Longevity of .40 vs. 9mm pistols

[9mmepiphany]

I stand properly corrected. But that correction of my original error seems to reinforce my original point: that it's wrong to say a gun designed for 9mm can't be adapted to run a higher (or in the case of the P226/229, a hotter) caliber. THAT -- guns adapted weren't as good as guns designed to run .40 -- was the original point of debate. If that was the original point, then the P220 is the basic design used in all of the class P-series guns, and the various models just incorporate changes (adaptations) appropriate to the application.

I'm not sure if I wasn't clear or just misunderstood, but I'll try again.

The prior point I address was your statement

The P220 was first built in .45.

It wasn't. But that doesn't mean that it was designed for the 9mm either.

It was designed for the .45ACP class of cartridges...single stack magazine, accommodating longer length and wider cartridges than needed for a gun designed for the 9x19mm. But they did first build it in 9mm for the contract to replace the SIG 210

 

[9mmepiphany]

My point in all of this was that a GUN DESIGNED FROM THE GROUND UP to fire .40 really doesn't exist (although the M&P Pro may be an exception.) All of the the other .40 guns cited-- including some that are available only in .40, are fundamentally the same designs as other models offered by the same gun makers, with adjustments made to allow these "upgraded" 9mm guns to handle a different (sometimes HOTTER) caliber.

OK, I'll bite, which 9mm gun in the H&K line was the USP an adaption of?

 

[9mmepiphany]

The P229 in 9mm and the P228 in 9mm are very similar guns -- except for the slides.

I'm unclear if you are under the impression that the 9mm 229 and the .40/357 229 were the same gun...prior to the 229-1 upgrade.

They weren't. The 9mm 229 has more in common with the 228, than it has with the .40/357 229

Had SIG chosen to just change the P228 to use a milled Stainless Slide, would it be correct to say that that the P228 was REDESIGNED to shoot the .40? Or would we simply say they made changes (adaptations) that allowed the P228 to use .40? And what are the differences between the P228 and P229? They are VERY similar

The 9mm 229 is simply a 228 with a milled slide (well, that and the current rail)

The differences are to the frame and the locking block to take the additional battering...that is why the .40 229 isn't just an adaption of the 228; it shares neither the slide nor frame. That is why .40/357 magazine won't fit in the 9mm 229...until the change to the 229-1

 

[Walt Sherrill]

OK, I'll bite, which 9mm gun in the H&K line was the USP an adaption of?

As I understand it, design work began in 1990, and USP prototypes participated in testing alongside H&K's entry into the U.S. Special Operations Command OHWS program; the OHWS program led to the development of the MK23, which was a .45 weapon. While Wikipedia says the USP was built around the .40 S&W round, what little I've been able to find about the OHWS program has led me to believe that the USP prototypes used in that program were 9mm, not .40.

According to Wikipedia, those prototypes were refined in 1992, based on input from the OHWS trials, and the design was finalized in December of the same year. If H&K had any hopes of developing a gun for NATO or the U.S., they wouldn't be focused .solely on 40.

The WIKI article is says that H&K had .40 as their design focus for the USP line, and that would be critical for LEO sales in the U.S. -- as .40 was the hot item in the 90's. But that would have been a big NO SALE for any NATO military organization -- as 9mm was the round of choice, there. Still is. Commercial versions of the USP guns were introduced several years later, with a .40 version coming out first followed quickly by the 9mm version. A .45 version was offered a couple of years later.

Perhaps the USP40 and the USP9 were guns developed on a dual path with slightly different objectives. If so, the USP in .40 wasn't based on a 9mm design that had been ADAPTED. Maybe the .40 round was "THE" design focus for the USP line, and the 9 version was a adaptation -- but it's not clear from the evidence available. If in fact the OHWS weapons were 9mm, the evidence is even less clear.

The differences are to the frame and the locking block to take the additional battering...that is why the .40 229 isn't just an adaption of the 228; it shares neither the slide nor frame. That is why .40/357 magazine won't fit in the 9mm 229...until the change to the 229-1

Actually, my point was that they were both adaptations of the P226. You point out other differences, as well. I'm clearly less familiar with SIGs than some here. The differences between the 228 and 229 are greater than I realized, but still, they are subtle changes that could have been done to the 228 -- but weren't. SIG had its reasons.

But we've kind of come back to the same point where mavracer and I last touched: semantics -- i.e., meaning.

