Results 1 to 6 of 6

Thread: Gas Piston AR Build Question

  1. #1
    Member
    Join Date
    Nov 2006
    Location
    Anchorage, Alaska, United States
    Posts
    302

    Default Gas Piston AR Build Question

    Hey all, I'm building and AR-15 and was wondering if anyone on here has any experience with the gas pistion systems that are all the rage.

    My thinking was that I would put one on this build from the word go. I am looking to see if anyone has purchased an M4 or AR15 equipped with one of these gas piston systems or purchased the system to retrofit or build another rifle.

    Do you have experience with a company from whom I can buy just the piston system without buying one of their rifles.

    LWRC is making some nice rifles that have the system but I'm unsure if they sell just the system. This site shows pretty well how these things work. http://www.lwrifles.com/tech.php

    Bushmaster seems to have a system available, linked here, it seems good but it's alot of money to spend without somebody having some personal experience with it. http://www.bushmaster.com/

    These people say only their armorer can install their system, so it doesn't do me much good since I'm hoping to do it myself.
    http://primaryweapons.com/store/pc/v...p?idCategory=7

    Anyway, any experience will be helpfull, thanks.

  2. #2
    Member Big Al's Avatar
    Join Date
    Jun 2007
    Location
    Palmer,Alaska
    Posts
    1,737

    Default

    Quote Originally Posted by AKF View Post
    Hey all, I'm building and AR-15 and was wondering if anyone on here has any experience with the gas pistion systems that are all the rage.

    My thinking was that I would put one on this build from the word go. I am looking to see if anyone has purchased an M4 or AR15 equipped with one of these gas piston systems or purchased the system to retrofit or build another rifle.

    Do you have experience with a company from whom I can buy just the piston system without buying one of their rifles.

    LWRC is making some nice rifles that have the system but I'm unsure if they sell just the system. This site shows pretty well how these things work. http://www.lwrifles.com/tech.php

    Bushmaster seems to have a system available, linked here, it seems good but it's alot of money to spend without somebody having some personal experience with it. http://www.bushmaster.com/

    These people say only their armorer can install their system, so it doesn't do me much good since I'm hoping to do it myself.
    http://primaryweapons.com/store/pc/v...p?idCategory=7

    Anyway, any experience will be helpfull, thanks.
    This is just the opinion of an old guy. I have never seen a reason for or the need of a gas piston system on the AR. It's a solution looking for a problem. Gas pistons systems are vary much less reliable than the gas tube system of the AR. I remember all the fun with the M-60, the M-14 and the Garand cleaning the gas system. I also remember the gas pistons getting stuck. Welcome to the world of the single shot rifle.
    "The tree of liberty must be refreshed from time to time with the blood of patriots and tryants." (Thomas Jefferson

  3. #3
    Member
    Join Date
    Nov 2006
    Location
    Anchorage, Alaska, United States
    Posts
    302

    Default

    Thanks, you always give a good perspective. I think I will save myself 500 bucks and go with the regular gas system. Thanks again.

  4. #4
    Member
    Join Date
    Sep 2007
    Location
    Fredericksburg, Virginia
    Posts
    10

    Default Direct impingement versus gas piston

    Virtually all the systems being currently looked at seriously by the US military have gas pistons. What constitutes a more desirable method of operation for a civilian rifle and a military battle rifle and the opportunities available to maintain it as required for reliable operation are quite different. Given quality construction and assembly either system can deliver good service and both are mature technologies well understood by firearms designers. If you don't mind the operating system blowing combustion products back into the action then stay with the direct impingement system and save the money you would spend on a piston modification.

