AR15 Gas System and Buffer Basics

today we are talking about ar-15 gas system and buffer 101 [Music] hey guys my name is Dave Tim thank you very much for checking out this video we actually received a viewer request I was a social media comment asking about ar-15 gas and buffer type 101 you know what the differences are between the different gas systems for your air 15 and buffer basics so that's what this video is going to you know kind of dive into this is going to be a very basic kind of intro tech course to the gas system because truthfully it can be complex depending on a variety of things which will kind of get into and then will also start to talk about buffers just a little bit there are a wide variety of buffer products now on the market with spring systems different weights dampening products etc so we're not going to dive into all of that right now but we're going to scratch the surface and if we want to maybe do another video in the future where we get into more detail on specific products we certainly can do that now the ar-15 is a gas-operated rifle I'm talking about the direct impingement gun I know there are piston guns and I'm very familiar with a lot of those I used to work for a company that was in the piston rankle business but for the purposes of this video we're talking about direct impingement rifles which basically means we have a gas block a gas tube in a traditional bolt carrier inside the upper receiver that the gas is used to cycle the rifle now there are different things that affect the sight cycling of the rifle number one the cartridge itself the amount of powder the pressure the load that really does matter you know there are differences between two to three loads five five six loads there are differences between chief practice loads or import loads versus duty and hunting loads or even ex m193 and a lot of people say well you know ammo is ammo as long as it's loaded to spec it's the same well no it's not if you shoot some wolf 55 grain Steelcase pamela bang bang bang and then you load in some federal ex m193 there's a difference not only in felt recoil but noticeably in the percussion and the amount of energy between those two rounds that makes a difference additionally the chamber makes a difference how is the barrel cut you know here is the chamber of the barrel and when you're looking at that you know it's it it's not quite as easy to tell it is without the proper gauges and equipment but how this chamber is cut it does make a difference between a two to three cut a two to three wild a five five six or any of the hybrid cuts that chamber does make a difference in the cycling of the firearm as well and of course if you have a two to three chamber don't shoot five five six now you can get that reamed out a quality barrel will say on the barrel somewhere exactly what the chamber is now keep in mind there are you know different companies out there of different quality levels and I have seen companies that have their barrel safe five five six however when I've taken a gauge to it it's actually a two to three cut chamber and I've actually had to ream those out to get into cycle now this particular one this is a great barrel this is a rainier arms i'm not sure if you can see that on camera but then it has the brand info it has the chamber cut you know the rifling type etc so a good-quality barrel is going to have that information on the barrel don't rely on what's on the upper receiver now additionally one thing that makes a difference is the gas system which is the distance or length of the gas tube the distance between the port and the travel of the gas to the bolt carrier group that makes a difference as well as the gas port the gas port is this small hole right in the barrel right here that's what gas escapes out of travels through the block down the tube into the carrier so those things make a difference and the size of the gas port makes a difference to some companies purposely make really large gas ports because they want their gun to cycle in the cheapest of ammunition the downside is you have increased felt recoil cyclic rate issues you can have timing issues that the gun truly can be over gas that's actually getting too much gas and you have other companies that are you know using quality sight quality companies that are using smaller gas ports reasonably sized gas ports and it will tell you hey this may not function the cheapest of the ammunition depending on how you have it set up so a our basics is when you pull the trigger the gun goes bang we all we all get that but what actually you know goes on how the gun works how it cycles and everything like that under the hood may be new to some shooter so what happens is when we go bang we have that primer set off the powder that powder creates pressure it sends the bullet on the barrel after the bullet reaches about this point some of that gas some of that propellant that pressure starts to come up through the gas port and down the tube as the bullet continues we have all of that pressure building into the gas system this distance from when the bullet passes the gas port by the time it leaves is called a dwell time and that depends on the different gas system how much dwell time you have there is optimal dwell times for different length barrels of tetris will and again is that here just a second so as the gas pressure builds it goes down the tube goes into the carrier goes down into the bolt and cycles on you know unlocks it and then you also have the energy still once the bolt is unlocked and begins to it's unlocking phase and reroute travel of the carrier you also do have blowback as well so it's not a hundred percent a lot of people think that just this gas that's coming in the tube is moving the carrier to the rear and what the gas down the tube is really doing is its unlocking and starting the process but we still have that energy that also continues it as well so it's a system that works together but it is a locking system that's why with your carrier you'll notice when the bolt if you look at your just your carrier the bolt does cam back and forth into a locked and unlocked position similar to a bolt-action rifle I know it's not the same but it's similar to how a bolt-action rifle locks in so that's kind of the operation 101 there's more to it than that I'm able to do a separate video on that if you're really interested so far as gas systems go how did we get these different gas systems well traditionally we had a 20 inch barrel like as shown here and we had a rifle length