Adams Arms Gas Piston/Op-Rod Retrofit Kits for Tactical and Competition AR (AR-15)/M4/M4A1 Carbines/SBRs: Smooth-Shooting, Accurate, and Reliable (Photos and Video!)

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By Jeff Gurwitch

October 28 2010
Updated on 10/29/10

I was first introduced to the Adams Arms gas piston/op-rod (operating rod) system by fellow soldier Kirk Broyles while we were both competing at the 2009 Blue Ridge 3-Gun Championship. Kirk, shooting for Adams Arms, showed me his system and said he would set me up with Jim Granger of Adams Arms.

That was in April. By June, Jim had set me up with two Adams Arms piston uppers: one a 7.5-inch (7.5″) length Pistol (PDW) Distributor Piston System, and the other a 14.5-inch (14.5″)-barreled Mid Length Distributor Piston upper.

Shooting impressions:

So, at the time I received the uppers, I was of the mindset that yes, piston guns run cleaner, but, beyond that, they just weren’t as smooth shooting as a tradition DI (Direct Impingement) gun. Well, shooting the Adams Arms system has changed my opinion.

I’ve found that the Adams Arms piston system shoots just as smooth as a DI system. Using the 14.5 Mid-Length Distributor Piston System AR upper, the felt recoil was even less than the AR-15 carbine (M4 style with carbine length gas system) I used for comparison. The combination of mid-length piston system (which are known have less felt recoil, anyway) and Adams Arms’ method of bleeding out excess gas made the weapon’s recoil impulse impressively smooth. Compared to other piston guns I’ve used (LWRC and HK416), Adams Arms is by far the smoothest system in terms of felt recoil. Additionally, the system is also one of the easiest to take apart. The whole piston system comes out the front of the gas block with one press of a detent button and a half turn counter-clockwise.

The Adams Arms 7.5″ Pistol (PDW) Distributor Piston System AR upper’s shooting qualities also impressed me. Having only a 7.5 inch barrel, I’d expected it to be an obnoxiously-loud fire-breathing dragon! However, to my surprise, the recoil and muzzle blast felt no more than a traditional 10″ SBR (Short Barrel Rifle) DI gun. Again, with the Adams Arms piston system, all the excess gas is being vented out the front.

Over the next 9 months, I put a about 9,000 rounds through the Adams Arms 14.5″ mid-length piston upper, and about 2000-3000 rounds through the 7.5″ PDW piston upper. The majority of the ammo I used was 55-grain 5.56x45mm (5.56mm)/.223 Rem. I liked the Adams Arms 14.5″ mid-length piston upper so much it’s become the primary set up I use for 3-Gun competition. I’v only had one issue with the 14.5 upper; the firing pin went bad at about 6,000-round mark (nothing to do with the piston system). As far as carrier tilt or any other signs of abnormal wear, I haven’t noticed anything out of the norm. The 14.5 upper has just over 10,000 rounds through it, and you you’d never know it’s a piston rifle by looking at the buffer tube, as there’s no abnormal wear. Inside the upper receiver there are no abnormal marks from any sort of cam pin drag. During the first 5 months of use, I cleaned the 14.5″ upper one time at about the 6,000-round mark, before the 2009 Ft Benning 3-Gun Challenge.

Last March, I hit Jim Granger up for another Adams Arms upper to try out. This time a 10.5″ upper. During a 6-week period, I ran about 3,000rds through it without any cleaning. When I first got it, I lubed up the carrier with a little CLP, and that was it. I specifically told Jim Granger that “I’m never going to clean it, and I’m going to shoot it until it breaks!” It is now September (2010), and, at least another 1,000rds later, I have yet to take it down all the way and clean it. I have run a bore snake down the barrel a few times, but I have not taken the bolt out of the carrier to clean It.

It’s now been a little over a year since getting those first Adams Arms uppers. I now have well over 15,000 rounds through my three uppers, collectively, and they’re all still going strong!

Editor’s Note: In the top (first) photo, you can see an Arredondo AR Magwell (flared magwell), of which technical/tactical shooting instructor John Romaszka of Romaszka Tactical Training (RTT) is also a fan (and user), attached to the weapon, and what would appear to be a Lancer Systems L5 translucent polymer magazine being utilized. In the second photo and video, you can see the author, Jeff Gurwitch, wearing ITW FASTMAG (also written FAST-MAG) mag carriers (magazine carriers) loaded with Lancer Systems L5 5.56mm AR mags. DefenseReview (DR) likes and uses both of these products, as well.

Photo(s) Credit: Jeff Gurwitch

About the Author (Jeff Gurwitch):
– Has been a competitive shooter for the last 10 years: USPSA, IDPA, and 3-Gun.
– U.S. Army 3rd Special Forces Group, Ft. Bragg, NC.
– Spent 3 years as an instructor at the John F. Kennedy Special Warfare Center and School
– Spent 8 years with U.S. Army 5th Special Forces Group, Ft. Campbell KY and did 3 tours in Iraq.
– Graduated the U.S. Army Special Forces Qualification course in 1998 as a Weapons Sergeant.
– Spent 7 years in the mechanized infantry and Airborne.
– Served in First Gulf War (Operation Desert Storm) in Iraq with the 1st Armored Division.
– Joined the U.S. Army in June of 1990 as an infantryman.

Company Contact Info:

Adams Arms
612 Florida Ave.
Palm Harbor, FL 34683
Toll Free: 877-461-2572
Local: 727-853-0550
Fax: 727-853-0551
Email Sales: [email protected]
Email Jim Granger: [email protected]

© Copyright 2010 and Jeff Gurwitch. All rights reserved. This content/material may not be republished, broadcast, rewritten or redistributed without first receiving permission and providing proper credit and appropriate links.

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Adams Arms Gas Piston/Op-Rod Retrofit Kits for Tactical and Competition AR (AR-15)/M4/M4A1 Carbines/SBRs: Smooth-Shooting, Accurate, and Reliable (Photos and Video!) by

About David Crane

David Crane started publishing online in 2001. Since that time, governments, military organizations, Special Operators (i.e. professional trigger pullers), agencies, and civilian tactical shooters the world over have come to depend on Defense Review as the authoritative source of news and information on "the latest and greatest" in the field of military defense and tactical technology and hardware, including tactical firearms, ammunition, equipment, gear, and training.

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