The original claim was that only guns that were designed for the .40 would last. It may be that the USP and the S&W M&P were designed from scratch to shoot the .40 -- but in the case of the USP that seems opaque. In the case of the SIG guns, they've maintained the same basic gun design, but strengthened this part, replaced that one, changed the slide, etc. Is that a GUN DESIGNED TO SHOOT .40 or is that a GUN MODIFIED TO SHOOT .40? My argument was that the 229 was a variation of the 226, but modified to work better with the .40. I called that adaptation or modification. Others seemed to suggest NEW DESIGN. The original 226 was 9mm (for the US military tests). Subsequent 226s were different -- yet still fundamentally the same gun, but with many small changes made to accommodate hotter rounds.

Maybe we aren't really discussing guns -- we're discussing the meaning we attach to certain words and concepts.

AN earlier poster said that .40s based on 9mm but adapted to shoot .40 were likely to have a shorter life than ones designed solely for the .40 rounds. Which guns might fall in that first class of weaponry? Can someone name some?

 

[tarosean]

Can you name a single .40 that was designed, from the ground up, for the .40 round?

S&W 4006 since it was designed around their round. Course history shows that glock quickly adapted their 17 into a 40S&W after the unveiling of the new round, beating S&W to the market...

 

[9mmepiphany]

AN earlier poster said that .40s based on 9mm but adapted to shoot .40 were likely to have a shorter life than ones designed solely for the .40 rounds. Which guns might fall in that first class of weaponry? Can someone name some?

A much easier task, as they usually became items of interest when failures became known...besides the obvious FN P35 already mentioned

The two that come readily to mind are the:
1. Beretta 92 -> 96; cracked slides
2. Gen2 Glock G17 -> G22; kaboom

...a slightly different issue, but a shorter useful life:
3. H&K P7M13 -> P7M10... too ugly to take out and shoot

 

[AustinTX]

A much easier task, as they usually became items of interest when failures became known...besides the obvious FN P35 already mentioned

The two that come readily to mind are the:
1. Beretta 92 -> 96; cracked slides
2. Gen2 Glock G17 -> G22; kaboom

...a slightly different issue, but a shorter useful life:
3. H&K P7M13 -> P7M10... too ugly to take out and shoot

Not to nitpick, but the problem with the early 96 was cracked frames, not slides. That's why Beretta beefed up the dustcover, giving us the curved dustcover that some purists dislike. The Brigadier slide was at times also used to reduce frame battering by reducing slide velocity, but the Brig slide was not standard equipment.

The first 96 was nothing more than a bored-out 92. It even used the same weight recoil spring, which always seemed kind of insane to me. Afterward, changes made to enhance the durability of the 96 were carried over to the 92 as well.

 

[Walt Sherrill]

And doesn't the fact that both of these guns (the 96 and the 22) have been upgraded and now have comparable service lives to other .40s suggest that the fact that they were based on 9mm guns isn't really the issue -- only that they were NOT properly upgraded or modified AT FIRST?

Is anyone seriously arguing that the Glock 22 has a shorter service life than other .40 semi-autos, or that the 96 is now STILL a fundamentally short-lived gun?

If they can be (and are) upgraded, improved, or otherwise modified so that early problems are resolved-- how do such guns really differ from nearly all of the other .40s out there? (Other than the need for the gun maker to have to recall some guns.) Recalls happen a lot, and not just with caliber upgrades...

 

[JohnKSa]

Can you name a single .40 that was designed, from the ground up, for the .40 round?

The original H&K USP was designed as a .40S&W according to the advertising propaganda when it was introduced.

Pressure is what drives the process of firing a gun. Without pressure absolutely nothing happens so no wear and tear and failure of components will occur. Like I stated before without pressure you simply have an inert piece of machinery. So, no pressure, no failures.

Correct. However pressure is contained safely or the gun would be dangerous to fire. When a gun fails to contain the pressure the gun doesn't wear out, it blows up.

The higher the pressure created by the firing of the firearm the more stress is placed on all the components that make up a firearm.

That is incorrect. The higher the pressure, the more stress is placed on the components that contain the pressure. Most of the parts in a handgun do not actually contain pressure. The barrel does, and the breechface does as do the locking surfaces. However, the frame does not contain the pressure of firing and therefore the pressure level means virtually nothing to the frame. The same is true of most of the slide with the exception of locking surfaces and the breechface.

