.45 vs .40

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Aug 1, 2007
The Great Republic of Texas
Before this gets into a big caliber discussion, I'm really just wanting opinions about a specific pair of pistols. It looks like I am about to embark on a LE career, and will be purchasing my own duty weapon and the field of choices is left wide open by the department. I have narrowed my selection down to the S&W M&P in either .40 S&W or .45 ACP. There are advantages to both. Having a hard time deciding. I currently conceal carry a Taurus PT145 Pro, and shoot it well. I'm familiar and happy with the polymer striker-fired setup, and the M&P fits my mitt quite well. I have no problem with the hefty recoil, as either pistol will not be as harsh as my current carry.
Basically this: the .40 is a new caliber to me. I've shot it maybe once, and it's more than manageable. I love .45. But as an LEO, I'd really like to have the peace of mind of having 15+1 rnds (M&P 40) as opposed to the 10+1 I already have in my Taurus. I know the likelihood of ever reaching double digits in a gun fight is low, but always possible. There's also the length difference. The M&P .40 has a 4.25" barrel, whereas the .45 has the 4.5" barrel. Is this a noteworthy difference? (No, I have not shot them yet, and I intend to, but I know some of you have). Finally, I'll supply most of my own ammunition. Both are roughly the same price from what I've seen, but getting another .45 ACP simplifies my ammunition needs.
So whaddaya think? .45 or .40?
The new S&W M&P .45 also has the option of being avalable with a 1911 style thumb safety. That's a major plus in my book but opinions will vary. The .40 offers higher mag capacity but if that's an issue with you, the Springfield XD .45 offers 13 rounds. Barrier penetration also leans in the .40 S&W direction vs. the .45. As an LEO, that aspect becomes more important than it does to a civilian CCW. My pick? The S&W M&P .45 w/thumb safety. But if the M&P .40 was available with the same safety, the choice would be more difficult for me.
I'd go with the 45 if it were me.like you said simplifies ammo.but thats just me I'm kinda anti 40 :evil:
I'd go 45.

You are familiar with the 45’s recoil pulse and are comfortable with it. The 40 is a good round, but I think that the way (not the amount) it recoils is harsher and more abrupt than the way that a 45 hits your hands.

You can open carry as an officer (I am assuming that you will be a uniformed officer), so the .25” difference will be nil.

The 5 round difference is pretty large. I can’t comment on the importance of this as I have been fortunate enough to have never have the occasion to find out how important those extra rounds are. If this is a major concern, you may want to look into a XD45 or at the HK USP45. Both hold 13+1 and I can attest personally to the HK’s extreme reliability and durability.
I'd go with the 40 due to the barrier penetration factor, 40 is better in this category, which you might very well face in a LE situation. There was a story out of Texas a couple years ago of an officer with a 45 engaging a trucker who was waving a gun around, the 45 did not penetrate the cab of the truck, his partner, who had a 357 Sig, fired off a couple of rounds, they punched right through the cab and killed the guy. Just a case in point.
Well do you want to feel a push or a violent snap while shooting? They both will do the job well.
I too like the M&P 45. The sight radius is longer and the thumb safety is a plus in case of a snatch and shoot against you. If you already shoot .45 acp, another plus. Having 5 more .40s than .45s isn't a big factor in my book. Carry an extra couple magazines. What's your BUG going to be? .45 or .40? I'd carry both weapons in the same caliber, if the BUG will be an auto.:)
Capacity is a consideration as well as your ability to shoot it accurately. Can you test fire both weapons? What are other LEO's in the department carrying? Given the likelihood of having to shoot through a car door and/or windshield, I would opt for a .40 S&W and/or a .357 Sig. Since you mentioned the M&P 45 and the M&P 40, well I would go with the .40.

This must be a small department where your backup will be scarce and far away, given this, I would definitely get something with a bit more rounds than 10 just for that special moment. You may never need the extra rounds but who has a crystal ball? I don't. Nobody on a forum can tell you what is best, only you can decide which is better for you. As an LEO, I carry a .40 S&W and feel well armed. Is it the best, no, probably not, but it's the best for me.
This must be a small department where your backup will be scarce and far away
It's Richardson; a fairly large metropolitan suburb butting right up against Dallas. Most of them carry Glock, but I just can't get over the poor fit to my hand. They carry a wide array, including Beretta, HK, Sig, Taurus, SA, you name it.
The ergonomics of the S&W are ideal for me. I have a friend who will let me shoot his in .40, but don't know where i'll test the .45.
Glad to hear the opinion of a LEO. And glad to hear you feel well armed with .40. I had considered to great length the XD45, and still won't completely rule it out, just like the ergonomics a little better on the S&W.
My BUG? I've given this some consideration. I'm really not sure or even close to a decision. Thought I would carry the PT145 until I scraped together dough to buy something a little more sleek. I thought about even something like a Keltec, as many LEO's in this area seem to like them. But I do also have a Taurus 85 .38 Spl. that might be easier to lug as no. 2. I'm open to suggestion, as I'm fully aware the backup is best in the same caliber and same magazines if possible.
I am a LE Officer, and I know from very recent experience that the .40 is NOT a better penetrator than the .45. IF you have the option, and I didn't, to carry .45 caliber 230 grain hydo-shocks, DO IT. The heavier the bullet, the better chance it has of getting to the bad guy. I would've been better served by military .45 ACP ball ammo, than the .40 S&W hydroshocks that I carry now. Leave the .40 to those who are required to carry it.

