Tim Harmsen Of Military Arms Channel Begins An Interesting Run-To-Failure Test Of AR-15

BY Herschel Smith
2 months, 1 week ago

Like me, Tim is a champion and fan of the AR-15 design.  He begins an interesting test with a BCM rifle.

He shot 1000 rounds in 35 minutes.  We’ll see how far this goes before it gives up as he tracks this over time without cleaning or maintenance.

The guys at Wanat claimed that their Colts gave up after shooting 800 rounds in 30 minutes.  My bet is that they were firing in 3-round bursts.  Although I still can’t see how they managed to put more rounds downrange than Tim.

When Tim posted this a few minutes ago, I heard that Bob Scales puked in his cream of wheat.  His contract with H&K stipulates that no one can perform any more run-to-failure tests proving that no one really needs a piston system.

“Rifle is fine.”


  1. On April 12, 2019 at 10:04 am, BAP45 said:

    I really don’t understand Scales appeal. As far as I’ve seen the main reason for pistons was shorty barrels and suppressors. If the barrel is a normal length there’s really no need for them. But I’m no expert so if I’m wrong feel free to correct me.

  2. On April 12, 2019 at 10:06 am, sobiloff said:

    BCM typically sells with mid-length gas systems. (I didn’t see Tim specify in the video which length gas system this specific rifle has, so I’m assuming a bit here.) The Colt M-4 carbines in Wanat would have used carbine-length gas tubes, so what we’re probably seeing here is how over-gassed Colts will fail sooner than properly-gassed DI rifles.

  3. On April 12, 2019 at 10:17 am, MTHead said:

    Iv8888 got 830 rounds full auto before it spit one out the side of the barrel. Shooting semi, he’s going to have a hard time killing it. DI is lighter in the front and what the make AR platform the most accurate semi known to man.
    The only argument against AR’s is some general trying to get a “backdoor” retirement from H&K.

  4. On April 12, 2019 at 10:29 am, George said:

    I always thought the 20″ barrel and rifle length gas tube was the way to go. Just like Eugene Stoner intended.

    I bet the outcome of the early 2000’s testing results against the H&K, SCAR and some others would have been different if an A4 was used.

  5. On April 12, 2019 at 10:58 am, Bill said:

    A little speculation in regards to Wanat; the GIs there had no motivation to mis-report their weapons failures so I take them as accurate. Given the time and theater I am confident they were issued 62gn M885. The combination of a heavier bullet and a shorter gas system, and tighter rifling (1/7) will produce more heat. I think that is what killed those M4s. There’s a very good reason mid-length gas systems are more prevalent today. At Wanat we also know that for various reasons their belt-feds either weren’t there or were out of action, so those guys were trying to fill that gap with thier personal weapons …the M4s.

    Key point: the AR designs reliability has been demonstrated repeatedly. What happened at Wanat was NOT due to a design flaw. Rather, it was mismanagement by the DOD. The combination of site selection, OPSEC, logistic support, set the battle in motion. The combination of poor weapons upgrade management (gas system), and ammunition selection set up conditions for the weapons failures under the demand of battle.

    Now my personal prejudice: too many G-D Ring Knockers and Lawyers involved at all levels, and not enough NCOs.

  6. On April 12, 2019 at 11:08 am, MTHead said:

    Gas tube length makes little difference. as the amount of gas is regulated by the hole diameter. tube length only affects the “timing” of when the gasses start activating the bolt toward extraction. If the chamber is still pressurized, it over works the bolt lug/extraction system. which makes it prone to fouling.
    One of the ways you can tell is to look at the case head after extraction, if there’s a bright smudge. your timing is to advanced. that smudge is the extraction plunger being twisted against the case head while the case is still pressurized. its very noticeable on 308/ carbine length systems. thus the big move toward mid-length gas systems, even in starter barreled rifles and “pistols”.

  7. On April 12, 2019 at 12:20 pm, MTHead said:

    Shorter barrels.

  8. On April 12, 2019 at 1:56 pm, Pat Hines said:

    When I was gathering parts for my first AR-15 build, I examined every piston system available and solicited input from lots of folks. I also read many evaluations of piston systems, including the infamous bolt carrier tipping issue.

    I finally rejected going to a pistol system and built using the tried and trusted DI system. I have no regrets at all. My first AR build was one in 6.5 Grendel, no regrets there either, though I’ve build a number of ARs in standard 5.56NATO, too.