Furthermore, the stress generated by pressure does stress the pressure containing parts, but (with the possible exception of locking surfaces) it does not really wear them. If it did, eventually the gun would fail from the pressure and that failure would manifest as a containment failure--a pressure containing part would rupture and release the pressure. Clearly we don't see guns wearing out and failing by blowing up. They wear out from battering, impact stress, friction, etc. The wear due to those factors is essentially independent of the discharge and depends on things like slide momentum/recoil momentum, parts inertia, play in moving parts and other design factors, proper maintenance, etc.

Less robust components for a given amount of stress means quicker failure.

This is true, as far as it goes, but again, we don't see guns failing because the pressure containing components aren't robust enough. If that were happening, we would know when a gun was worn out because it would blow up when the pressure containing components wore out and failed to contain the discharge pressure. Clearly if that were the normal way for guns to wear out, they would come from the manufacturer with a "not to exceed round count" because they wouldn't be able to risk the liability incurred if they didn't warn their customers that the gun was eventually going to blow up if it were used long enough.

 

[9mmepiphany]

Is anyone seriously arguing that the Glock 22 has a shorter service life than other .40 semi-autos

I wouldn't argue that, but I think that one could make a valid argument that the G22 has a shorter expected service life than the G17.

It has certainly been proven, over the years and generations, that it is prone to more functional issues...which may have now been reversed with the introduction of the Gen4 pistols (which seem to have been optimized more toward the .40 cartridge's characteristics)

 

[Walt Sherrill]

I wouldn't argue that, but I think that one could make a valid argument that the G22 has a shorter expected service life than the G17

Perhaps... but that's a different point. I don't think we've really addressed whether any .40 will outlive a similar model in 9mm.

If the G22 has a similar service life as other "from scratch" .40 designs, does it really matter that it really started life as a 9mm design?

This discussion started with the contention that guns NOT ORIGINALLY DESIGNED as .40s (i.e., guns upgraded from 9mm to .40) were NOT as robust as guns designed from scratch to fire .40. If that is true -- a point not proven -- it may be that the G22 is one of several exceptions to the rule.

 

[Hangingrock]

If the 9mm-Luger and the 40S&W operate at the same peak pressure (I thought that the 40S&W peak pressure was higher than the (9mm-Luger) then the 40S&W would transmit more force F=PxA on firing. Should that difference be significant and no system changes were made to account for the difference then on face value it would seem/appear the 40S&W would have a somewhat less service life on the same basic platform.

 

[9mmepiphany]

Perhaps... but that's a different point. I don't think we've really addressed whether any .40 will outlive a similar model in 9mm.

Actually that is the point of the OP

This discussion started with the contention that guns NOT ORIGINALLY DESIGNED as .40s (i.e., guns upgraded from 9mm to .40) were NOT as robust as guns designed from scratch to fire .40.

We've drifted more than a bit from the OP.

Perhaps, if you'd like to continued this line of discussion, you'll start a new thread focused on it rather than drift this thread further.

 

[mavracer]

it may be that the G22 is one of several exceptions to the rule.

If you'll go back and reread my post.

Guns that were designed around the 40 will last a long time, some guns that were designed for a 9mm and adapted for 40 have a shorter life span.

So it's not a rule but a generality, which by nature are always false sometimes.

A G17 is a extremely durable 9mm stands to reason it's going to make a more durable 40 than a Beretta 92 is.

 

[Lycidas Janwor]

Usually they do, but some take some time to get around to it. For instance Glock waited until Gen 4 to do it.

CZ is still thinking about it

Correct me if I'm wrong but the Gen 3 G23 has a heavier slide and beefier rails to compensate for the .40S&W...

 

[GLOOB]

Rails are part of the frame. The frames are identical. The total weight of the guns are identical. Per Glock website, the weight of these guns is identical at 670 grams unloaded.

 

[Lycidas Janwor]

Rails are part of the frame. The frames are identical. The total weight of the guns are identical. Per Glock website, the weight of these guns is identical at 670 grams unloaded.

Yep, it's kind of stange. The G17 (Gen 3) weighs 710g unloaded, while the G22 (Gen 3) weighs 725g unloaded. However the subcompact versions of both pistols, the G19 (Gen 3) and the G23 (Gen 3), weigh the exact same unloaded, 670g. This is strange IMHO.

