Lightning Review: Sintercore Tripwire Ambi Charging Handle

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Somehow I have been drafted as “The Charging Handle” guy here at TFB. At first, I was suspect of the role, but have grown to enjoy it immensely. I have been witness to innovation on one of the most benign and often neglected AR parts. Also, I have been witness to some… interesting ideas. How did this one fare? The Sintercore Tripwire is in the innovation category; it will just need solid execution during manufacture.

A selection of handles used during testing. From right to left: BeatenZone ATCH, Sintercore Tripwire, Armageddon Tactical GMS-15, BCM Gunfighter Mod 3

A selection of handles used during testing. From right to left: BeatenZone ATCH, Sintercore Tripwire, Armageddon Tactical GMS-15, BCM Gunfighter Mod 3

So what sets this model apart in a market replete with plethora of options? Basically, the Sintercore Tripwire is an actual charging “handle.” It has no latch what-so-ever, just a spring-loaded arm that takes advantages of the cut-outs on the upper receiver. As Sintercore calls it, the “trip” is shaped like a latch, but rounded on the front and rear contact surfaces. It is held in place by friction on the receiver cut-out only provided by a strong stainless spring.

The Tripwire over a Armageddon Tactical GMS-15. It is easy to see the trip on the left side. The handles extended about the same distance and do not go past the forward assist.

The Tripwire over a Armageddon Tactical GMS-15. It is easy to see the trip on the left side. The handles extended about the same distance and do not go past the forward assist.

Features (Courtesy of Sintercore):

  • Automatic locking and unlocking with a simple, hands-off latching system
  • Instant, one finger bolt manipulation from either side of the AR-15, without the need to actuate a separate lever
  • The latch is rounded and automatically “trips” (rolls off the upper receiver) when either side of the handle is pulled back
  • For the AR-15 and all compatible firearms
  • Width: about 2.5″ and does not extend beyond the forward assist
  • Weight: about 1 oz
  • Material: Bar stock 7075-T6 with type 3 class 2 hardcoat anodizing
  • Patent pending

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Thoughts on the Sintercore Tripwire:

Sintercore sent TFB a prototype Tripwire for evaluation. It arrived timely from Sintercore in a non-descript padded USPS envelope. Even with the prototype status, the handle was in good form. No machining marks or flaws in the finish were visible and it inserted easily into my Del-Ton upper for initial testing. It likewise worked in a Adam’s Arms and Bushmaster upper receiver. The Tripwire did not work in a Houlding Precision upper which was also available for testing. I notified Sintercore and they promise this will not be an issue in production handles.

Looks good!

Looks good!

Eager to see if the concept was sound, I immediately started testing the trip mechanism in the upper. The Tripwire slides in and out of battery easily. With the bolt locked to the rear and handle with it, the handle has no issues going into battery when the bolt is released. Racking it without a bolt inserted was likewise easy with no hang-ups on the receiver.

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The handle is designed to be low profile. The “wings” as I will call it are very thin compared to a other handles with further machining to reduce weight (which is near a single ounce). The front and back manipulation surfaces have vertical striations to ease manipulation. I tested the handle on a hot day, and not once did my handle slip on my fingers laterally, but the vertical cuts didn’t quite hold perfectly. My sweating fingers could move a bit, but they never did come off the latch during manipulation.

You can see the vertical only cuts on the handle.

You can see the vertical only cuts on the handle.

Shooting with the handle was just like any other… and that is a good thing. Without the flat rear surface, my concern was the Tripwire would jar from battery. Not the case. Using a DI receiver with mid-length gas and Federal XM193, the handle did not move a bit, even during rapid fire.

Quite simply, it worked.

The Good:

  • Works as advertised
  • The trip never came loose under rapid fire
  • No issues going into battery every time
  • Wicked cool aesthetics

The Notable:

  • First-run pricing is going for only $50 on their website. (Note, this is for pre-orders).
  • If this is machined, why not add a hood like the Armageddon Tactical latch for suppressed shooters?
  • Needs horizontal cuts or checkering to complete the package.

