I don't want to make the mistake of buying the wrong caliber. I recently went to a gun shop and test fit a USP .45 compact and a USP 9. Both fit my hand like a glove, even though I have small hands. I haven't got a chance to hold a .45, and I'm wondering how much bigger it is compared to the 9mm/40.

I'm fairly sure I want the compact in .45, and the USP in .40 so I can have two different rounds to play with. Although I do like the extra capacity of the Compact in .40 caliber.

I've shot 1911 .45s and liked them, but I have never shot a USP. They feel SOLID in my hands though.

Can anyone point me in the right direction? Keep in mind I'm in Cali so I can only have 10 round mags.

The .45 will work fine. Get it and avoid the .40

Why should I avoid the .40 (just asking)?

Quoted: Why should I avoid the .40 (just asking)?

because a .45 will stop a freight train dead in its tracks!

no reason really, some people just prefer .45.

i have a usp .40 and expert .45.  the expert is the most accurate handgun (for me) i've ever owned, even over most revolvers i've shot (i can't shoot a wheelgun worth a crap sometimes).  it's been ages since i've shot a standard usp .45, but both the tac and expert seem to have basically the same accuracy, maybe a slight edge to the expert for the longer sight radius.

that being said, my .40 is not very far behind.  i can't shoot as well with it for longer ranges like the .45, but that's just me.  i had a .40 compact, and shot it just as well as my full size .40.

to me, the expert is a joy to shoot.  very smooth action, very nice recoil.  it does seem to be a little slower with more push than the 1911's i've owned/shot (but admittedly, that's not many).  it's extremely smooth-shooting, but i just think it has a bit more push.

any of them would be a great choice, really.  myself, i generally prefer capacity.  i'm looking to pick up a p2000sk in 9mm one of these days.

edited to add:

the compact's recoil system is a much different animal than the full size guns.  the full size recoil system is a thing of genius, the compacts not so much.  the pistol in any trim is an hk - with all its high points.  but, the recoil systems are vastly different.

.45 caliber holes make invisible souls...

.40 if you want to go through anybody or hunt with it.  .45 if you are looking at single persons or big holes in soft targets.  

Quoted: .40 if you want to go through anybody or hunt with it.  .45 if you are looking at single persons or big holes in soft targets.

I say .45 out of personal preference and because you mentioned getting a .45 USPc as well. That would cut down on your ammo supply logistic for one, which would be great for you if get into reloading. It is my preference because having shot plenty of both calibers I find the .45acp has much better recoil characteristics and I shoot (as do most people I've observed & talked with - used to work at an indoor range) better groups with the .45acp. That is especially true in rapid fire.

Quoted: Quoted: .40 if you want to go through anybody or hunt with it.  .45 if you are looking at single persons or big holes in soft targets.   I say .45 out of personal preference and because you mentioned getting a .45 USPc as well. That would cut down on your ammo supply logistic for one, which would be great for you if get into reloading. It is my preference because having shot plenty of both calibers I find the .45acp has much better recoil characteristics and I shoot (as do most people I've observed & talked with - used to work at an indoor range) better groups with the .45acp. That is especially true in rapid fire.

If you check the numbers,  (I am at my apartment at school not my parents where my press is so I don't have mine) you will find that the muzzle energy and the muzzle velocity for a 40 is very similair to a .357 magnum.  The .357 and the 40 give good penetration, through 4" of pine in my experience.  There is a reason that it is so popular with law enforcement.  The FBI designed (or had designed) the 10mm.  The 40 is just a shorter 10mm case.  However, in my Sierra Reloading Guide, the 40 out preforms or matches the 10mm in almost all circumstances.  

I am not a 45acp expert, but I do know that this round does not normally break 1000fps.  Heavy big bullet or not.  That is slow.  Don't get me wrong it is a good round that has served our country well over the years, but might not be right for some people.  As an example of this round.  My grandfather was issued a .45 during his Army service.  Normal target practice for him was a thick wool army blanket doubled over and strung over a wire.  If shot near the bottom of the blanket, the heavy free material would stop the bullet.  

So, the reason that the .45 has better recoil is that you are putting less energy downrange.  More mass with a heavier bullet, but less energy.  

But really, this is a .  And has been beat to death by people who get emotional and sentimental about different chamberings.  Besides, the 45 is more expensive, at least around here.

