Magnesium AR lower

[eodinert]

When firms make a lower that is not forged, but cast, they tend to catastrophically fail.

Like whose? Do they fail because they are cast, or because they are poorly made?

[thei3ug]

It's inherent in the process, not a quality issue.
Magnesium being a different material, there may be some material differences, but aluminum castings have proven to be unsuitable for AR receiver parts and when people see it used alarms go off.

[Shao]

Let your barrel rust completely away, grind that and your lower into very fine powder, and then light it with a strip of magnesium. That's what it takes to kick off a thermite reaction.

Not just magnesium, the spark from a lighter or even a Fourth of July sparkler can set it off.

When firms make a lower out of alternative materials, they more often than not have a tendency to catastrophically fail. When firms make a lower that is not forged, but cast, they tend to catastrophically fail.

Not doubting you, but are these cast lowers? I can't seem to find any info on the manufacturing process used to make these. If so, then that would = major fail. If that were the case I would imagine these would be maybe just a step up from a Zamak lower.

[thei3ug]

People have uploaded photos showing flash around pin holes and ejector pin marks on the pistol grip area. The Gen 4 models machine out the section that had the old pin marks. In addition there was a run on sentence on their website that mentioned cast. The edges look very much like molding.

[thei3ug]

The reinforced takedown pin holes are another clue.

[Heavy Metal]

I wonder if Magnesium would work in a non-cast application?

[Shao]

Titanium MMC is where it's at... in maybe 20 years...

[foxtrotx1]

Not just magnesium, the spark from a lighter or even a Fourth of July sparkler can set it off.

Derail: Sparks won't start the reaction. You need at least 1250c heat source. the AE is too high. I have always used a sparkler for the convenience.

[Shao]

Derail: Sparks won't start the reaction. You need at least 1250c heat source. the AE is too high. I have always used a sparkler for the convenience.

I guess this experiment from the University of Minnesota is a hoax then?:

http://www.chem.umn.edu/services/lec.../Thermite.html

N/M.. answered before you edited your post.

[foxtrotx1]

I guess this experiment from the University of Minnesota is a hoax then?:

http://www.chem.umn.edu/services/lec.../Thermite.html

N/M.. answered before you edited your post.

Why is it a hoax? i'm confused. Sparklers generate an immense amount of energy, well over 1200 Celsius. Sparks from a lighter may get hot enough, but not for long enough to initiate the reaction.

To relate this to the thread: You will not ignite your magnesium lower without a sustained heat of high intensity.