Is your AR gassy? Find out here...

Is your AR gassy? Find out here...

Welcome back to the 12th installment of my blog, in which I don’t claim to be an expert, in fact the very opposite. I’m a new user to the AR platform and want to share my findings and experiences as I go through and build rifles as well as being the Operations Manager at Tyrant Designs.


Thanks for tuning into another fun, educational and overall bad ass blog post. Today we will get down and dirty on some different AR-15 gas systems. Not the most sexy of topics, but it’s important to know how your rifle operates. If this doesn’t interest you, start your own blog! But seriously please keep reading my job depends on it.

 AR-15 Tyrant Designs CNC

How does an AR function?


Basically, all AR’s must be able to function mechanically without the user doing much more than pulling the trigger. The rifle must be self loading, meaning that every time the trigger is pulled it needs to be able to fire the cartridge, extract the casing, and load another round from the attached magazine.


The original gas system


The original gas system that equipped AR’s is known as Direct Impingement. The gas generated by the explosion of the round gets directed to a small hole in the barrel. This gas then goes through a skinny tube and directly “impinges” on the bolt carrier and travels to the rear of the rifle. This extracts the spent cartridge and is pushed back by the bolt carrier spring, which at that point, the bolt carrier mechanism takes another live round from the magazine.


The newish gas piston system


The main difference between direct impingement and a gas piston system is that the piston system does not force the gas into a small tube. It actually gets directed to an entirely separate cylinder. In this cylinder there is a piston which pushes the bolt carrier back to start the ejection process.



Which one is good for you?


Notice how I didn’t say which one is better right? There is two sides to every gas system.


The direct impingement system is definitely reliable. It’s been around as long as the rifle itself which has been time tested with both civilians and our armed forces. Also the parts are easy to replace and are not expensive. However, because of the direct heat being in contact with the action it tends to get dirty, so keep it clean.


The piston system actually keeps the action cool. If you wanted, you could remove the bolt carrier after firing multiple rounds and you’d be able to hold it in your hand. In some people’s experience they notice more recoil and inaccurate follow up shots from the action not being warm. Also, the piston system can be pricier and there are not as many standards that make them interchangeable between different manufacturers. Thats more or less all I have for you this week. Stay tuned next week for some other crazy cool stuff that you'll need to read.


If you made it this far we are now best friends.

2 Responses

Gregg Rock
Gregg Rock

April 08, 2017

Cory, newbie here also. What is a “bolt carrier spring”. TIA

Tony Carter
Tony Carter

April 07, 2017

Gas for now but looking at the M27…….

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