Looking for a way too speed load PTW Mag's?

[CDN_Stalker]

Originally Posted by Danke

I thought that was a picture of a Martini glass!

With little black olives.

[Blackthorne]

Originally Posted by wKnight

I think your friend may have gotten lucky. I have noticed this effect on mags that have been accidently left fully loaded over an off season. the first game back they are unreliable and feed like crap. After leaving them unloaded for a while the problems goes away. But I deffinitly wouldnt want to keep doing it over and over again as it clearly causes issues.

I think springs wear out by holding the fully compressed position because this is not the memory position for the metal.

None of the guys I shoot with has ever had an issue. Now granted they are 5.56, not 7.62, but I doubt that would make a difference. (I assume 7.62 for hunting as you said "off season")

I have had my AR mags loaded for 6-7 months after a shoot (28 rounds) and never had an issue, mind you, they were in my nice dry cool ammo locker. (but filthy from the shoot none the less)

Originally Posted by Tankdude

It is called 'creep'.

http://en.wikipedia.org/wiki/Creep_(deformation)

enjoy some reading.

Maybe you should have enjoyed some reading.

Originally Posted by WIKI

Generally, the minimum temperature required for creep deformation to occur is 30-40% of the melting point for metals

Most stainless and spring steels melt around 1500C. So 40% of that is 600C.
Not anywhere near normal storage temps, even in hot climates.

Even in the crappy material used for airsoft springs, I doubt creep would be an issue.


SORRY FOR THE THREAD JACK!

[Blackthorne]

Originally Posted by Tankdude

That part is not true. It is a wiki for god sake. I can go change that number at will.

So what part of it is true then? Just the stuff that supports YOUR side of the argument?

C'mon man...

[Manchilada]

"While measurable creep can occur at low temperatures over very long periods of time or at very high (compressive) loads, creep usually becomes of engineering importance above about two thirds the melting point (absolute) of an alloy."
-The CRC Handbook of Mechanical Engineering

[Tankdude]

See the formula. Do you see a dirac or heavi side function there? No? Says creep will happen at every temperature. It will happen faster at high temperatures true, but it is not a magic number that says at 500 degrees start creeping, but at 499 don't.

[Manchilada]

Then your issue within my above quote is where they say "engineering importance". It is clearly stated that creep can occur at low temperatures, but whether or not it is of significance... I think I'll side with Dr. Frank Kreith, Professor Emeritus of Engineering at the University of Colorado and D. Yogi Goswami, Ph.D., P.E. over Tankdude.

[Blackthorne]

Originally Posted by Tankdude

See the formula. Do you see a dirac or heavi side function there? No? Says creep will happen at every temperature. It will happen faster at high temperatures true, but it is not a magic number that says at 500 degrees start creeping, but at 499 don't.

Agreed, but you are talking about creep that won't amount to a malfunction in a mag over a period of years.

It would be more likely to experience oxidation in the materials of the mag and ammo that would cause the stoppage, not weakness in the spring.

That kind of stoppage is solved with a good whack.

[Tankdude]

correct. The worst it will do is that the bb's will come out a bit slower.

Manchilada, that wasn't directed at you.

[wKnight]

all i know is what I have seen man. I have seen it with old mags, and the example i spoke of was left fully loaded for about 4 months.

But I have 2 questions about the above formula argument. Based on the other metals used by Asian gun makers in our AEG's why would we assume that the spring in the mag is steel? Its probably some crap ass cheap monkey metal. I have no experience with real AR's so I can't comment. But I would guess that they are very well built and thus can take more abuse.

Also, if you are dealing with a locap or, even worse, a midcap style mag where you have lots of turns in the BB track could this not have an effect? less force applied to the BBs could result in jamming around a corner. AR mag springs just have to push streight up.



edit: In addition, I am assuming that systema mags are made with much better metal springs than a regular AEG mag. But the spring is still very small, very long and has to negotiate several turns.

[leblanc74]

I use a HiCap TM's speed loader that I beleive holds 400 something BB's, I directly transfer from the loader to the mag, each push gives me around 4 BB's...