 

[mavracer]

if the weights are accurate the 40 slide is prolly slightly heavier since the barrel is going to be lighter

 

[JTQ]

Originally Posted by JTQ
Usually they do, but some take some time to get around to it. For instance Glock waited until Gen 4 to do it.

Lycidas Janwor wrote,
Correct me if I'm wrong but the Gen 3 G23 has a heavier slide and beefier rails to compensate for the .40S&W...

I don't know. It is entirely possible they do. The point I was making is the entire reason for the Gen 4 Glocks was to fix problems with the .40 S&W models. Mostly with reliability with weapon mounted lights, but also durability.

 

[Walt Sherrill]

Actually that is the point of the OP...

True, but the comment I responded to was something different, more narrow, and cited in my response. Taking that path led us off down a different rabbit hole. When I said "THIS DISCUSSION" I was referring to the argument that guns NOT ORIGINALLY DESIGNED as .40s (i.e., guns upgraded from 9mm to .40) were NOT as robust as guns designed from scratch to fire .40.

I'm not sure we've really addressed the original poster's question properly. I would generally expect the 9mm versions to last longer! Otherwise you're handling a heavier round powered by more explosive material!! That handgun must cope with more FORCE and mass with the various parts of the gun sometimes moving much more quickly. Pressure is about the only thing shared by the 9mm and .40 rounds, and as noted earlier, pressure is just part of the equation. If you've got MORE of everything to manage, it must come with a cost -- there's no free lunch. (That may be why S&W has had problems with their M&Ps running .357 SIG: it's a very robust round!)

Guns that were designed around the 40 will last a long time, some guns that were designed for a 9mm and adapted for 40 have a shorter life span.

So it's not a rule but a generality, which by nature are always false sometimes.

A G17 is a extremely durable 9mm stands to reason it's going to make a more durable 40 than a Beretta 92 is.

Could be. It may also last longer than a number of "purpose-built" .40s. (We simply don't know, yet.)

The FN BHP, which was based on the 9mm design, failed when first introduced as a .40, but once updated/modified, worked quite well. Now discontinued, it appears that the .40 BHP was just a gun that the public wasn't really looking for. I think the Beretta 96 went a similar route. It's also no longer marketed (at least in the U.S.); it may also be a gun that the public wasn't looking for.

The CZ-75B .40s are also based on the 9mm design, and I've heard of no real problems with any of them. (Had a couple, myself.) I've also not heard of any problems with the newer P-07/P-09s in .40... That said, I have no idea whether there was a specific design caliber for those weapons.

If we can find a few more examples of 9mm-based guns that are or have been successful as .40s, in addition to Glock, BHP, and CZ, the assumption that non-40 based designs fail more quickly than "scratch-built" .40 designs may prove to be neither a rule nor a generality.

 

[Deaf Smith]

if the weights are accurate the 40 slide is prolly slightly heavier since the barrel is going to be lighter

No doubt. That way the recoil mass will be the same.

Note the recoil springs for the Glocks 17, 22, and 31 are the same.

I feel the Glock 22 and 31 have higher use velocities but not enough for Glock to be willing to change anything.

Deaf

 

[mavracer]

I feel the Glock 22 and 31 have higher use velocities but not enough for Glock to be willing to change anything.

Also probably the reason I hear a lot of people talk about G17s being susceptible to limp wrist FTF.

The FN BHP, which was based on the 9mm design, failed when first introduced as a .40, but once redesigned, worked quite well.

Same thing with Beretta 92-96, CZ basically has a built in failure point at the slide stop that keeps other thing from breaking. My Tac Sport which is sold as a high round count gun actually came with spare slide stops.

And to be real honest early G22s did have some growing pains as they apparently had issues with case head support.

Sig, FN, HK and S&W have all put out guns that were redesigned not just open up the breach face .006 and stuff a 40 barrel in there.

I'll also add that apparently Springfield armory is aware that you can't just stick a 40 barrel in a 9 and have a reliable durable gun as they switch the EMP 40s frame to steel.

 

[Cee Zee]

CZ slide stops do break, but it is sometimes a user-induced problem. I've got a CZ-85 Combat with 10K+ rounds through it without a problem. One reason some slide stop break is that folks install heavier recoil springs "to protect the gun," and that just causes the slide to SLAM back against the slide stop with extra force. The cure is worse than the illness.