    In several slow-mo videos you can see the DI system blow dirt, sand, and debris out of the action, a sort of self cleaning feature. No, I do NOT want to see one more moron quip, “it shits where it eats”, either.

    I’d love to see a side by side firing to destruction of an AR-308, FAL, and a M1A. Expensive, yes, but well worth while. I don’t have a spare $6000.00 right now, or I’d do it.

  9. On April 12, 2019 at 2:01 pm, Pat Hines said:


    That’s one reason I don’t built AR-pistols with less than 10.5-11.5 barrel lengths. That first AR build I mentioned had a mid-length gas system. I talked to the man at Sabre Industries (before ATF put them out of business) and he explained the mid-length versus the carbine length gas set ups.

  10. On April 12, 2019 at 5:18 pm, MTHead said:

    I picked up a 8″ upper for next to nothing. Dropped a CMMG 22 LR conversion in it. it had A2 front sights, so I slapped an old carry handle sight I had laying around on it. What a hoot that thing is! Great for pest control, teaching the grand-kids. If I ever need full horsepower from it, 10 second bolt swap back to 556. That’s the thing about AR’s. Pure American versatility!

  11. On April 13, 2019 at 1:36 am, Jorge said:

    Wanat is like the Miami Shootout: multiple levels of awful decisions and idiocy are explained away by saying “our guns just weren’t good enough” so we can whitewash all the endemic leadership/management problems that caused the disaster (which people predicted for years beforehand) and pretend it’s just a technology problem, so we give more money to a defense contractor to make this new technology and everything will be fine.
    Grifters like Scales are a dime a dozen.

  12. On April 13, 2019 at 8:31 am, Ned said:

    I have had one failure with an AR. It was early on, when I had someone else work on one. The gas tube was bent and the key was striking it going into battery. Could have “fixed” it with a stick. That’s the only failure I can think of in various AR platforms.

  13. On April 13, 2019 at 10:33 am, John said:

    The Colt gun had the worst failure rate of all of tha M4 type rifles during the Army adoption
    trials several years ago and they chose it anyway. It’s a piece of junk.

  14. On April 13, 2019 at 10:41 am, John said:

    Look up the info. Here is just part: “The M4/M16 family is both praised and criticized for its current performance in the field. In recent years, the M4 finished dead last in a sandstorm reliability test, against 3 competitors that include a convertible M4 variant. Worse, the 4th place M4 had over 3.5x more jams than the 3rd place finisher. Was that a blip in M4 buys, or a breaking point? The Army moved forward with an “Individual Carbine” competition, but as the results started to show the M4 again lagging – even with ammunition changed to a round specially formulated to make the M4 shine – the Army abruptly stopped the process once again, stating that the performance superiority of the competing gun was not better to a degree making it worthwhile. The Army stated after the tests that only a result that was twice as good external link as the existing gun’s performance would signify an actionable performance difference.”

  15. On April 13, 2019 at 12:17 pm, DJ said:

    All good things must come to an end.

  16. On April 13, 2019 at 1:50 pm, =TW= said:

    Gas is contained in the barrel behind the projectile. Pressure bleeds into the gas tube when bullet passes the port, and drops significantly only after the bullet clears the muzzle.
    It seems that distance (volume) between gas port and muzzle is a variable that would affect timing.

  17. On April 13, 2019 at 7:01 pm, Gryphon said:

    “Run to Failure” with a lightweight Carbine is IMO somebody showing that they have More Money than Sense. OF COURSE a Lightweight, Air-Cooled Carbine isn’t going to Eat a Pallet of Ammo like a Water-Cooler Belt-Fed Machine Gun. Sure, in Desperate Combat Situations, Soldiers are going to Abuse their Weapons, until they are just a Handle for the Bayonet.

    Just Like Aircraft Design, Weapons Design is the Art of Engineering Management of Compromise to produce the Best Possible Product FOR A SPECIFIC PURPOSE. Would those Guys in Wanat have done Better with Browning BAR’s ? (given sufficient Ammo) Sure. Again, it always comes back to Mission Failure due to Piss-Poor Planning, and if anything, the Failures these poor Troops encountered were probably well Outside the Design Limits of the Weapons as Produced.

    If one Reads the Manual for most Closed-Bolt Firing Weapons, the Manufacturer will give a Warning about how many Rounds Fired Continuously will result in “Cook-Off” Rounds, and that probably represents a “Reasonable Limit” on that Weapon’s ability to handle Excessive Heating. Did these M4’s Fail before or after the number of Rounds that would produce Cook-Off?

