Tactical Tailor

Testing The 4.6mm Round With SMGLee

During the filming of one of the Larry Vicker’s Tac-TV show in California, he left with me a few boxes of the L-Tech 4.6 rounds as souvenir. It really just sat on top of my safe collecting dust until recently my friend in firearm division of a local Metro PD mentioned to me that a certain division within the PD is looking into the MP7 platform as a support weapon to gap the pistol and the carbine, but he was worried about the stopping power of the 4.6 round. Lo and behold, I remember the L-Tech ammo sitting on top of my safe and told him about it.

The L-Tech 31gr 4.6 loaded with Barnes TSX a solid copper projectile is the heaviest 4.6 round available on the commercial market and the performance of the TSX in the Blackhill 5.56 brown tip is just simply phenomenal, the 5.56 TSX is also a cartridge being considered as their SWAT carbine. He started to do some research on L-Tech ammo all the while H&K also introduced L-Tech to the division looking to adapt the MP7 as a choice for the duty round. The firearms division conducted some serious testing and the rest is history.

Which bring us to this video. We had the pleasure to work with H&K along with the help of the metro PD that adopted the MP7, and the L-Tech 4.6 TSX round on this test just to see if the MP7 with the proper ammunition can as effective on target as some of the more popular cartridges the market as to offer. As of this time, the Metro PD have adapted this platform and they are now running the L-Tech 31gr 4.6mm round as their duty round (the same round we tested in this video).

Besides testing the L-Tech 4.6, we also ran it against some of the more popular rounds on the market in order to give you a look into the performance potential of the L-Tech 31gr TSX 4.6 round and the H&K MP7.

Testing notes

For each caliber, two batches of 10 rounds each were pulled from the same ammunition lot.

For one of the batches of ten, the bullets were pulled from the casings and weighed to obtain the highest, lowest, and average weight as well as standard deviation to check for weight consistency of the ammunition lot.

The second batch of ten rounds were fired through the chronograph to obtain the highest, lowest, average, and standard deviation of muzzle velocity of this ammunition lot.

We were unable to secure a proper gun rest for the gelatin testing. Instead, all weapons were measured for their heights from the ground and leveled as carefully as possible.

We fully conformed to the instructions for mixture and cooling of the test gelatin. Gelatin temperature was carefully controlled during its manufacture, storage, and transportation and the gelatin was measured again for proper temperature just before commencing our tests.

A pump action air rifle was used to test the gelatin for consistency. The air rifle was tested at 587ft/sec muzzle velocity and the BB projectile was able to penetrate the gelatin at approximately 3.3″. This test helped to determine that the gelatin block was of the correct consistency and temperature range for proper ballistic testing.

Disclaimer: This test was performed to give the viewer a general idea of the performance of the 4.6mm round against other established calibers and is for information purposes only. Do not base your requirements and adoption of the caliber based solely on this video.

This post was written by SMGLee – www.facebook.com/tacticalsmglee


23 Responses to “Testing The 4.6mm Round With SMGLee”

  1. bloke_from_ohio says:

    I don’t know much about the MP7. But I was under the impression the 4.6 was origianlly designed to defeat body armor by going really fast. Would that cause an over penetration risk in a LE type scenario? Most departments I know of use soft tip ammo partially to mitigate that risk. Or at least that is part of the justification for not using ball like the military.

    • straps says:

      Police officers who are issued this ammunition train to put their rounds into things capable of stopping them (an armored adversary with a good backstop). This means taking ONLY that shot that will achieve a positive outcome.

      Police are criminally and civilly liable for every bullet they launch, and this is no more true anywhere on the planet than California.

      If you have ANY doubts about the need for a “mere city cop” to have this technology, here’s some context:


      Armored adversaries (many affiliated with cartels from south of the border) pop up regularly in smaller ops.

      Worth noting that LAPD is more of a regional multidisciplinary law enforcement agency than a city PD, anyway.

      • Jerry says:

        As a general rule, LE doesn’t have to fight bad guys in body armor. Heck after spending so much time in Afghanistan and Iraq I can’t even count anymore‚ĶI never got in fight with bad guys wearing armor ether.

        The 4.6mm PDWs, are glorified 22 magnums. A solution looking for a problem. The came out of the NATO trials in the 80’s when it was discovered Soviet troops were issued body armor. NATO wanted a “in-between”weapon, larger than a pistol and smaller than a assault rifle for support troops. The USSR falls, so does the need for the weapon system.

        But FN and H&K had sunk a ton of cash into developing the weapons. Had to sell them somewhere, hence marketed for PSD, LE, SpecOps and “geardos”.

        Why not just go with a 5.56mm with green-tip? Its more versatile platform, in general use and cheaper than 4.6mm. You have a wide variety of ammunition choices. Plus you don’t have to buy new weapons from FN or H&K.

        • sean s says:

          The M855 is about as shitty as a round there is for 5.56. So many better options out there. And the MP7 is a excellent weapon, it’s why the SMUs use them.

          • LM says:

            The MP7 is unneeded.

            There is nothing 4.6 or 5.7 will do that 5.56 cant do better.

            • AB says:

              And there’s nothing a 5.56 will do that a .50 BMG can’t do better. But I don’t think humping a Ma Deuce is an option.

              Different rounds for different purposes. And the 5.7 and 4.6 fill a niche role due to the size of the platforms that shoot them. Something a 5.56 platform has a hard time doing.

      • Horror says:

        “Armored adversaries (many affiliated with cartels from south of the border) pop up regularly in smaller ops.”

