Years ago I had a friend with an operational MP40 under a Class 3 license. I never got to shoot it, but he pointed out that if you grabbed the magazine as the natural grip on the front of the gun, it would begin jamming. There is enough play in the magazine well to shift the feed angle enough to cause misfeeds. He said the German army taught users to grab the magazine housing above the actual magazine, and holding it there you'd get close to 100% reliability. Since then I've read accounts of GI's playing around with MP40's and dismissing them as jam-o-matics, which made me wonder if they were hanging onto the magazine as they shot it. An interesting fact about the 9mm in general is that a pistol sighted in at the normal 15 yards (meters) will fall back to that point of aim at 100 yards/meters, or pretty close. It's kind of like a billiards trick you can use to impress people when shooting at a range. People will think you're a hot shot if you say "Hold my beer and watch this" then ring a gong at 100 yards. Nobody else will be able to do it because they'll naturally hold several feet over the target instead of aiming directly at it. That only works with the standard 115 grain slugs, I don't know where the 147 grainers land. Just kidding about the beer!
About a year or so ago I read a news story of a house in Holland being remodeled. When they tore out one inner wall they found an MP 40 with several filled magazines. Not only was smg functional, the magazine springs still had their "spring". When you think of it, it's almost scary.
If you compress a magazine spring, it will retain its strength. Or, if you leave a mag empty the spring will retain its strength. It is only the repeated filling and emptying of magazines (compressing and releasing the spring) that weaken it. Most people don't understand that and thus are afraid to store their mags loaded. That info comes from Wolff Gunsprings and is aimed at people who carry a gun every day (cops, mostly) and then empty the mag every night thinking they are protecting the spring from wear. In fact, they are reducing the life of the spring and risking a failure when their life is on the line.
Not really to me. It's not like it was going to jump out of the wall and start shooting someone. Were the house to have caught fire, that might be different concern. The main worry would be a chambered bullet. The others would just pop off, and are not expected to cause great injury. Mythbusters covers it pretty well Mythbusters - Bullets Thrown Onto Campfire - Are They Lethal? - YouTube I am a volunteer FF and have fought house fires where we could hear ammo cooking off inside. It is still unnerving.
This was a common matter during the war. Weapons had to be ready in case of a surprise attack. The MP40 was probabably left behind at the liberation and then either forgotten by the Dutch owner or hidden there . Believe it or not, but a common hiding place was the upper part of a fire place (without amno of course) .
According to Wolff Gunsprings they don't. It's a myth. They've been making and studying gun springs for 30 years, so I tend to believe them.
I think that needs a bit of qualification. A spring that is over compressed may take a set. Depending on the spring (just what aloy and how it was heat treated) that may include magazine springs with a "full" magazine. Much more common with older springs as advances in metalurgy have been significant in the last few decades which would cover the statement by Wolff Gunsprings. I'm not sure I would trust a Chinese, Indian, Pakistani, or other third world spring not to "take a set" though.
I'm surprised by this, even the .50 cal ammo wasn't lethal in a fire. Love those Mythbusters, they probably have one of the best jobs in the world. I figured the best place to start posting again was an mp40 thread.
I could even post a link to................................................ http://www.ww2f.com/wwii-films-tv/15785-mp40-project-reborn.html ........................................
There is probably no one even casually interested in World war 2, that has not seen this weapon pictured in the hands of some German soldaten or SS trooper. Without going down the rabbit hole of small arms history too far, all combatants during the war at some point, decided they needed a cheap submachine gun to arm their troops with as may guns as possible made as quickly as possible. The Russians had their PPSH which was dead reliable but crude beyond all measure; the Americans had their Thompson, which proved to be too expensive and was replaced mid-war, about 1944, by the much cheaper M3 (the grease gun) and the British had their famous, or infamous "stench gun" which was hated and despised by more British troops then maybe any other weapon of the war (it jammed a lot). The Germans alone had a really good sub gun to begin the war, the MP38. The Mp38 had a lot going for it, besides the cool factor - it was easy to field strip, had possibly the world's first practical folding stock (making it the ideal weapon for tank crewman and paratroopers) and as a result was compact and fairly reliable (as described above). However, like the MG32, it had the fatal flaw in wartime of having too many machined parts, making it too hard to manufacture. So soon, the Mp38 was superseded by the MP40. The MP40 looked exactly the same, and even shared some parts. However most of the MP40's parts were replaced by steel stampings, so except for the barrel and bolt, the expensive machined parts were done away with. Over 1,000,000 MP40's were made during the war (I forget how many MP38's) and these were mainly issued to tank crew, NCO's, and officers who needed a compact and light weapon but something more then a pistol. To hit anything at much more then 100 meters would have been a feat, as the weapon, like all other sub guns of the time, fired from an open bolt. This meant the bolt stayed back when the trigger was released.
Not surprising at all if you know a bit about ballistics. A firearm relies on the tight confines of the barrel to ensure that the pressure all goes out in one direction: toward the target. When you've only got a little hole less than 10 millimeters wide for the pressure to escape, it tends to rush very quickly out that one hole; the expanding gases of combustion can be likened to the steam from a tea kettle, but in one instantaneous burst instead of a continuous stream. Without the barrel to focus that energy, it goes in every direction as soon as it leaves the mouth of the casing. Even a .50 BMG round doesn't actually have a whole lot of raw explosive power inside of the casing; without a barrel to essentially concentrate the expanding gases into the necessary pressure and direction, it's barely a cheap firecracker. The bullet won't even be pushed out with enough force to shatter thick glass, let alone kill. That's also why shorter barrels give you more flash and boom, but less power: the MP5K gives a bigger fireball than an Uzi (I've tested both, so I would know) and has a louder bang, but its intimidation factor is offset by lower power and range. That flame and blast from the muzzle is all of the wasted energy dissipating relatively harmlessly (if spectacularly) into the air, as the barrel is too short for it to all burn up. Shorter barrel means less velocity, meaning less power and range. The Arisaka Type 38, when made into a sniper rifle, was actually very efficient despite its low caliber compared to .30-06: its barrel was just long enough for all of the powder to burn and push the bullet to its maximum velocity before leaving the barrel, which gave it as much power and range as could be squeezed out of the 6.5mm cartridge while having relatively little noise and almost nothing but a tiny puff of smoke and a small flash at night to see. Counter-sniper activity, to put it simply, was a bitch.
There's actually a website devoted to the subject of barrel lengths and velocity: BBTI - Ballistics by the Inch :: Calibers/Cartridges With the 9mm and standard 115 grain slugs you seem to get a max velocity at about 12 inches and after that it doesn't change much. It's more interesting at the lower end of the scale where some of the short barrels (as in the new mini concealment handguns) really don't have much steam compared to service pistols of 4 to 5 inches. The MP40 had a 10 inch barrel (251mm) so has pretty good ballistics.
The big reason pocket pistols remain in small calibers like .380 ACP is because the shorter you get, the harder it is to handle and the more power gets wasted. A 9mm small enough to fit in your pocket has a lot more blast and noise and more violent recoil than the same caliber in a full size gun, but doesn't have enough power to justify the added discomfort and lower capacity. Better to get something that's comfortable as well as compact and hits well enough for self-defense than trying to fit too much gun in there.