    Those Guys may have been Lucky that their Guns held up to Abuse as well as they Did…

  18. On April 13, 2019 at 11:56 pm, MTHead said:

    TW, your right. from gas port to muzzle is called the “dwell” time. and it does push more gas into the system. But AR’s are engineered to vent excessive gas/pressure. so pressure spikes won’t damage the gun.(within perimeters of course).
    The standard answer to “over pressure” for a piston gun is to enlarge the port. make a massive operation rod,(so it won’t bend), with a strong spring to match. and let it bang. works great. but all that forward pressure on the barrel tweaks the accuracy out of the gun. That’s why Stoner designed the DI system. all the gas pressurizes is the bolt. nothing to bend. and once the bolt moves passed about a 1/2″ of power stroke. excessive gas gets vented.
    But, by the same token if any power is robbed , such as early extraction. the gun won’t cycle properly. and you stress the bolt lugs/extractor.

  19. On April 14, 2019 at 11:56 am, =TW= said:

    MTH- The piston systems on my M1 Carbine and my Mini 30 have worked fine for many years. (Aftermarket mods for the Mini are available. But that’s a whole ‘nother topic.)
    My AR was built before piston systems or “boutique” ammo were widely available. I chose 7.62X39 to share ammo with the Mini and my CZ527.
    Matched Aero Precision upper and lower, 16″ bbl, carbine length DI (port size as supplied), M4 BCG, A2 device. I tweaked the feed ramps slightly. M4 spring and buffer used, so I can mount a similar 5.56 upper if necessary.
    This carbine runs fine though I’m keeping an eye on the bolt.
    I don’t need a piston system, better to spend for a nice drop-in trigger instead. Or optics…

  20. On April 14, 2019 at 11:44 pm, MTHead said:

    TW, your rig should run for years. no problems. but that’s the wonderful part about AR’s. grab a new BCG an throw it in your kit. like I use to tell people who came in the shop with a problem. all mechanical systems break. with an AR I can generally fix it in 10 min. and fewer moving parts means less to break.
    A good trigger is so worth the cost. I’ve been using the POF-USA 4.5 lb. modular triggers for years. about $175.00. sometimes cheaper. but they come with a $35.00 KNS locking pin set. so it’s a good value. very crisp for an AR trigger.

RSS feed for comments on this post. TrackBack URL

Leave a comment

You are currently reading "Tim Harmsen Of Military Arms Channel Begins An Interesting Run-To-Failure Test Of AR-15", entry #20969 on The Captain's Journal.

This article is filed under the category(s) AR-15s,Firearms,Guns and was published April 12th, 2019 by Herschel Smith.

If you're interested in what else the The Captain's Journal has to say, you might try thumbing through the archives and visiting the main index, or; perhaps you would like to learn more about TCJ.

