mileage may vary.
5. Sub-Compact Pistol
A sub-compact pistol is usually an even smaller version (than the compact, that is) of a full-size model of pistol. It has the same relative kinship to a compact pistol that a compact does to a full size. Take a double stack pistol, give it a shorter barrel and slide length, with a reduced height and grip length, a sub-compact pistol is what you’d end up with.
• Gun Sizes
A sub-compact pistol is characterized by a barrel length of 3 to 4 inches, give or take a quarter of an inch or so, depending upon the manufacturer. They are usually (though not always) chambered in one of the “big three” calibers: 9mm, 40 S&W, and.45ACP with a typical magazine capacity of 8 to 12 rounds (more with an extension, of course).
What particularly characterizes a sub-compact pistol is its grip length and magazine basepad. It is almost always so short that one’s pinky finger will always be hanging off the bottom of the grip, swinging freely back and forth under the magazine’s floor plate (if it’s a flush-fitting magazine). Therefore, you’ll always see a subcompact pistol’s grip length continued as an extension of the magazine itself, where a rest for the pinky finger is incorporated into an extended floor plate or base pad. This allows for a full-handed grip on the pistol.
Sometimes, this grip accommodating extension also functions as an extension to the magazine itself. This adds 1 to 3 (or more) additional rounds to the overall magazine capacity. This is, of course, dependent upon the model of the extension offered by the factory or aftermarket.
It is in the subcompact pistols (and smaller) that we begin seeing common calibers other than the “big three”; .380 ACP is the most common of those, though .25s and .22s might also make an appearance here.
• Sub-Compact Size Pistol Types
Sub-Compact size pistols include such models as the Glock 26, G27, and G30; the HK VP9SK, P30SK, and P2000SK; FN509 Compact and FNS-9 Compact; the S&W M&P 2.0 Subcompact; the Sig P320 Subcompact; and the Beretta Px4 Storm Subcompact.
• Recommended Applications
You might consider a subcompact pistol if you’re already carrying a full size or compact size pistol as your primary weapon and would like a backup piece that uses the same magazine pattern. (This is usually but not always the case, so make sure to confirm before spending money.) This holds true regardless of whether you’re in an LE or similar role, or as a responsible armed citizen.
Ser Plissken says (and he’s right, even if hurts someone’s feelings), “If you’re not carrying a subcompact for that sort of consistency, and it’s your sole carry piece, you’re probably just lazy about dressing around a compact size weapon to conceal it properly. That’s putting the comfort of clothing over the capability of your tool(s), with no care about an awkward grip and the snappier recoil impulse that comes from a shorter barrel — something that will substantially degrade the ability to effectively engage in any instance beyond an extreme close quarter shot.”
• Carry Concerns
In the context of their intended purpose, sub-compact pistols don’t really offer many advantages in terms of concealment but they do detract from the ability to deliver a precise shot, they reduce ammunition capacity, and they’re awkward to grip. Although you can use compact and full-size magazines in a sub-compact, if they’re double-stack Glock mags, you’re bringing the grip length back up to compact size or greater anyway. Remember: Grip length is harder to conceal than slide length.
“I was initially authorized to carry a Glock 26 as an off-duty weapon or backup gun to a G19 primary at work, but I stopped carrying it. I now only rock out with my Glock 19. Reason being, I prefer to carry the G19 anyway. I get a better grip and shoot more accurately with it as a consequence of its longer barrel and grip length. Since the Glock26 is just as wide as the Glock 17 and 19, I’m losing more than I’m gaining. Consider the respective dimensions. The G26 is hardly an inch shorter than the Glock 19 in terms of length and height. If you’re okay with carrying a Glock 26 or similar subcompact pistol, you might as well just carry the Glock 19 or a comparable compact size pistol anyway. You’ll barely notice the difference when it’s holstered.” Frank Woods, Ser Plissken
On the topic of holsters, most people will (with some sartorial research and a little effort) be able to make a compact size weapon disappear. Outside of the ability to use a larger magazine to compensate for the lack of ammo in standard sub-compact magazines, you gain very little by adjusting to the misnamed “smaller” size.
