What is the difference between piston and gas ar 15

I taught the M for years. Nevertheless, DI is cheaper and lighter, and if you plan to build or modify your rifle, the DI world is full of parts and options. You can run a hundred rounds through it and have less grunge than 20 rounds through a DI. So if you want a low-cost option, stick with DI. Your email address will not be published. This site uses Akismet to reduce spam. Learn how your comment data is processed. Need Assistance? Account Login. How it works. Gas Piston AR system. The animation below shows a basic visual representation of what happens.

There are some great videos out there to help with this process Here: So which one should you pick? Image Courtesy of: DefenseReview. My Account. Stag Arms Blog. Direct Impingement — How do the original AR models work? Gas Piston Technology — How do the new piston technologies work? Which system is better?

Subscribe to Email Updates. Recent Posts. The DI guns that are that cheap are junk, and you can get a reasonably priced GP or DI gun for about the same price now. If you do have an adjustable gas block, and you dial it down until it gets to the same level of blow-back as a GP gun, it will not function — by its inherent design specifications…hence the need for products like the Gas Buster charging handle.

Anyone with half a brain has their own spare parts for any gun intended for a long-term survival survival situation anyway. Personally, I keep a fully assembled bolt, a couple more firing pins, lower parts kits, pins, springs, etc.

It will be for a functioning gun…or guns. A DI AR exerts a linear force on the bolt, gas pushes forward and rearward from the chamber inside the bolt carrier. A piston adds a lateral force to the system, pushing on the top of the carrier. This causes the tail of the carrier to tilt down, as the only bearing surfaces are from the centerline forward.

HK tried adding material to the bottom rear of the carrier, to fix this. The other force, induced by a piston, is rotational. As the carrier is jammed to the rear, it tries to rotate against the cam pin.

Never seen a DI gun with an adjustable gas block. Most every piston gun I have seen or owned has gas valve specifically for this purpose. I would say time will eventually tell if the new piston driven systems last mechanically as long as the older gas impingement systems. I think too that the gas piston systems are the result of reverse engineering which in the past has proven to be an inferior way to design a firearm.

If I wanted or needed a reliable survival rifle it would be either the AK or the M14 both of which are much more reliable and powerful as opposed to the AR15 and its anemic. I cannot believe you stated that you would use the gas impingement system AR15 as it is no more reliable today than it was in Viet-Nam.

I have plenty of experience shooting large numbers of rounds through this inferior system and it is the last gun on earth I would use if the chips were down. Never seen one? Do you ever check the parts sellers on the internet? There are probably more than 20 manufacturers of adjustable DI gas blocks. Primary Arms sells 19 different types. You need to get out more, or get a pizza and surf the web for gas blocks.

Hmm — I built both a 5. Save my name and email to use for future comments. This site uses Akismet to reduce spam. Learn how your comment data is processed. Forgot your password? Get help. Password recovery. Gun Digest. Gas Piston. Well, each carries its own sets of benefits and drawbacks that can affect your shooting style, as well as your personal preference. And finally, direct impingement systems are more affordable than piston-driven counterparts, giving your wallet a break.

But there are some potential drawbacks to gassing up your gun, the main one being reliability—particularly with a non-standard or shortened barrel AR, or any select-fire models.

Since timing is essential when it comes to releasing the proper amount of gas into your gun, shortening the barrel or gas tube, for example, can lessen dwell time while causing case extraction problems, leading to jams.

This, coupled with timing issues, brings into question problems of reliability among direct impingement systems. There are many pros and cons of piston-driven rifles, with their main benefit being reliability. And, since the operating rod does a lot of the work, rather than the gas itself, it promotes a cleaner, cooler system that better handles the intensity of firing a round.

Also, the piston adds extra weight to the back end of the AR and tends to cost a little more than the alternative. If you own a gas piston AR, for example, you can install a piston-driven upper receiver — and both direct impingement and piston-driven systems work independently of the lower receiver, allowing you to switch between the two mechanisms.