Can you explain why this would be true? I realize that the force of the slide is going to be stopped somewhere whether it's by the spring or a slide stop. The old "equal and opposite reaction" law comes into play. It seems to me that whatever method is used to slow the slide down to a stop is going to take the same energy either way. So why is it that using a heavier spring will wear out the slide stop faster? I understand the length of time the slide stop is under pressure would be different but it seems that the total pressure at any one point would be greater with a weaker spring and that seems to me would cause the slide stop to break faster. Is there something I'm missing in this equation?

BTW we might want to remember that the P210 was made in many calibers before the P220 came along. And that includes .45 ACP. And the initial sale of P220's in the US included 9mm, .45 ACP and .38 Super models. But the earliest models in Europe were designed for the 9mm round. Still the design of the P210 showed the ability to adapt the design to .45 ACP levels. There weren't a lot of them of them sold AFAIK but there were some. Most were either the original 7.65mm and the much more abundant 9mm.

Also it seems to me that heavier bullets requiring heavier slides and springs would stress frames but again we run into our friend Newton where we learn that a lighter round fired faster generates more energy which must be dealt with unless we want the slide coming off the back end of a pistol. So I can't really see how a .45 would cause more damage to sliding parts or frames than a 9mm would as well as a .40S&W. The amount of pressure generated is what drives the parts and although the pressure isn't directly responsible for the damage it is indirectly responsible. But we see 9mm pistols made much lighter than .45 ACP pistols. Why is that? It flies in the face of Newton's laws it seems to me. My understanding is that the .45 has greater felt recoil because the length of the recoil time is longer because it is slower. It's like poking your finger in water vs. slapping water. The faster motion of a finger penetrating generates less felt resistance than a slap to the water would even if you were only using the one finger. What that tells me is that there is more to the equation than is obvious from intuition (or my intuition anyway) and that other factors come into play. So without knowledge of what those factors are in relation to every caliber of cartridge and bullet weight it seems we are guessing at what is really doing the damage to any given pistol. Why does a heavier bullet require more resistance than a lighter bullet fired with the same energy? Newton would say the forces equal out because the laws of mass and momentum are the same no matter what the size of the projectile.

In short the whole question is a lot more complicated than it would seem from observation and guesstimates. That's why we have engineers actually doing research on such things. They earn their money. Until I see the data they have I won't be convinced of anything here.

 

[Walt Sherrill]

Can you explain why this would be true? I realize that the force of the slide is going to be stopped somewhere whether it's by the spring or a slide stop. The old "equal and opposite reaction" law comes into play. It seems to me that whatever method is used to slow the slide down to a stop is going to take the same energy either way.

When the round is fired, and the slide moves back, PART of the force of the explosion is passed to the hammer spring as the slide cocks the hammer for the next shot. THAT energy does NOT return to the slide as the slide returns to battery. (It comes back later, when the hammer is dropped, and basically has minimal effect on the slide stop.) -- the force stored in the hammer spring doesn't get applied until later.

Equal and opposite is a valid point, but the forces are managed differently when the slide goes back and when it goes forward. They aren't equally applied.

On the first part of the firing cycle much of the force is transferred from the slide and barrel (which are still connected) to the recoil spring and to the frame, through the base of the recoil spring guide rod (which rests against the receiver stop on the CZ frame as the barrel starts to move to the rear. Not all of the force is stored in the recoil spring, of course. Part of it goes to the hammer spring, part to the recoil spring, and part to the frame -- and then to your hand and arm. The slide stop doesn't really come into play during that part of the firing cycle until the barrel is all the way to the rear, and a lot of the force has already been stored, and then only as the barrel is guided down (on the CZ) and stops. Only a smaller part of the recoil force is hitting the slide stop as the slide goes back. Much of the force has been transferred to the recoil spring and the hammer spring, and passed through the frame to the shooter's hand and arm. The force stored in the hammer spring is re-applied later, with the next shot.

An extra strength recoil spring retains MORE stored energy than a lower-powered spring, and if the gun continues to function (i.e., cycle, if the spring isn't too strong to prevent it) that extra force stored in the spring causes the slide to slam forward with extra force and it returns; the only thing stopping it then is the slide stop!

BTW we might want to remember that the P210 was made in many calibers before the P220 came along.

