D.I. vs. Piston Driven?!? What’s it all about?

The world of AR-15 pattered rifles is as crowded as the DMV on the last day of the month!  If you are in the market for a good rifle you have choices coming out of the wazoo!!!  One thing you should pay close attention to when shopping around is how the rifle operates.  As far as AR-15 patterned rifles go, you have two major choices:  D.I. (direct impingement) or Piston driven.  If you need a quick refresher on what exactly these two different actions are, PSA has you covered (as per usual!)!!

Eugene Stoner designed the first AR-15 rifles with Direct Impingement as the source of action.  In the simplest terms, D.I. systems have an open pathway (usually in the form of a hollowed out tube), that in essence recycles the gasses produced by discharged round.  The gas is sent from the point of release (normally the gas port), back to the receiver.  This flowing gas represents the action of the rifle, driving the entire system.  However, heat and the residue left by the gasses cause extreme fouling in the receiver.  Also, this system has no way to adjust the flow of gas.  As a result, using a can or using the rifle in extreme conditions may cause several malfunctions.

Piston driven systems seem to solve most of the issues presented by the more archaic D.I. designs.  Piston driven systems also use the gas to drive the action of the rifle, but as opposed to sending the gas back to the receiver, these systems use the gas to operate a piston.  In other words, the gasses never make it back to the receiver.  Another plus is that piston driven systems allow the user to control the flow of the gas to the piston.  This will accommodate cans and harsh conditions.

Take a look at some of the cool pics developed by PSA’s Creative Dept of a couple of our rifles!!  Our Ruger AR-556 is a D.I. rifle while the Sig Sauer 516 is a Piston driven rifle.  Both perform like well oiled machines and we can’t help but LOVE them!!!!

516 on log
Sig Sauer 516
Ruger AR-556 (accompanied by a Glock 19!)


***  If you are unfamiliar with firearms and/or their accessories, and want to learn more, PSA strongly suggests that you find, enroll, and attend a comprehensive and reputable firearms safety course. Firearms safety is all of OUR responsibility.  

We want to thank you for taking out the time to stop by our lane at the shooting range!!  We hope that you enjoyed your stay and hope that you stop back by early and often to catch up on all PSA updates!  We truly hope that we were able to hit the target, and if you ever have any questions please don’t hesitate to shoot them our way!!  We look forward to shooting the breeze with you soon again!!

And as always….remember to watch your six and stay low!!!

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