26th MEU (10)
Abu Muqawama (12)
ACOG (2)
ACOGs (1)
Afghan National Army (36)
Afghan National Police (17)
Afghanistan (679)
Afghanistan SOFA (4)
Agriculture in COIN (3)
AGW (1)
Air Force (34)
Air Power (9)
al Qaeda (83)
Ali al-Sistani (1)
America (16)
Ammunition (74)
Animals (32)
Ansar al Sunna (15)
Anthropology (3)
Antonin Scalia (1)
AR-15s (173)
Arghandab River Valley (1)
Arlington Cemetery (2)
Army (71)
Assassinations (2)
Assault Weapon Ban (27)
Australian Army (6)
Azerbaijan (4)
Backpacking (2)
Badr Organization (8)
Baitullah Mehsud (21)
Basra (17)
BATFE (77)
Battle of Bari Alai (2)
Battle of Wanat (18)
Battle Space Weight (3)
Bin Laden (7)
Blogroll (2)
Blogs (13)
Body Armor (18)
Books (3)
Border War (10)
Brady Campaign (1)
Britain (38)
British Army (35)
Camping (4)
Canada (2)
Castle Doctrine (1)
Caucasus (6)
Center For a New American Security (8)
Charity (3)
China (10)
Christmas (10)
CIA (27)
Civilian National Security Force (3)
Col. Gian Gentile (9)
Combat Outposts (3)
Combat Video (2)
Concerned Citizens (6)
Constabulary Actions (3)
Coolness Factor (2)
COP Keating (4)
Corruption in COIN (4)
Council on Foreign Relations (1)
Counterinsurgency (216)
DADT (2)
David Rohde (1)
Defense Contractors (2)
Department of Defense (143)
Department of Homeland Security (21)
Disaster Preparedness (3)
Distributed Operations (5)
Dogs (12)
Donald Trump (8)
Drone Campaign (3)
EFV (3)
Egypt (12)
El Salvador (1)
Embassy Security (1)
Enemy Spotters (1)
Expeditionary Warfare (17)
F-22 (2)
F-35 (1)
Fallujah (17)
Far East (3)
Fathers and Sons (2)
Favorite (1)
Fazlullah (3)
FBI (27)
Featured (180)
Federal Firearms Laws (18)
Financing the Taliban (2)
Firearms (989)
Football (1)
Force Projection (35)
Force Protection (4)
Force Transformation (1)
Foreign Policy (27)
Fukushima Reactor Accident (6)
Ganjgal (1)
Garmsir (1)
general (15)
General Amos (1)
General James Mattis (1)
General McChrystal (43)
General McKiernan (6)
General Rodriguez (3)
General Suleimani (7)
Georgia (19)
Google (1)
Gulbuddin Hekmatyar (1)
Gun Control (979)
Guns (1,490)
Guns In National Parks (3)
Haditha Roundup (10)
Haiti (2)
Haqqani Network (9)
Hate Mail (8)
Hekmatyar (1)
Heroism (4)
Hezbollah (12)
High Capacity Magazines (13)
High Value Targets (9)
Homecoming (1)
Homeland Security (1)
Horses (1)
Humor (19)
ICOS (1)
IEDs (7)
Immigration (81)
India (10)
Infantry (4)
Information Warfare (2)
Infrastructure (2)
Intelligence (23)
Intelligence Bulletin (6)
Iran (169)
Iraq (379)
Iraq SOFA (23)
Islamic Facism (61)
Islamists (91)
Israel (18)
Jaish al Mahdi (21)
Jalalabad (1)
Japan (2)
Jihadists (80)
John Nagl (5)
Joint Intelligence Centers (1)
JRTN (1)
Kabul (1)
Kajaki Dam (1)
Kamdesh (9)
Kandahar (12)
Karachi (7)
Kashmir (2)
Khost Province (1)
Khyber (11)
Knife Blogging (3)
Korea (4)
Korengal Valley (3)
Kunar Province (20)
Kurdistan (3)
Language in COIN (5)
Language in Statecraft (1)
Language Interpreters (2)
Lashkar-e-Taiba (2)
Law Enforcement (3)
Lawfare (7)
Leadership (5)
Lebanon (6)
Leon Panetta (2)
Let Them Fight (2)
Libya (14)
Lines of Effort (3)
Littoral Combat (8)
Logistics (50)
Long Guns (1)
Lt. Col. Allen West (2)
Marine Corps (258)
Marines in Bakwa (1)
Marines in Helmand (67)
Marjah (4)
Media (42)
Memorial Day (5)
Mexican Cartels (32)
Mexico (44)
Michael Yon (5)
Micromanaging the Military (7)
Middle East (1)
Military Blogging (26)
Military Contractors (4)
Military Equipment (24)
Militia (5)
Mitt Romney (3)
Monetary Policy (1)
Moqtada al Sadr (2)
Mosul (4)
Mountains (24)
MRAPs (1)
Mullah Baradar (1)
Mullah Fazlullah (1)
Mullah Omar (3)
Musa Qala (4)
Music (16)
Muslim Brotherhood (6)
Nation Building (2)
National Internet IDs (1)
National Rifle Association (52)
NATO (15)
Navy (22)
Navy Corpsman (1)
NCOs (3)
News (1)
NGOs (2)
Nicholas Schmidle (2)
Now Zad (19)
NSA (3)
NSA James L. Jones (6)
Nuclear (57)
Nuristan (8)
Obama Administration (218)
Offshore Balancing (1)
Operation Alljah (7)
Operation Khanjar (14)
Ossetia (7)
Pakistan (165)
Paktya Province (1)
Palestine (5)
Patriotism (6)
Patrolling (1)
Pech River Valley (11)
Personal (58)
Petraeus (14)
Pictures (1)
Piracy (13)
Pistol (2)
Pizzagate (21)
Police (397)
Police in COIN (3)
Policy (15)
Politics (434)
Poppy (2)
PPEs (1)
Prisons in Counterinsurgency (12)
Project Gunrunner (20)
PRTs (1)
Qatar (1)
Quadrennial Defense Review (2)
Quds Force (13)
Quetta Shura (1)
RAND (3)
Recommended Reading (14)
Refueling Tanker (1)
Religion (157)
Religion and Insurgency (19)
Reuters (1)
Rick Perry (4)
Rifles (1)
Roads (4)
Rolling Stone (1)
Ron Paul (1)
ROTC (1)
Rules of Engagement (75)
Rumsfeld (1)
Russia (29)
Sabbatical (1)
Sangin (1)
Saqlawiyah (1)
Satellite Patrols (2)
Saudi Arabia (4)
Scenes from Iraq (1)
Second Amendment (253)
Second Amendment Quick Hits (2)
Secretary Gates (9)
Sharia Law (3)
Shura Ittehad-ul-Mujahiden (1)
SIIC (2)
Sirajuddin Haqqani (1)
Small Wars (72)
Snipers (9)
Sniveling Lackeys (2)
Soft Power (4)
Somalia (8)
Sons of Afghanistan (1)
Sons of Iraq (2)
Special Forces (28)
Squad Rushes (1)
State Department (20)
Statistics (1)
Sunni Insurgency (10)
Support to Infantry Ratio (1)
Supreme Court (3)
Survival (25)
SWAT Raids (54)
Syria (38)
Tactical Drills (1)
Tactical Gear (4)
Taliban (167)
Taliban Massing of Forces (4)
Tarmiyah (1)
TBI (1)
Technology (17)
Tehrik-i-Taliban (78)
Terrain in Combat (1)
Terrorism (94)
Thanksgiving (8)
The Anbar Narrative (23)
The Art of War (5)
The Fallen (1)
The Long War (20)
The Surge (3)
The Wounded (13)
Thomas Barnett (1)
Transnational Insurgencies (5)
Tribes (5)
TSA (18)
TSA Ineptitude (11)
TTPs (1)
U.S. Border Patrol (5)
U.S. Border Security (14)
U.S. Sovereignty (17)
UAVs (2)
UBL (4)
Ukraine (3)
Uncategorized (55)
Universal Background Check (3)
Unrestricted Warfare (4)
USS Iwo Jima (2)
USS San Antonio (1)
Uzbekistan (1)
V-22 Osprey (4)
Veterans (2)
Vietnam (1)
War & Warfare (218)
War & Warfare (40)
War Movies (3)
War Reporting (19)
Wardak Province (1)
Warriors (6)
Waziristan (1)
Weapons and Tactics (60)
West Point (1)
Winter Operations (1)
Women in Combat (21)
WTF? (1)
Yemen (1)