The Bad:

  • Fit in MIL-SPEC uppers without issue, but did not fit into a Houlding Precision upper receiver. The tabs were just a bit too long. (The manufacturer says this will be addressed in production handles).

Final Thoughts:

I am honestly disappointed I had to send it back. It worked well in my MIL-spec AR’s and is fully ambidextrous for only $50. Solid two thumbs up on the Tripwire.

Note to the readers from Phil:

I spoke with the owner about the glitch Nathan S had. As it turns out the problem was the difference between a forged and billet upper. The owner/designer contacted me to let me know the problem was a simple fix and the needed change was made for the production units. It’s since been tested on billet uppers with no problems.

Gallery:



Nathan S.

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

Nathan can be reached at Nathan.S@TheFirearmBlog.com

The above post is my opinion and does not reflect the views of any company or organization.


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  • Vhyrus

    Sounds like a winner, especially at that price.

  • ColaBox

    I still don’t see the problem with the standard charging handle.

    • sianmink

      It’s not very good for support-hand operation.

    • I’ve had to many standard charging handles fail. The pin breaks or I bend the body—it’s always something with those.

  • Rusty Shackleford

    I prefer the Rainer Arms Raptor for its robust roll pins linkage system as well as its ability to act as a gas blocker for suppressor use, but I might be tempted to try this out.

    • Waldorf

      I agree. Nothing is better than the Rainier Raptor.

      • Dracon1201

        Unless you want something light. This is also far simpler. The gas blocking system is also cool, but on an Adams Arms AR, it’s redundant. This makes more sense in that regard.

  • An Interested Person

    So. Many. Charging handles.

    I honestly don`t know how you pick which one to put on your rifles.

    • I haven’t been able to try this one yet but I’d like to at some point. I imagine I’ll really like it. I’m using the Armageddon right now.

  • Nicks87

    Would like to see one that fits DPMS gen 2 308 rifles. Or even a raptor that fits the gen 2s would be nice as well.

  • Adam aka eddie d.

    I really like this design!
    The wings have a slight forward curvature/cant not as radical as the Gunfighter’s,
    still having a bit more bend than the Raptor’s – just the right amount.
    Looks to be a light, useful part with a well thought-out, understated design, nothing tacticool or fancy-schmancy.

    My only issue is with the “trip”/latch: you mention it’s a stainless piece – I guess heat treated to ca. spring hardness (46-50 hRc) because of its role/working principle.
    Though similar hardness hardcoat anodizing on both the handle and the receiver can delay that for quite a while, but won’t the steel latch wear the receiver out over time?
    Would be nice to see the test gun(s) Sintercore has been using for the evaluations,
    it should give us some info on long term effect on the receiver.
    My guess is even if there’s any abrasion wear, it will be negligible, but it never hurts to know for sure.

    A small hood would also be a nice idea, but IMO it’s not a show stopper.
    Don’t know how this sleek, lightweight design could incorporate it.

    • Neal – Sintercore

      The trip-latch is 7075-T6 hardcoat anodized, not stainless. The spring providing biasing force is stainless, however (perhaps that’s what you read?). The trip-latch and receiver, being similarly hardcoat anodized, provide a nearly wear-free solution. Based on my testing, you should expect the same amount of abrasion wear as you’d see using a charging handle with a normal latch: this is, very little.

      Thanks to Nathan S. for the review.

      • Adam aka eddie d.

        Oh, I see, thanks a lot for the correction Neal!
        Quality information from the manufacturer.
        I misread that part in the review.

        Also, good to see a company that is actively following the discussion on its product!

      • Cymond

        The Sintercore website currently shows something different:

        Material: [Handle: Bar stock 7075-T6 with type 3 class 2 hardcoat anodizing]; [Trip-latch: 3D printed carbon filled polymer]

        • Secundius

          @ Cymond.

          You might consider GRAPHENE plastic, which has a 150,000,000psi rating. or an impact force of ~20,000-G’s, or something like a object traveling at 0.003c (899,377.374m/s to 0.0m/s, sudden deceleration.

          • Cymond

            I don’t see what you’re trying to tell me, what the point is.

            I was just trying to point out the difference (contradiction?) between the Sintercore webpage and what “Neal – Sintercore” was saying. Maybe they’ve changed the design since Neal posted here?

            “The trip-latch is 7075-T6 hardcoat anodized”
            “Trip-latch: 3D printed carbon filled polymer”

            So which is it? 7075-T6 aluminum or carbon filled polymer?

          • Secundius

            @ Cymond.

            What temperatures ranges, are you looking at?

          • Neal-Sintercore

            Hi,
            We did change the material to carbon filled polymer after this review posted. Sorry for the confusion. Our testing showed zero wear to the receiver and zero wear to the trip-latch itself using the carbon polymer, while the hardcoat anodized aluminum always produced some slight wear to both surfaces (as I mentioned in my earlier post).

            There are no drawbacks with the material change, and the price didn’t rise, either. It’s a win-win. Wish I would have had the carbon filled polymer trip-latch ready for the TFB review, but the testing was still in process.

            Feel free to e-mail or call with any questions. My contact info is available at http://www.sintercore.com

            Thanks for ordering a Tripwire, Cymond.

            Neal

          • Cymond

            Neal, thanks for the info!

            I’m excited about the Tripwire because I had a similar idea a few days before TFB posted about the Tripwire. I had an aftermarket latch in a milspec charging handle, and the steel latch had a very sharp catch. I rounded the sharp edge off with a file, and started wondering about a completely rounded catch that would simply glide off the receiver without needing to be manually opened. Basically more of a detent than a latch. I intuitively like the idea of a pivoting detent better than the steel-ball detent like on the SLR Rifleworks charging handle, but I can’t explain why. http://www.ar15news.com/2013/12/16/sneak-peek-slr-rifleworks-latchless-ambi-charging-handle/ And I just discovered the Butthead charging handle a few minutes ago (Butthead? seriously?) http://www.thetacticaltoolbox.com/AR15-Bolts-Charging-Handles.html

            Anyway, I think the Tripwire seems like a great idea to me, and possibly the best of a new generation of latchless charging handles. I’m going to put the Tripwire in my “main” carbine and move my BCM into my secondary carbine.

          • Cymond

            Again, I’m not sure what you’re getting at. I honestly don’t know how warm a charging handle gets. I haven’t gone shooting since I got out of California, so I’ve never had a chance to run my AR-15 very hard. Regardless, it probably won’t be much above ambient temperatures.

            Still, what is your point? You’re talking about technical specs of materials, I was pointing out an inconsistency in the information posted here (which Neal has already explained).

        • Cymond

          Update: I got an email that says the anodizing company is behind schedule. The website now says “IN POST-PRODUCTION; estimated ship time: week of Nov.2, 2014” which is 2 weeks later than originally expected.

          This is not a value statement or judgment, just a statement of facts.

  • Ken

    I second the need for checkering, maybe the manufacturer can add it as an option or do some more testing to see which way works best.

  • Secundius

    I hunt near Barrow, Alaska in winter where temperatures typically run a -60 degress Fahrenheit, on a “warm” day. I have a Alexander Arms .50Beowulf (12.7x42mm) livery. In winter this brutal, charging handles have a nasty habit of breaking of at the worst times. I’d like to have a charging handle similar to the BeatenZone ATCH. Preferably “ambidextrous” so they an be used with heavy gloves. In either Ti6AI4V Titanium Alloy, 440/420 Stainless Steel or E01 Tool Steel. Any suggestions, anyone.???

  • Formynder

    Just a correction on the first photo caption, it says right to left but actually names them from left to right.