        Do you have a source for this? Genuinely curious. Violent bank takeovers like the north hollywood one are exceedingly rare. I don’t think one bank robbery that occured 17 years ago is a good enough reason

        • straps says:

          LE doesn’t deal with adversaries in body armor:


          He would have made a mess if he got to his destination at a very dense (24/7 foot and vehicle traffic) urban location…

          Or if this POS decided to keep shooting, as opposed to giving up because he shot his wad after killing 8..


          Cartel discussion:




          Other accounts aren’t examined carefully in open source outlets before being spun to conform to agendas. When equipment and TTP [especially people using both effectively] is discovered more effort is made at intelligence than public information. People with a first-hand professional interest in Cartel behavior and reach have anecdotes also.

          Dismissing 4.6 as a glorified .22 or why bother when he have 5.56 (especially ignoring the engineering of the VERY modern platforms designed around them–as opposed to the Stoner design-a great rifle & carbine that makes for a middling SBR), well, I got nothing. As said, it’s a tool to fill a gap. With the right training it does that well–as Level IV protection becomes lighter and more discreet.

        • SMGLee says:

          If you live in the area, you will see some pretty serious crime that the main stream media avoid reporting.

          6 months ago, sewage system had to clear out the main processing facility when they found a badly maimed Hispanic female body with full on tats inside the pipes. part of the body was found in the City of Industry facility and other parts were found in an Orange co facility…..body can’t be identified, no suspects were found..the body was assumed dumped into the sewage sysem from up streams…..

          year and half ago, a trash can was dumped on the side of Carbon Canyon road. the fully sealed trash can contained a body of hispanics male.. no identification and no suspect.

          I can keep on going, and the media keep on avoiding these crimes associated witht he cartels….cartel makles regualr hits in the US… its a fact, and it is a problem

  2. SMGLee says:

    If you look at the video closely, the L-Tech 4.6 round penetrated 16″ with expansion to .38″ and with velocity to 2300fps. view the video from 3:00 to about 3:18. you can stop the video to read the data more closely.

  3. Major Mike says:

    The irony of filming TV shows about firearms banned in California in California using the firearms entertainment permit dodge is pretty strange.

    Guys, I know California is all kewl and the chicks are hot (or the guys, these days), but the firearms community has to stop using and abetting the special deal a chosen few Hollywood outfits have with Sacramento.

    Film in AZ or Texas. Someplace where the average vet can go out and buy an AR-15 or own an SBR or a suppressor or whatever kewl toy you’re showing off.

    Because the day ‘they’ decide to turn on you, they’ll make you out to be a combination of Dohrner and Lakis, with some Lanza mixed in.

    • Tetsuo says:

      What the heck does this have to do with the 4.6mm round and its ballistics???

      • straps says:

        Points to the fact that someone’s STILL mad about (a) FOPA, and/or (b) the decision of a manufacturer NOTORIOUSLY dismissive of Citizen shooters not to sell a semi-auto variant of a nicely recoil-managed platform with some admirable ballistics; (c) far as what’s available in Cali, we’re fighting the good fight here. We fought back after the last round of media hysteria/political grandstanding, won a judgement AGAINST our notorious CCW laws and we continue to mount campaigns against fake moral superiority and those who shroud themselves in it (NFA one day).

  4. JoshZ says:

    I really don’t think the 4.6 has any place in LE. The 9mm easily out preformed it.

  5. Alex says:

    Motor units in a local city near me use MP7’s. They keep em locked away in their side cases.

    Still not sure why they have them when there are solutions for putting AR-15’s on bikes.

  6. SMGLee says:

    Those that doubt the MP7 against 5.56 carbine…can just stop now.

    No 5.56 carbine can compare to the H&K MP7 in the diminutive package and stopping power with ammunition such as LTech 31gr TSX

    • JoshZ says:

      Did you just say 4.6 LTech is more lethal then any 5.56 round? Because it looks like that’s what you just said. Just making sure that’s all.

      • mark says:

        I think he means that it outperforms 5.56 in terms of weapons size. It obviously does not outperform a 16″-20″ rifle barrel 556.

        So, the MP7 is 16.5″ folded with a 7″ barrel, 25″ stock extended. Given that most 5.56 rounds depend on velocity to achieve fragmentation (2600fps I recall?) it would be very interesting to stack the MP7 up against a 7″ barreled AR15.

  7. mark says:

    Thanks for the test. I’d like to see a head to head with the MP7 against the P90 with Elite’s S4M load (28gr aluminum JHP @2600fps out of the Five-Seven.)

    The B&T MP9 chambered in 6.5CBJ would also make for an amazing test. If you haven’t checked out the 6.5CBJ, it’s awesome. Saboted Tungsten rounds that outperform AP 5.56 and 7.62.

  8. Bill says:

    The 4.6 and 5.7 have already been tested extensively by NATO and through real world opperations and the verdict is in, they both suck. The 5.7 sucks less but sucks just the same. I see nothing here that proves otherwise.

    Then there’s the weapon. Let’s take into account that the barrel is mounted to a polymer frame and you’ll see zero shift if you shoot it a lot. The G36 and the UMP both have this problem, I see no reason why the MP7 would be different. I’ve shot the G36 and UMP and was not impressed with the accuracy. The G3 and MP5 were good guns that built HK but these recent offerings are horrible and HK knows it.

  9. Davan says:

    Don’t know why we are listing to someone who has gotten an entire SEAL command shitcaned and sells the firearms industry’s secrets to main land china.