Gas or Piston ? ? ?

Discussion in 'AR-15 Discussion' started by STF, Mar 18, 2010.

  1. STF

    STF New Member

    So I am new to the whole gun thing and am looking to buy either a M4 or an AR-15 and I am wondering if I should go with the direct gas injected or the gas-piston? I've been reading a little on both but I'm still a little lost. I've found some Bushmaster's for around 1K but those are the gas ones, however, I was looking at the Bushmaster BCWA3F16M4-GP (gas piston) and it is about 1500. Is the gas piston worth the extra 500?

    I guess I should also note that I am not really planning on shooting thousands of rounds through the weapon as I am in college and on a budget. Any help would be great !
  2. Tackleberry1

    Tackleberry1 New Member

    First understand the difference between the original direct gas impingement design and the new gas piston guns so you can make the best decision for yourself.

    1. Gas Pistons are not new, in fact, they predate direct gas impingement by about 30 years. Most all semi auto and selective fire rifles designed for military use used the gas piston beginning in the late 30's and most still do.

    2. Direct gas impingement as designed by Eugene Stoner for the AR rifles, which also became the US Military's M-16 rifles were built with the express goal of reducing recoil in order to achieve CONTROLLABLE automatic fire. Stoner achieved this with a couple of design modifications that were unique to the AR 15 at that time but the primary advance was eliminating the HEAVY RECIPROCATION GAS PISTON and instead allowing the gas to vent directly back into the receiver to unlock the bolt and send it to the rear extracting the spent casing and then striping a fresh round from the magazine into the chamber as it's propelled back into battery by the buffer spring. The effect was DRAMATIC. I've fired full auto M-16s, M-4's, AK's, and M14's and none of the piston guns hold a candle to gas impingement if the measuring stick is CONTROLLABLE AUTOMATIC FIRE.

    With all that said, I suspect that like most of us civilians you won't be buying a full auto M4 but rather one of the semi auto only M4 variants and if your looking at Bushmasters you cant go wrong as long as you stay away from the CARBON upper receiver guns. I've heard the carbon uppers have had problems.

    IMO the only big advantage to going GAS PISTON is the time you'll save cleaning the gun. Tradition gas guns, as I said, vent hot gases back into the receiver and cause tremendous fouling within the chamber, bolt, and bolt carrier. I've never had a gas gun fail to function as long as it was clean when I began shooting but they MUST be cleaned well after each firing and doing it right will take 1 hr minimum if you know what your doing.

    If you go GAS Piston you can cut the cleaning time down to about 15 minutes. You will have increased recoil but this is hardly a problem given the 5.56mm/.223 Rem cartridges. They just don't kick much, especially in a buffered semi auto.

    Personally, I'd go with a gas flat top and use the extra $500 to buy a nice EO TECH holographic projection site but then again I enjoy cleaning my guns because it keeps me in the garage away from a house full of noisy kids.


    It all comes downs to where you crap!
    Last edited: Mar 18, 2010

  3. yesicarry

    yesicarry New Member

    I've got a Bushy Piston.. Bolt stays a lot more cleaner ! 300 rounds through it and the only part of the bolt that was dirty was the extractor. Not one FTE or FTF in 500 rounds fired.. I personally prefer the piston design. But, more parts to pay attention to. Have to really pay attention to wear and tear in the upper carrier and proper lube.. But then again, it's nothing for me to spend 2 hours cleaning every nook and cranny and love every minute.
  4. Murfdeezy

    Murfdeezy New Member

    If you buy an AR new, it will only take you an hour to clean it at first. Once you learn the takedown of the rifle, the cleaning isn't so bad. If you clean it after every range day, it should take less time than that, once you are familiar with it anyway. If you get lazy and start waiting for every few times at the range, you will be scrubbing for sure, and might have some jams. Ultimately, it depends on how well you clean it and how often you clean it. The more you take it down and clean it, the faster you get. A little CLP goes a long way too. Lube it and treat it nice, and it will love you back. Just my opinion. I love them. I have fired plenty during my military career. I can't speak to the cleanliness of the gas piston rifles, but $500 could get you another decent gun. It just comes down to whether you are willing to do the work after the range. Are you willing to take the time to clean your truck after you go mudding? If so, you won't have a problem. Save a few buck and get 2 guns. That will make the extra time cleaning it seem much more worth while. haha. Good luck.
  5. TXnorton

    TXnorton New Member

    You question was "Is the gas piston worth the extra 500?"