  5. #5
    Member Big Al's Avatar
    Join Date
    Jun 2007
    Location
    Palmer,Alaska
    Posts
    1,737

    Default

    Quote Originally Posted by CrustyJohn View Post
    Virtually all the systems being currently looked at seriously by the US military have gas pistons. What constitutes a more desirable method of operation for a civilian rifle and a military battle rifle and the opportunities available to maintain it as required for reliable operation are quite different. Given quality construction and assembly either system can deliver good service and both are mature technologies well understood by firearms designers. If you don't mind the operating system blowing combustion products back into the action then stay with the direct impingement system and save the money you would spend on a piston modification.
    You think that the gas piston/operating rod does not blow gas back into the action? Have you looked or noticed the scarf cut on an M-60 operating rod? What do you think the scarf cuts are all about? I don't know of any operating gas blow back system that does not put some gas back into the action, including the long recoil system as the BROWNING reciprocating barrel. The only system that operates without gas in the system is mechanically driven non-gas operated, such as the chain drive/gear driven. As an example is the M-134, M-5 and thirty or more mechanically driven systems.

    I have never known either system to offer any advantage in keeping the system any cleaner in operation, except to say that I have seen a great number of failure to feed, failure to return to battery with gas piston operating rod systems. The M-14/M-1 were always prone to these failures. That they required more maintenance is a fact that is proven throughout their service life. Delayed blow back or any system that uses gas to unlock the bolt is going to have gas in the action, short stroke piston still had gas in the action even though the operating guide rod had a gas block.. Remember that there is no reason to vent the barrel than to move the gas in a rearward direction except to function feed the action.

    Such is the nature of high speed gas operated actions.
    "The tree of liberty must be refreshed from time to time with the blood of patriots and tryants." (Thomas Jefferson

  6. #6
    Member
    Join Date
    Sep 2007
    Location
    Fredericksburg, Virginia
    Posts
    10

    Default

    Quote Originally Posted by Big Al View Post
    You think that the gas piston/operating rod does not blow gas back into the action? Have you looked or noticed the scarf cut on an M-60 operating rod? What do you think the scarf cuts are all about? I don't know of any operating gas blow back system that does not put some gas back into the action, including the long recoil system as the BROWNING reciprocating barrel. The only system that operates without gas in the system is mechanically driven non-gas operated, such as the chain drive/gear driven. As an example is the M-134, M-5 and thirty or more mechanically driven systems.

    I have never known either system to offer any advantage in keeping the system any cleaner in operation, except to say that I have seen a great number of failure to feed, failure to return to battery with gas piston operating rod systems. The M-14/M-1 were always prone to these failures. That they required more maintenance is a fact that is proven throughout their service life. Delayed blow back or any system that uses gas to unlock the bolt is going to have gas in the action, short stroke piston still had gas in the action even though the operating guide rod had a gas block.. Remember that there is no reason to vent the barrel than to move the gas in a rearward direction except to function feed the action.

    Such is the nature of high speed gas operated actions.
    Big Al,
    I’m not sure what you mean by the term “high speed gas operated actions”, but yes I do think that a gas piston operating system does not deliberately blow gas tapped from the bore straight back into the action. At the same time any operating system that opens the bolt promptly before the cartridge case, chamber and barrel have blown down to atmospheric pressure are going to introduce some gas and combustion products into the action. The direct impingement systems derived from the Lungman have a somewhat greater problem in this respect and are sensitive to the types of propellant used. In witness to this phenomenon one has merely to look at the profusion of specific carbon removing solvents and products that have been introduced in the last couple of decades. As to the issue of the inherent advantages of the two systems I would point out as mature designs of each system the M4-M16 family versus the Kalashnikov system. I think that the reliability and need for frequent and detailed maintenance of the two systems speak for themselves. I think that it is significant that the current crop of rifles competing for production contracts are piston operated when the bidders fully realize that the weapons will be subjected to extensive testing with particular emphasis on reliability and the occurrence of both stoppages and failures.
    B/T/W the Browning design with the moving barrel is a recoil operated design, not gas operated. Incidentally the externally powered chain guns and Gatling designs are prone to very substantial buildup of combustion products in and around the action/breech mechanisms. I stand by my previous statement that either system can deliver good service.
    Last edited by CrustyJohn; 09-04-2008 at 09:30. Reason: good grammar and technical correctness

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •