Rangemasters/ Armorers Piston Operated AR's Question

[7anthony7]

Hello,

We are currently looking at replacing some of our Colt AR's and are looking at going to a piston operated system and wanted to see if any other departments are using them and if there has been any problems? Also, have you seen a noticable diffrence in them, or are they basically the same? I would imagine the cleaning would be a bit better. Any parts breaking down? I've read up on some reviews and we are planning on getting a tester, but wanted to see if anyone has been using them and what the outcome has been.

Thank you for any info!

Anthony

[paladin4415]

At this time San Diego PD has decided not to authorize any of the piston guns. The general feeling being that none of the piston guns have a long proven record of reliability like properly built DI guns do. A properly maintained and lubed DI gun will run for thousands of rounds, and very rarely are Police shootings thousands of rounds.

[tyrist]

We got the HK416 but it's not in wide issue.

[SoCalDep]

I know LASD SEB (SED and K9) have been testing/using the HK416.

[Jonathan Doe]

I heard from the reliable source that US forces that used K&K 416's returned many of their rifles to the H&K for problems they wouldn't tell me. I do not really care for the gas piston AR systems. Gas pistol rifles tend to kick a little more sharply, in my experience.

[Tallship]

The original reason for gas pistons was to lessen the carbon buidlup in the bolt after lengthy firing sessions. Good idea for the military when you might be firing a couple hundred rounds fighting off insurgents. Unnecessary for the patrol rifle in MOST places. We just had an OIS where the two deps fired two rounds each from their patrol rifles, and the bad guy with the shotgun was spared the hassle of a trial.

[SoCalDep]

Hey topgun7...Do you know if the HK416 has the carrier modifications (as compared to the DI system) to prevent carrier tilt? I know that some current piston uppers have them (Stag 8 comes to mind) and I'm wondering if the 416, being one of the earlier of the new wave piston uppers didn't and that caused the problem.

[seabass]

I have shot DI guns for many years.

I switched over to a LWRC piston upper when they were first released.

Overall, piston guns are easier and faster to clean. The real benefits of piston over DI guns is if you shot a lot of rounds over a long period of time.

[Jonathan Doe]

Hey topgun7...Do you know if the HK416 has the carrier modifications (as compared to the DI system) to prevent carrier tilt? I know that some current piston uppers have them (Stag 8 comes to mind) and I'm wondering if the 416, being one of the earlier of the new wave piston uppers didn't and that caused the problem.

My friend who gave me the info is out of town on an assignment. He will be back by July. If I can get a hold of him before then, I will ask him.

[Average Joe American]

I am not a fan of the DI system but in the grand scheme of things, cops will most often NOT be in a sustained fire fight. Sustained meaning, an AR that starts off in a gun fight clean and oiled gets so built up with carbon that it malfunctions.

The North Hollywood shootout was probably the longest gun battle ever recorded in law enforcement history and even then it probably wasnt enough to cause a carbon build up malfunction.

City streets arent dusty like Afghanistan, and even the reports from the sandbox of the M4 malfunctioning under dusty conditions are rare.

Cops dont need to jump on the piston band wagon unless their dept. happens to have spare cash? No need for them in my opinion.

Speeding up cleaning time doesnt seem like enough justification to waste more tax payers money?

[BigDogatPlay]

The North Hollywood shootout was probably the longest gun battle ever recorded in law enforcement history and even then it probably wasnt enough to cause a carbon build up malfunction.

There also weren't any patrol rifles deployed in that incident. All the first responders were fighting with handguns and shotguns for most of the action.

The SLA shootout in 1974, in which something like 9000 rounds were fired between the good guys and the bad guys, is likely a much better benchmark. There were two teams of LAPD SWAT on point and directly engaged that would have had ARs deployed. I am not aware of any LEO weapon malfunctions in that engagement.

The bad guys were armed with:

Four M-1 .30-caliber carbines. All had been "converted" capable of being fired only as fully automatic weapons.
A Browning semiautomatic rifle (Sports Model), .30-06 caliber.
A Remington semiautomatic rifle, .244 caliber.
Seven sawed-off 12-gauge shotguns (manufacturers included Mossberg, Ithaca, and Winchester).
Two Mauser HSc double-action automatic pistols, .380.
A Colt .45 automatic pistol (the military model).
Two .38-caliber revolvers; one a Smith & Wesson snub-nosed Chief's Special, the other a blue-steeled Rossi with a three-inch barrel

[7anthony7]

Thank you for the info. I appreciate it.

[Cyc Wid It]

Just curious... I saw on TV that LAPD SWAT uses the LWRC PSD in 6.8mm. Any chance that caliber becomes more popular among LEOs?

[Josh3239]

Anthony,

I do remember a PD in Arizona placed an order for some HK416s and every single one of them suffered serious malfunctions. HK replaced them no questions asked and the replacements worked perfect. HK never told them what happend to those 416s, I still think it is interesting how well that was swept under the rug.

I have heard of issues with several big name piston ARs but most cases seem to be user errors. The XCRs haven't been doing to well in the EAG courses and EAG also reports that Sig556 users typically aren't as effective as the guys running ARs. EAG has also reported that one of their T&E LWRC rifles seems to have a couple of problems after a couple thousand rounds. At a Magpul Dynamics course an Osprey completely sheared off a gas key. Then of course there seems to be a problem with carrier tilt in the Rugers.