June 2019
May 2019
April 2019
March 2019
February 2019
January 2019
December 2018
November 2018
October 2018
September 2018
August 2018
July 2018
June 2018
May 2018
April 2018
March 2018
February 2018
January 2018
December 2017
November 2017
October 2017
September 2017
August 2017
July 2017
June 2017
May 2017
April 2017
March 2017
February 2017
January 2017
December 2016
November 2016
October 2016
September 2016
August 2016
July 2016
June 2016
May 2016
April 2016
March 2016
February 2016
January 2016
December 2015
November 2015
October 2015
September 2015
August 2015
July 2015
June 2015
May 2015
April 2015
March 2015
February 2015
January 2015
December 2014
November 2014
October 2014
September 2014
August 2014
July 2014
June 2014
May 2014
April 2014
March 2014
February 2014
January 2014
December 2013
November 2013
October 2013
September 2013
August 2013
July 2013
June 2013
May 2013
April 2013
March 2013
February 2013
January 2013
December 2012
November 2012
October 2012
September 2012
August 2012
July 2012
June 2012
May 2012
April 2012
March 2012
February 2012
January 2012
December 2011
November 2011
October 2011
September 2011
August 2011
July 2011
June 2011
May 2011
April 2011
March 2011
February 2011
January 2011
December 2010
November 2010
October 2010
September 2010
August 2010
July 2010
June 2010
May 2010
April 2010
March 2010
February 2010
January 2010
December 2009
November 2009
October 2009
September 2009
August 2009
July 2009
June 2009
May 2009
April 2009
March 2009
February 2009
January 2009
December 2008
November 2008
October 2008
September 2008
August 2008
July 2008
June 2008
May 2008
April 2008
March 2008
February 2008
January 2008
December 2007
November 2007
October 2007
September 2007
August 2007
July 2007
June 2007
May 2007
April 2007
March 2007
February 2007
January 2007
December 2006
November 2006
October 2006
September 2006
August 2006
July 2006
June 2006
May 2006

about · archives · contact · register

Copyright © 2006-2019 Captain's Journal. All rights reserved.