You may be correct, but I've never seen P-210s in any caibers but 9mm. .30 caliber and .22 versions -- and in my readings on the topic have never heard about other calibers and certainly not about a .45 version. I'm not sure that the P-210 grip frame could be made to accommodate the longer .45 (1.275") round than the (1.169") 9mm round! (That difference led to Glock create he .45 GAP, a shorter round needed fit a .45 bullet and case into a 9mm grip frame!! That's the reason other guns aren't easily converted to shoot .45 -- even if the rest of the design is (or can be made to be ) competent to do so. Got as source for that claim about 210s in larger calibers??

My understanding is that the .45 has greater felt recoil because the length of the recoil time is longer because it is slower.

I'm not ballistician enough to really address that point, but it seem to me that a larger caliber bullet that weighs a lot more, is moving more slowly, and is powered by more powder might have a bigger role in how recoil is experienced, and not just caliber alone...

So I can't really see how a .45 would cause more damage to sliding parts or frames than a 9mm would as well as a .40S&W. The amount of pressure generated is what drives the parts and although the pressure isn't directly responsible for the damage it is indirectly responsible.

If you got that impression from anything I wrote, I certainly didn't intend to make THAT claim! Perhaps you're misireading earlier comments by others? The P220 was built originally in .45, but may have been first put into the field in 9mm.

Pressure is a player, but it's not pressure alone that causes problems. The bulk of the prior discussions was about guns designed to shoot 9mm (from scratch) then being adapted for (i.e., moving up to) a round that fired at the same (and, perhaps higher) pressure, but doing so while shooting a round that generated more force (larger bullet, heavier bullet, more powder, etc.)

.

 

[GLOOB]

The amount of pressure generated is what drives the parts

I have an air compressor in my garage. The pressure in the tank is 125 PSI. How fast is the tank moving? How much kinetic energy does it have? How much felt recoil does an air compressor have?

we run into our friend Newton where we learn that a lighter round fired faster generates more energy which must be dealt with unless we want the slide coming off the back end of a pistol.

Newton is rolling around in his grave. Let's take a specific example of a 124 gr 9mm bullet at 1000 fps, versus a 230gr bullet at 750 fps. The kinetic energy is basically equal. (The 45ACP bullet has only 4% greater KE). But the 45ACP bullet has 39% more momentum. That translates to 39% more slide momentum. If you made each gun with the same exact slide mass, the 45ACP bullet will make the slide recoil in the neighborhood of 39% FASTER, even though the bullets have approximately the same kinetic energy, ignoring, for the moment, the effect of the recoil spring, mainspring, and slide-frame friction in the rails.

although the pressure isn't directly responsible for the damage it is indirectly responsible

The momentum has a direct, simple, straightforward, and observable relationship with slide velocity that is unalterable. But if, for some reason, you want to play the pressure game, then fine. It is, as you say, indirectly responsible. It's the driving force, so to speak. So let's look at pressure.

The peak pressure of the 9mm is 35k psi. The peak pressure of the 45ACP is 21k psi. For sake of argument, let's say the average pressure of each remains in the same ratio.

Force = pressure times area. The force that drives the bullet and slide apart is the pressure multiplied by the area of the back of the bullet. The force driving the 45ACP is only 3% less in this specific example than the force driving the 9mm.

Same force. Same energy. 45 ACP has significantly greater momentum.

If you shoot 9mm out of a 1911, you will get less wear and tear and less recoil, in general. Exception, you will get more throat erosion in the 9mm, but that is not a factor in pistols, generally speaking.

.45 has greater felt recoil because the length of the recoil time is longer because it is slower.

No, the 45 has greater felt recoil because it has more recoil. But you are correct in the duration of the impulse. Because the 45 ACP is reaching a lower velocity in this example, one can presume that the bullet stays in the barrel longer. Thus the duration of acceleration is longer. How much on an impact this has on felt recoil is debatable. But if you were to shoot 45 and 9mm out of two revolvers with the same mass and barrel lengths, I am pretty sure you would perceive significantly more recoil from the 45ACP, and particularly in a lighter gun, it wouldn't be a "gentle push" that you get out of a 1911.

Another factor in different platforms is slide travel length. I think in 45-specific platforms, the slide is going to go back a little farther on average, due to the longer cartridge length. This also has an effect on felt recoil when you factor in the recoil spring and for what happens if/when the slide reaches the end-of-rearwared travel.

Higher psi means the 9mm needs a chamber to withstand that pressure. The locking lugs need to be about the same tensile strength, due so similar peak force between the two cartridges. Pretty much all other structural and wear considerations between the two cartridges will be 45>9mm.