MP 45 Plus?

tommy F

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Anyone running plus or super loads in an MP45? Can they take limited heavy loads?
 
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The M&P 45 will handle +P as a defensive round but I wouldn't use it regularly. I wouldn't suggest you try +P+ or .45 Super in it. There has been talk of conversion kits for .45 Super but I don't believe they have materialized. 460 Rowland kits haven't happened either. The M&P can probably take the loads but why take the risk.
 
+P is fine but the only 45acp moder polymer handgun that can handle 45 super with nothing more than a spring change is the HK USP 45
 
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You will have to bump up the recoil spring weight but as ATF asked . Why take the risk. Buy some underwood P+ if you want a little hotter than other P+ loads .
 
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From the manual:

“Plus-P” (+P) ammunition generates pressures in excess of the
pressures associated with standard ammunition. Such pressures
may affect the wear characteristics or exceed the margin of safety.
Use of “Plus-P” ammunition may result in the need for more
frequent service.

“Plus-P-Plus” (+P+) ammunition must not be used in Smith &
Wesson firearms. This marking on the ammunition designates that
it exceeds established industry standards, but the designation
does not represent defined pressure limits and therefore such
ammunition may vary significantly as to the pressures generated
and could be DANGEROUS.
 
And plus p plus was used in s&w handguns over the years as in Winchester and federal Law Enforncement only 115gr and 124gr +P+ .

Can it be dangerous in some handguns ?? Sure and some even today are not +P rated . But 45 super is a whole different critter in some handguns .

Then again we still have KaBOOMS with some of the junk standard pressure that gets by what serves as quality control out today .

Simple rule of thumb If your barrel does not offer full chamber support Don't shoot hot ammo in it and do a plunk test . 45 super in a m&p !! Go find a s&w 4500 series to play with or a solid forged lower 1911.
 
M&P guns (Military & Police) should be good for NATO ammo because that's what the military uses. NATO specs are generally in line with +P pressures around 10% greater than standard ammo. The only handgun round currently specified by NATO is 9mm but of course the more powerful ammo you use the more wear on the gun. As Hardluck says above a fully supported chamber is essential for high pressure rounds the M&P 45 does have a FSC but what is the barrel pressure rating? I'm sure you would need to buy a custom 45 Super barrel and a heavier recoil spring. I'm not a fan of pushing the envelope so I would suggest get the right tool for the job.
 
With the track record the standard .45 ACP in 230 gr. configuration has complied over the last 100 or so years, I can't see a need for jacked up pressures and velocities in a defensive handgun. I have a full sized M&P 45 that has ate a lot of rounds, some of them +P, and its seems no worse for wear (other than the black anodized striker breaking at around 7500 rounds and a lot more striker drops during dry fire). While excessive use of a +P+ may or may not blow the gun up, there will no doubt be increased wear and tear, and likely some parts breakage at some point or another.

I probably wouldn't hesitate to use 9mm +P+ on a limited basis thru an M&P 9, as I have also shot a bunch of them thru a G17 and 19 with no ill effect. Nevertheless, last year, I saw a guy's ultra-compact, single stack, DAO semi auto manufactured by a reputable American company basically Kaboom with +P and +P+. Since it was brand new, it digested around 300-500 rounds of +P FMJ training and at least 100 rounds of +P+ duty ammo before the barrel split chamber to muzzle, blowing out the dust cover and bulging the slide. Because of that, I would recommend adhering to the manufacturer's warnings about higher pressure ammo for most handguns.

Besides, the M&P 45 is not only a pleasant and rewarding pistol to shoot with standard 45 ACP ammo, but it is also a very effective defensive weapon when the shooter does his/her part and places rounds where they are effective.
 
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Why are so many seemingly obsessed with +p, and +P+ ammo?

Randy

I ask myself that same question, every time I see one of these threads :eek:

If a "standard" cartridge does not meet your needs, then I would think you need to look at a "magnum" type cartridge; instead of pushing a standard cartridge beyond it's intended limits. With so many choices available, something should meet your needs without resorting to harm to your firearm or to yourself. :rolleyes:
 
Many of the same guns chamber in 45 are also offered in 10mm today. I asked the question to explore what other are doing. FYI I shoot more reduced loads than heavy, however some of the 45s acquired lately are huge in size (MP, 4506,XDM) and new technology
 
Why are so many seemingly obsessed with +p, and +P+ ammo?

Randy
Because the standard .45 acp load delivers ultra low muzzle energy to case capacity ratio?

Just because I know that high muzzle energy in a lightweight gun is bad, does not mean that the huge .45 acp case ceases to beg me to load it to 850 foot-pounds of muzzle energy. So, I stick with .460 Rowland in full size all steel 1911, and hot Underwood .40 S&W in the 40 Shield and 45 Super in Commander size all steel guns, and hot loaded 10mm in G29, instead of yielding to strong temptation to load .45 Super brass to 850 ft-lbs and shoot it in a small .45 gun.
 
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I shoot .45 Super in my Glock 21. Changed to extra power recoil spring, fully supported after market barrel and .45 Super brass cases.

Gun shoots well and with this setup I can still shoot normal pressure rounds.
 
Many of the same guns chamber in 45 are also offered in 10mm today.

Most factory 10mm is castrated in power level. I'm not impressed in having to drop to a 18# mainspring to run factory 10mm. If the gun is sprung the same as a .45, it's a long .40 and not a 10mm. The Glocks really ought to be better sprung, but they're getting away with it somehow.
 
With the track record the standard .45 ACP in 230 gr. configuration has complied over the last 100 or so years, I can't see a need for jacked up pressures and velocities in a defensive handgun.
I completely agree with this statement.

Why are so many seemingly obsessed with +p, and +P+ ammo?

Randy
I don't think obsessed is the right word. I think people just want the most effective round they can get. What most don't realize is that +P and hotter pressures don't increase the effectiveness of the gun.

Test after test, study after study has shown that shot placement trumps all. Caliber, muzzle velocity, knock-down power, etc., matter very little in the grand scheme of things. It's not hard to find self-defense situations where a .22LR was used to kill the bad guy. It's all about where you put the bullet. Since placement is king, the next thing I want is ability to control the gun. Greater pressure loads make it more difficult to control. Can you do it? Sure, but why?
 
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