Just a quick trip to speer's website for the sake of arguement:

Round=============> 230gr .45acp  / 180gr .40 S&W  /  158gr .357MAG

Muz velocity (FPS)=========>  890  /         1025          /        1235

Energy ================>  405  /          420           /          535


I went with a manufactured ammo for consistency. All sort of arguements for non-standard loads (such as hand-loads, which run the gamut from interesting to downright hazardous) can be made, for example Speer's 200 grain +P .45acp turns out muz velo of 1080 FPS and muz energy of 518 foot lbs. Looking at the charted numbers above though we see that the .40 S&W offers a 3.6% advantage over the .45acp in terms of muzzle energy. Meanwhile, the .357mag has a 27.4% advantage over the .40 S&W.

From both my experience and these numbers I would have to say the .40 is far closer to the .45acp than the .357mag. The difference between the .40 and .45 is negligable and given that I will always go for the round with the bigger diameter and better recoil characteristics. I have shot .45 acp through everything from pumpkins to car bodies at a junk yard to pine boards to etc and it performs more than well enough for anything on two legs. Further, before we get on the old tired horse of mag capacity let me point out the thread author is limited by his state of residence to 10 rnd mags. Even if he were not, the pistol in question (H&K USP) has a stated capacity of 12 rnds (.45acp) vs. 13 rnds (.40s&w), again not enough to skew my choice.

Although this article deals with the 10mm, I always thought what it had to say about the birth of the .40 s&w was interesting.

In the infamous shoot-out with bank-robbers (armed with long-guns), the FBI had several agents killed and more wounded. They commissioned a study to find out what went wrong. The study determined that their marksmanship had been good, but the terminal ballistics of their rounds had been too slow to incapacitate the bad guys. The Chief of the FBI's Firearms unit, knowing of this new cartridge that was more powerful than anything else in an auto-pistol, suggested the FBI adopt it. The 10mm was now blazing hot, with not only the proven 1911 design and the defunct Bren Ten (which is actually a pretty good design), but also the largest and most impressive Law Enforcement Agency in the US as it's first big user! This also promised the possibility of even more pistol designs, as, in true bureaucratic fashion, there would have to be a competitive design contest to pick which pistol to buy and issue, leading more manufacturers to design 10mm handguns. In addition, more high-performance factory ammo was coming into being, including the Winchester Silvertip (175gr JHP @ 1290fps). But, then, a funny thing happened. Along came a man named Martin Fackler, who was a doctor for the Army, studying the effects of wounds simultaneously and as an adjunct to the FBI's Wound Ballistics Workshop. To make a long story short, he said that a 180gr 10mm bullet at 950fps was just as effective in 10% gelatin as the Norma 170gr bullet at 1350fps. In addition, many FBI agents (who are primarily accountants, attorneys or computer people by training) were found to be having a very hard time with the recoil of the full-power round. Since the lighter round was just as effective and was easier to handle, the "FBI-Load" became the new standard of 10mm ammunition. Due to the huge market for law enforcement ammunition, most companies switched over production to the "FBI Load". In the mean time, Smith & Wesson realized there was an opportunity waiting. They realized that they could squeeze the FBI-Load's performance out of a cartridge short enough to fit in a 9mm sized firearm, rather than the 45ACP-sized pistols the 10mm required. They designed the 40 S&W in short order with the help of Winchester Ammunition, and the 10mm began to look very much like an ugly duckling again, as it had after the demise of the Bren Ten and before the Colt Delta Elite came out.

But of course the bottom line is get what you like best. For me it is .45acp :)

PBIR.  Nothing personal, but in the interest of a similair test, try getting velocities and energy figures with comparable bullet weights.  Again, I don't have my reloading manual so I can't look this up myself.  And dude... Be calm!

Speer doesn't make a .357 mag load heavy enough or a .45acp light enough to do that unfortunately. And I'm calm, calmer than you dude </Walter Sobchak>  

Well.  Like you said.  Personal preference.  Thanks for the data though.  

Well I have a USP45 and a USP40C. I keep the 45 by the bed at home and use the 40 for carry for a few reasons higher cap, and beter penitration, if it turns where the bad bad man is hiding behind something I have a better chance of getting my messanger threw to him... but in my house I want a faster stopper, and the 45 I feel will do that.

Since you are in Cali and poor poor guy has no chance of a legal CC go with the 45...

A legal CC? You mean a CCW? I can get one without a problem in my county...?

This sounds like its more personal preferance than anything. I've never shot a .40 so I guess my main concern is the .40s recoil over the .45.

I think I'm leaning toward a USP .45c and a USP .40F. Then maybe later if I like the .45c enough I can get a USP .45F.