Yay they're cheap!
When selecting your Freedom loving firearm to defend your land, nation, or self, you need to be wary of the cheap guns floating around. Right now there are version of the AR15 that are cheaper than they've ever been. This is very exciting to people that are not "in the know" and very terrifying to those that are fully familiar with the platform. Details Matter.
So whats the difference between a cheap AR15 vs a premium AR15, and why does it matter? Well there are many differences, but today I'll cover the most obvious and easiest to understand.
The Gas Block
The Gas block is one of the most important parts in the AR15 platform. The Gas Block is the part that collects the propulsion gasses from behind the bullet and funnel them into the gas tube. The gas tube is what then directs the gasses onto the "gas key" in the Bolt Carrier Group. This is where the magic happens. The gas expands at the gas key and then forces the entire Bolt Carrier Group to cycle. This ejects the spent round and feeds the next one. If the gas block is leaky, the rifle will experience something called "undergassing".
Undergassing
Undergassing is a condition where the bolt carrier group moves too slowly to properly cycle. This can be caused by excessive dirt, debris, lack of lubrication, underpowered ammunition, improper tuning (Buffer too heavy, Action Spring too powerful, gas port drilled to wrong spec), or most commonly, a leak in the gas system.
Aluminum Where Steel Should Be
Don't get me wrong, Aluminum is a fantastic material, when used as intended. However if you replace a part that was engineered to be made of a durable material, with one that is lightweight and not quite as durable, the yield is undesirable. There's a reason why there are very few (if any) automobile manufacturers that use aluminum headers. Aluminum, although a great conductor of heat, is not very durable at high temperatures. On an AR15, the hot propellant gasses will continuously erode the gas block until they poke another hole in the gas block. If you're lucky, your gun stops working. If you're not lucky, you'll feel a rather unpleasant sensation on your hand. If you're really unlucky, you'll have a "copay"
That’s Long Term, I don’t need it forever.
Durability is a long term problem sure, and some people say "Well I'll just keep it for my prepper kit and hope I won't need it long term." Sure, some people think that way, however the reality is, they're not very good in the short term either. Steel and Aluminum expand at different rates. Typically, aluminum gas blocks expand about 30% faster than the steel barrels. The result is a leaky gas system and a gun that won't cycle reliably once it's hot, and it won't cycle at all once it's hot and dirty. Now imagine, you’re in your post-apocalyptic word that you’ve been preparing for, and now your rifle doesn’t operate reliably when you need it most. Was the extra back then worth the struggle you’re about to face? Probably not.
How do I know if it’s steel?
If you trust your dealer, ask. They should know. If they haven’t a clue, be prepared with a magnet. Aluminum gas blocks will not stick to a magnet, and if they do, the draw will be very weak. A good steel gas block will grab that magnet every time.
What about titanium?
True, titanium offers the weight savings of aluminum, and the durability of steel, however the cost is about 5-8x higher and not likely worth it.
Brand Name
Be careful with AR15's from "Big Brands". The truth is a lot of these brands are not owned by the people or families that started them long ago. Now they're all about cheap guns and expensive marketing. They'll save a penny anywhere they can and the customer is who really pays the price in the long run. Do your research. If you need a place to start. Checkout the HD Defense Genesis. It's a fantastic foundational carbine that uses quality components, is sold at a fair price, and comes with no gimmicks. Just a quality American Made Firearm.
Don’t be cheap.
In closing. You don’t need a $2000 carbine to defend yourself, but a few extra hundred bucks, spent wisely can really go a long way.