    My answer is no.

    IMHO, the AR gas piston concept is a solution in search of a problem.

    Having owned and extensively fired an old Colt SP1 AR-15 since 1980, I just laugh at people who make statements that the AR gas system is "dirty" and the gas piston system is cleaner. That statement in and of itself may be factually true, but to what extent will this make ANY difference in your use of the AR?

    I shot my SP-1 for 20 years before I was ever told that the gas tubes are a problem and had to be cleaned regularly. Now I clean my gas tube once a year whether it needs it or not.

    I always clean and lubricate any firearm after shooting. I do disassemble the bolt group for cleaning then lubricating every time. Let me see, that must take an extra 5 minutes in the overall cleaning/lubricating process. If I had a gas piston AR, I would feel like I needed to clean the gas piston each time.

    I have nothing against the gas piston AR variants. Hell, I have an AK, M1 Garand, and a new M1A. Gas piston or op rod designs are great. But your question was is it worth another $500. Again, NO.
  6. mag318

    mag318 Member

    Is the piston system just a marketing ploy or a truly useful upgrade? After pondering this for awhile I started to look at PS ARs. Finally after curiosity got the better of me I bought a Smith & Wesson M&P15ps. I've been shooting ARs since the early 60s and have owned several. After my first trip to the range with my new M&P I came away impressed. Cleaning the M&P after the range was much easier as the bolt was not carboned up at all, even the piston only required a wipe down with some Hoppes.
    I've read that the Army has asked for a round of new M4 testing and one of their specifications was the inclusion of a piston system. There has to be a good reason for this. I also read that the SEALS that did in the Somali pirates used piston system HK416s, so they do have experience with the PS. Even Colt is coming out with a PS gun which speaks volumes. Maintenance is important with an AR and the DI examples have to be well lubed, the PS examples run well on very little lubrication and I think this is a big consideration. It will be interesting if future M4 contracts go to one employing a piston.

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    Last edited: Mar 26, 2010
  7. Darth AkSarBen

    Darth AkSarBen Member

    I run an Adams Arms piston on my Rock River Arms 6.8 SPC II upper. I wouldn't have it any other way. The gas that has dirt has carbon. If you ever look at the wear potential of what carbon can do, you would want a piston. You would also get a great understanding on how important the oil filter is on your car and why it is important to remove suspendable carbon from your oil.

    Talking with Adams Arms and in some emails I understand that Smith & Wesson and Daniel Defense are also 2 OEM distributors that are going to put the Adams Arms Piston system on their production rifles and offer as a piston alternative choice.

    The bolt and carrier not only stay cleaner, but cooler. Heat and carbon build up is minimized with the piston system. Since Adams ARms free floats their piston arangement, it does not affect the harmonics of the barrel when shooting.

    Here is my 6.8 SPC II with the AA system on it. Never shot one bullet though it with DI.

  8. ARnoob

    ARnoob New Member

    Gas piston is the way to go (for me).

    • Easy maintenance
    • Less time spent cleaning
    • Fewer stoppages
    • More reliable
    • Just plain cool

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  9. JonM

    JonM Moderator

    for your first AR i would skip over the gas piston system gun. i have a ruger sr556 a colt sp1 dpms panther M4 and a RRA 458 socom.

    other than the dirty vs clean factor there is a substantial weight increase for going gas piston. gas piston conversions and gas piston ARs havent been around terribly long and some still seem to be going through teething issues. maybe another few years and all the big makers will have all the errors shaken out.

    i like my ruger SR but it was pricey compaired to a similar DGI AR. i like it a lot but price being an issue for you then skip gas piston.
  10. Darth AkSarBen

    Darth AkSarBen Member

    I wouldn't consder a few ounce, at most, a substantial increase. The Adams Arms replaces the original gas block/front sight with their own gas block. It might weight an ounce more...maybe. The gas tube is replaced by a piston rod, which might be another ounce. The carrier is different but then it's probably only an ounce difference at most.

    My Rock River Arms is a shooter and weighs about the same with the Adams ARms system as it did when I got it with the DI gas system. I wouldn't go back. I have a DI .223 that I plan to get the AA for in the very near future.