how many rounds per mag for home defense

[Loaded1985]

Ive got an HK with 4 mags. the mag that is currently in the gun is full (8 mrd mag) 8 rounds in it. how about the other 3? should i only keep 7 or are HK mags good enough that i can keep them full without being worried i damaged the springs? wats your opinions?

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[huntpotter]

I usually keep 1 mag loaded all the time, but rotate it out every couple weeks. Unload it, and load up a new one. That way it won't wear out as fast. HK mags are as good as any other brand. Springs by nature will wear out eventually. That's just my thing I do.

 

[eriknemily]

From what I've been told (by OFA instructors) is that mags should be kept fully loaded or completely empty. I carry and M&P and keep two mags full and keep the third one empty. I'm not sure that it would really make a big difference over the life of the mag whether or not you keep it loaded or not.

 

[wichaka]

I leave 3 mags fully loaded and rotate them 1-2 times a year.

One doesn't need to rotate them very often.

 

[candyman]

I leave 3 mags fully loaded and rotate them 1-2 times a year.

One doesn't need to rotate them very often.

what he said only i keep 1 in the car also

 

[eddieb]

Mag springs weaken from the spring being compressed and expanded. Either leave it compressed or leave it expanded and you'll be fine. Think about what happens when you take a piece of wire and start bending it back and forth. It will weaken and break. But if you leave it bent, it will stay bent and strong forever. So you can leave your mags loaded all the time and not weaken the springs.

 

[gunnoob75]

Depends on the mag!

I have nice mags loaded with Gold Dots for my 1911. Two of them loaded at all times. Then I have some cheaper one's that I use for FMJ's. (Range ammo).

But, I also have a bunch of AR mags loaded. Four mags in the gun case, loaded to 29 rounds each. And five in my vest, loaded to 29 each. Plus one in the gun, that is 28+1.

I'm not paranoid, I just don't like loading and unloading magazines.

 

[dario541]

Remember this about springs: The valve springs in automobile motors are ALWAYS under compression. When you drive, these springs are being compressed further and released (flexed) thousands of times per minute. There are cars on the road that have been driven for 50 years and more. They never seem to have trouble with these springs. I don't think that good springs will lose their "memory" if kept compressed.

 

[Loaded1985]

thanks for all the info dudes!

 

[A2theK]

Depends on the mag!

I have nice mags loaded with Gold Dots for my 1911. Two of them loaded at all times. Then I have some cheaper one's that I use for FMJ's. (Range ammo).

But, I also have a bunch of AR mags loaded. Four mags in the gun case, loaded to 29 rounds each. And five in my vest, loaded to 29 each. Plus one in the gun, that is 28+1.

I'm not paranoid, I just don't like loading and unloading magazines.

"And five in my vest, loaded to 29 each. Plus one in the gun, that is 28+1".

Is that trailer park math?

Sorry - Had to get a shot in...

...or do you mean you keep a 28rd mag in the gun and 1rd in the chamber?

 

[JUSTIficatioN]

2 mags, one is loaded and they get rotated every month or so, i usually keep one shy of a full mag because i dont want the added tension on the spring. but is tension something i really need to worry about? or am i just shorting myself?

 

[SavageGerbil]

If you're concerned about it, its a great excuse for a trip to the range for testing, pick up some extra spring kits from Wolff or someone, always good to have. Standard better to have it and not need it arguement

 

[Gunner3456]

Remember this about springs: The valve springs in automobile motors are ALWAYS under compression. When you drive, these springs are being compressed further and released (flexed) thousands of times per minute. There are cars on the road that have been driven for 50 years and more. They never seem to have trouble with these springs. I don't think that good springs will lose their "memory" if kept compressed.

Exactly. And when you stop the engine, some of the valves are fully compressed and stay that way until the engine turns over again. Almost every valve is in a different state of compression.

Engine valve springs do wear out to where they test weak on a valve spring tester (and can allow a valve to burn because it doesn't close fully or fast enough,) but by then the rest of the engine is usually also worn out.

Valve springs don't even enter the conversation until there is a valve grind, performance cam upgrade, or engine rebuild, and then they are tested. Most used valves will be within specs and can be reused if desired.

$.02

 

[gunnoob75]

"And five in my vest, loaded to 29 each. Plus one in the gun, that is 28+1".

Is that trailer park math?

Sorry - Had to get a shot in...

...or do you mean you keep a 28rd mag in the gun and 1rd in the chamber?

28 rounds in the mag, and one in the chamber.

Bad use of a Comma on my part, I think.

 

[raindog]

Mag springs weaken from the spring being compressed and expanded. Either leave it compressed or leave it expanded and you'll be fine. Think about what happens when you take a piece of wire and start bending it back and forth. It will weaken and break. But if you leave it bent, it will stay bent and strong forever. So you can leave your mags loaded all the time and not weaken the springs.

+1 - that is what I have consistently read, too.

 

[Gunner3456]

OK, enough.

A properly engineered spring will not fatigue if left either compressed or uncompressed or even partly compressed. In layman's terms that means the spring stays static within the yield strength of the steel.

To further simplify, if the material is made to exceed its yield boundaries, fatigue crack nucleation can occur at grain boundaries, second-phase particles, twin boundaries, and other microstructural areas. With me so far?

Because it is "cyclic loading" which causes spring fatigue failure, a static spring maintained within its yield boundaries will not be altered unless it is defective.

Fatigue is not a bending type failure. It consists of crack nucleation/initiation, progressive cyclic crack growth, and catastrophic failure. Fractographic examination of the material commonly shows "river markings", i.e. ridges or striations which delineate the cyclic crack propagation.

So there.

 

[servingu]

yea what he said

 

[powersbj]

Iv had a kahr e9 for 11 years now always fully loaded (only own 1 mag), shot +/- 2k rounds through it and never had a single issue. So in short if you own 4 mags use one until it wears out and then tell us how long it took cause I've yet to get there.

 

[clearconscience]

unless your using cheap mags I don't think it matter, HK are great mags and shouldn't have nay spring problems, having said that I would keep at least 6 mags as high cap as you can get, keep half them full and swap the other half once a month or so.

 

[Gunner3456]

Leaving a spring in one position whether compressed, partly compressed etc. doesn't effect it's life. It's moving its position which wears it out.

As long as it isn't stretched or compressed beyond it's design parameters, it will stay good "forever" fully loaded.

Compressing and decompressing a spring is called "cyclic loading" which causes spring fatigue failure. The "loading" doesn't apply to loading guns, it applies to any spring having a load put on it and then having the load released.

The more times a spring is cycled (cyclically loaded,) the faster it wears out. How many times that is depends on the spring.