gas system which is the longest traditional length gas system is this rifle length and what that basically means is it's a length that is an industry standard that was based on the 20 inch barrel when the 14 and 1/2 inch barrels came out that was a carbine they came out with what's called a carbine length and you can see the difference here so if we were to install this here you could see that it's a much shorter system and that goes with shorter barrels like this barrel right here is a thirteen point seven inch barrels for an idea I had for a project coming up to make an overall length of 16 with a fixed muzzle device that's pinned and welded to ATF specs but you can see here it kind of matches a similar dwell time to this longer barrel and then it kind of is proportional so when they had shorter barrels come out they had to shorten the gas system the pressure actually increases additionally there's mid-length which is kind of in between the two so we have a carbine length the rifle length and then we also have the mid length now the mid length is very popular with 16-inch guns it's very popular with some 14 and 1/2 inch guns depending on the manufacturer depending on the company that that does that but you can see it's kind of a in between if we were look at that on camera I'll get a close-up for you here and then of course the rifle lengths you can see the difference there in length now are these the only three no there's a shorter one called pistol and that's really popular in the 300 blackout or like the seven and a half inch AR builds they use a pistol length gas tube and then there are some intermediates and you know different hybrid gas systems that aren't as mainstream but there are some in betweens but the three main ones that you're going to see are carbine mid length and rifle now which one is the best well number one it's going to depend on your barrel if you're shooting a 16 inch barrel which is very common I prefer a mid length gas system because that still allows for a good amount of dwell time good felt recoil good pressures if I was shooting a 20 inch or maybe even an 18 I like the rifle length 14 and a half you could do a mid depending on the gas port size you can also do a carbine and then like on SVRs 10 and a half inch eleven and a half maybe even this 13 the carbine length is much more common so it kind of just scratching the surface there I know I've talked a lot but there's a lot of information under the hood of what's going on and what data is because I when I've worked on a lot of guns I've seen a lot of gas related issues and if you add a suppressor to that that can change the mix as well so let's talk about buffers for a second and the buffer is inside of the stock and it reciprocates with you know the bolt carrier travels to the rear there is a buffer and spring inside the receiver extension of your stock a lot of people call that the buffer tube it's really called the receiver extension now what the buffer does in combination with the spring so when the gun goes bang Wow bolt carrier cycles back it is stopped by the buffer and then it returns with the energy of the spring now why are there different buffers well we have the rifle buffer which is shown here the rifle buffer goes with traditionally the rifle gas systems and the rifle length receiver extension so these longer stocks have the longer buffer while when the carbine in the collapsible stock market started to you know be introduced they couldn't fit this in there so they needed something shorter so then they came out with the carbine buffer in a carbine spring to go with that shorter receiver extension now a common question I get from new a ar-15 owners is ok I have this buffer I took it apart and shake it and it's loose there's played something loose in it well that's actually how it's supposed to be it's almost kind of like a dead blow hammer in a way and if we were to take one apart this comes off as a roll pin that holds it together you actually have a combination of weights in here now this is a carbine these are all the same weight but we can also increase the weight by swapping this out for a tungsten weight which would be heavier and that would have a marketing traditionally on the face of h1 or h2 would have to h3 would have three and then there's also different you know heavier buffers in the market for different configurations pistol things like that which one do you use well some people say use the heaviest buffer you can that still cycles your gun you can but keep in mind if you get into adverse conditions or anything like that it could affect your cycling so the real reason why heavier buffers existed initially was the slow cyclic rate with machine guns and to prevent bolt bounce which is where the bolt carrier cycles it comes back but it actually bounces and then you don't get repetitive full auto fire in the semi-auto sporting community most people never know if their gun is bolt bouncing or not it's really a machine gun thing so we have heavier buffers for that however we can increase the feel of a gun with a slightly heavier buffer and increase reliability so on a 16 inch gun that's properly gassed a mid-length I'll usually run an h1 buffer maybe if I'm shooting suppressed I might run that a little bit differently to so it's again kind of just scratching the surface but this is just meant to be basic 101 gas system basic 101 buffer I hope that helped kind of answer your questions about gas basics buffer basics there's a lot to it if you have questions I would recommend seeking the assistance of a really competent gunsmith or armor especially if you're building you have more specific questions please ask we'll do more videos on this topic in the future as I realize that you might still have some questions but there's there's only so much we can pack into one short video and get started so I hope you found this helpful if you have the questions please leave comments in the section below we really do want to hear from you and if you have any ideas for future videos please let us know please like share and subscribe what really does mean a lot to us it really helps to channel grow and we look forward to seeing you in more future videos thank you very much for watching and have a great day

Channel: GUNS & TACTICS

Views: 400,589

Rating: 4.8916092 out of 5

Keywords: ar15, ar 15, ar15 gas, ar15 gas tube, ar15 gas block, ar gas, gunsandtactics, gunstactics, dave timm, davetimm, briefing room

Id: JSvT0cRzXL8

Length: 12min 31sec (751 seconds)

Published: Mon May 01 2017