This is probably why the niche once dominated by the sub-compact pistol is being usurped by a combination of the slim size and the…
6. Micro-Compact Pistol
A micro-compact, as you might have expected, is to a sub-compact as a slim size is to a compact size, which is to say: the barrel length and grip length/height is usually the same as a subcompact pistol, but the width is shrunk down from double stack to single or staggered stack.
• Gun Sizes
A micro-compact pistol is usually characterized by…being a single stack version of a doublestack sub-compact pistol. That’s really all there is to it. If you’ve ever heard the term Pocket Pistol, and it was being used to refer to a tiny revolver (or maybe a derringer), a micro-compact size semi-automatic pistol is what was meant. Magazine capacity is usually anywhere from 6 to (nowadays) 12 or more rounds, with a barrel length averaging 3.5 in., give or take a quarter to half an inch. We’ve seen barrels as short as 2.75 in. as of this writing, but there may be others that are smaller.
Micro-Compact Pistols also feature calibers outside the “big three”, again primarily the .380 ACP (although there are others).
• Sub-Compact Size Pistol Types
Specimens of the micro-compact pistol include weapons such as the Glock 36, 42, and 43; the FN503; S&W M&P Shield; SIG P365, P238, and P938; the Colt Mustang, the Springfield Hellcat; and the Taurus G4X.
• Recommended Applications
A micro-compact size pistol is for when you really need to hide it, if you need something to carry while you “run to the store real quick” and don’t anticipate getting into (or sticking around for) a gunfight. Of course, we don’t ever expect a gunfight, do we?
• Carry Concerns
Most of the problems you might find with a micro-compact size pistol will (again) be related to picking it for the wrong job. A micro-compact size pistol is a niche gun, tailor-made for circumstances like those described above.
Anything else beyond those, any situation requiring greater capability or capacity, is (or should be) a no-go for the micro-compact size pistol. It should not be the sort of handgun you rely upon too heavily or carry multiple magazines for as you might if in anticipation of shooting so much that you need to reload more than once. The micro-compact pistol size pistol is for those moments when you need to get out of Dodge right now. If someone is presenting a threat and/or trying to stop you, you address the threat and then get out of Dodge. Like, two minutes ago.
Think of it as an E&E gun. It’s not for going after bad guys or fighting toe to toe. It’s for getting away from bad guys. Do not rely upon a micro-compact pistol if you require more defensive capability from your sidearm.
Although that might sound like a recommendation against a micro-compact, most of us would rather you carry some gun vs. no gun. If a micro-compact is what it takes to have you go heeled, then micro-compact it is. There’s an excellent argument to be made that the main goal of a responsibly armed citizen (at least one that is out of the home) ought to be breaking contact anyway.
This is a great time to be buying a defensive handgun. That might seem strange (even ridiculous), but improvements in weapon design and technology are coming hard and fast. There are options today that are far and away better than those of just a decade ago. The Glock 48, Springfield Hellcat, SIG p365 – all were either significant jumps in an important feature (like magazine capacity) or the answer to long-asked-for appeals (like a “single-stack G19”).
Today’s compact pistol has far greater performance potential than full sized handguns of a few years back; sub-compacts are arguably just as much improved. Micro-compacts are a world away better than their few historical forbears.
There you have it.
We’ve broken the most common semi-automatic pistols (those chambered in the “big three” popular cartridges: 9mm, .40 S&W, and .45 ACP) into six primary gun sizes. We’ve categorized them, given you an idea of their dimensions, and proposed the most idealized circumstances they best lend themselves to.
Study the information. Use it as a guide to help determine the appropriate pistol for your intended use — weighed against what each option has to offer…and the disadvantages they impose.
When the day comes that you walk into that shop with money to spend on your first (or next) pistol, go armed (see what we did there) with the knowledge of an informed buyer. If possible, and this might be admittedly difficult, get more than one option in your hands. Try them out. Put some rounds downrange. Check out the ergonomics, the trigger pull, etc.
Even if you’re unable to do so, just knowing ahead of time the advantages and disadvantages of each frame style will help you achieve the best possible choice.
Stay safe, shoot straight, and make it count.