Roll the dice, pluck petals off a daisy, consult the Urim and Thummin.

Just buy one. Either will do fine. More important that it fits you, you shoot it well and it's reliable.
I can't believe that a larger department doesn't provide the weapon and ammunition. That's why I assumed a smaller department. Opinions will vary when you talk about various calibers, so keep that in mind during your selection. Best of luck.
i honestly doubt there'd be that much difference in the performance of the two. I prefer the recoil of a 45, but you're weighing that against the capacity, and it's not like the 40 is so awful, and realistically it's not like you're going to be shooting it out every night with someone I assume. And in my experience, you don't notice recoil when you're actually shooting AT something in the field, only when practicing.

I wouldn't stress too much, either's a good choice. If the majority of your fellow officers carried one caliber or the other, you might go with that one figuring you could share ammo if necessary.
First off, welcome to THR. Hope you find a lot of valuable information here.

I have three M&Ps, including the 40. I don't have the 45 yet.

With that being said, the recoil of the .40 is not bad at all on this gun. I have a Glock 22 and it gives a very sharp snap of the muzzle. The M&P almost shoots as easy as the 9mm.

I would steer you toward the 40, but there are good arguments to be made for the 45. Personally, I'd just prefer the capacity. The ballistics are good enough (albeit may not blow his arms clean off like the 45 :p:D).

My advice? See if you can find a range that rents them both and give'em a test drive.

Aside from that, I recommend the 40.

Good luck with your decision.

ETA: If I may, I'd like to point you to a thread regarding the reliability of the M&P40 by one of our moderators (and fellow LEOs, I believe)
ETA: If I may, I'd like to point you to a thread regarding the reliability of the M&P40 by one of our moderators (and fellow LEOs, I believe)
That's one of the threads that sold me on the M&P, and The High Road. I stumbled upon it while researching this pistol, and liked what I saw. Loving all the info and getting to share America's most important hobby with so many across the US.
I like .40 more than .45 since it is cheaper. I feel either one will do the job when you need it to.

As a college student the budget takes a hit whenever I want to go shooting. Hence my preference for the .40 rather than the .45.

When I am done with school and get a real career I will get myself a nice 1911 in .45 as I love the platform.
ok, I've only read the first couple of posts on that M&P reliability thread, but in the first couple he's already had 7 malfunctions each, and that's a good thing?
You really can't go wrong with either choice. Though as someone before mentioned (and this just might make your decision harder) as a LEO you might want to look into 357 SIG, which i think can also be found in an M&P.
As for "barrier penetration" I'd rather have a .45 ACP sidearm and a .223 Remington carbine in my car when needed. The appeal of .45 ACP for me is that if all I have is FMJ/hardball or if my "expanding" ammunition does not expand, a 230 gr. .45 caliber bullet is still a good defensive round. I feel better, personally, having a bigger and heavier bullet when the fecal matter hits the rotating isolator.

If .45 ACP can't do it, you really need a long gun, not a .40 S&W or a .357 Sig.

I'd roll with my M&P 45 or Colt Combat Commander as a sidearm and my Lewis Machine and Tool AR-15 16" 5.56mm carbine.

Good luck with your new career.
Excellent. I'd also invite you to check out MP-pistol.com for more information on the M&P, just in case you haven't run across it yet. Lots of good information over there as well.

Also, fyi, there is a dude over there named Dan Burwell (warning - his site has a background color that will burn your retinas.) :D

He does a trigger job (and also posts the DIY directions) that makes the M&P trigger almost as good as a 1911 trigger, or so I read. I also really like his bead blast and shark stippling modifications. His work is top notch. Coronach (the author of the thread I previously linked) had the trigger job done, I think. He might provide further insight on it. I have not done it yet.

Be forewarned, the trigger on all three of my M&Ps have been very gritty at first. But they have all smoothed out very nicely after about 400 rounds.

Again, good luck with your decision and let me know if I can help.
it may have been mentioned here already I don't recall, but if you get a 40 XD, you can have a 357 Sig with a simple barrel swap.
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