Ballistic Radio’s 20K Round Test of A Knight’s AR-15

Ballistic Radio has been running their Knight’s SR-15 pretty hard. How hard? They’ve so far fired 9,500 rounds, without any cleaning or weapon-induced malfunctions. The picture at the title of this article says a lot, but there’s a video as well.

Realistically, there are very few weapons as reliable as a well-made, well-maintained AR-15. Ballistic Radio’s goal is to reach 20,000 rounds. Best of luck to them!

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • USMC03Vet

    You’re making me blush.
    – Kalashnikov

  • Joshua

    Will be interesting to see how it looks at 20,000 rounds. Most bolts will go 10,000 on a standard AR, but once you get past 12,000-14,000 they break so this should be interesting.

    • vereceleritas

      SR-15’s are not standard AR’s though. They have an improved bolt design that was specifically intended to prolong service life, so I actually expect it to last 20K rounds.

      • Joshua

        That’s my point. I want to see how it fares after the point where a standard M4 will fail.

        On our M4A1’s once your bolt was past 10,000 rounds it could let go at any moment, so I look forward to seeing how it performs after this point.

        • Ah, gotcha now.

          • Joshua

            Right now their rifle is in the range of what a M4A1 that has been run hard will handle, give it another 5,000 rounds and it’s to the point where we really see how the changes affect the life of the parts beyond what the current standard is capable of.

          • shootintexan

            Regarding the longevity of cut rifled barrels, back in the mid 80s, I was fortunate to have Bill Wylde put together a Service rifle with Obermeyer barrel. I asked Bill what barrel life I could expect and his reply was ‘I don’t know. I have seen rifles with 10,000 rounds still shooting well.’ Given that this was with the rather sedate rate of fire of NRA matches but that is still a lot of rounds (IMO!). Likely rate of fire is more important than total rounds.

          • Hank Seiter

            Operative word “sedate”. Barrel life is always extended through timed firing. Rapid firing (particularly full-auto fire) will really erode barrels/rifling bad. But then you already knew that because I know I’m preaching to the choir here.
            Mechanically, one could probably chart number of rounds against rapidity of fire and come up with an interesting graph for each caliber that would also be dependent on metal composition of barrel and methods employed to cut rifling (vs. hammer-forged).
            I occasionally shoot a Weatherby .257 Magnum and at 3500 fps that 115 grain and 66 grains of IMR 4350 is going to yield a useful barrel life somewhere under 3000 rounds. Right now it’s shooting 1.25 to 1.5 MOA about a 1000 rounds into its life. Even with a perfect muzzle crown, throat erosion as a result of so much powder burning in a magnum case is the biggest issue. Rifling wear by the bullet would be very secondary.

          • shootintexan

            Sedate LOL! That is a good description
            Yes, that would be a most interesting graph! And VERY expensive to develop. Amazed that you expect to get that many rounds out of the .257 Wby. I’d have thought 1500 would be about it. Always wanted one as I am a big fan of .25s., ie, Roberts and -06.

    • As V said, this has the fancy-dancy stronger Knight’s bolt.

    • ColaBox

      Only 10k? I thought bcg lasted a lot longer, only the gas rings that need replacing around that time.

    • One of my BCGs has about 16,000 rounds and just keeps on ticking.

  • Evan

    They did have one failure to eject. said it was due to a soft case rim.

    • Do you feel that qualifies as “weapon-induced”?

      • Joshua

        Depends, did the extractor rip off a part of the case rim? If so then probably ammunition related, if the extractor slipped off the case rim then its rifle related.

        • They seemed to think it was the ammo’s fault. I don’t know, wasn’t there.

  • JumpIf NotZero

    Impossible! I read on the Internet that DI guns need to be cleaned every 10 rounds!

    • Didja get that one from iowaclass?

      • JumpIf NotZero

        He doesn’t know…. but HE KNOWS.

    • Knights Armament: directly impinging on what you read on gun forums across the web.

    • LOL–yea right:-)

    • Patrick Mingle

      Ohhhhh so anti-gunners are just trying to help AR owners out by reminding them to clean after every mag.

      • mosinman

        it’s not a magazine it’s a 30 caliber clip! that your evil AR-15 can empty in half a second. *(it becomes a quarter of a second if you add the vile Shoulder Thing That Goes Up Device)

    • n0truscotsman

      I’ve argued this since the late 80s and everybody thought I was mentally insane. Im glad the nails are finally being driven into this coffin, as they should have been since the M16A1 came out.

  • Christian Hedegaard-Schou

    As long as you keep the gas rings properly lubed, an AR will run itself into the ground without any major issues.

  • Kivaari

    That is impressive performance. I have always liked the AR15/M16 pattern rifles. I love how this one rifle has taken such abuse and kept on running. Simply amazing.

  • Long Stroke Piston

    Shit where you eat :^)

    • 1911a145acp

      Or have TOO much gas……..

  • Kivaari

    I wonder how the rifling is doing. A hammer forged barrel will outlast cut or button rifled barrels. I would expect MOST barrels to not do well after 5,000 rounds. The HK G3s will last for a much longer round count. Conventional (old fashioned) bores simply are not as good as hammer forged and work-hardened bores. In handguns I have fired close to 30,000 out of a Glock M17. In the issue MP5s we reached close to 50,000. At 35,000 the roller locking plate would fail. The newer spring device outlasts the plate. None of the guns, Glocks or HK MP5s had good bores. But 9mm is less of a challenge than 5.56mm.
    This rifle is amazing.

    • According to Andrew’s testing, if they’re firing American ammunition, they should get at least 13K out of the barrel before it just quits. Russian stuff is way harder on the bore.

      • Kivaari

        Was that with a hammer forged barrel? I’ve never seen a high power rifle get that far with conventional rifling. I have seen many hunting rifles and varmint rifles in particular with bores worn out with under 1.000 rounds. The throat being scoured by hot gases.

        • They were Bushmaster MOE series, so I’m sure they were CHF. I have a Colt AR with over 6K round of Russian ammo, and it still shoots straight.

          • Joshua

            Yes I contacted Bushmaster after that test and they verified all their rifles come with a CHF barrel.

          • Kivaari

            That’s good news as well. My HBAR shoots very well. I just need to add a higher quality scope and mount. That usually means I have to spend another $1100 to start.

          • Kivaari

            That is pretty good. I have started three new test pieces, with a Colt M4, Bushmaster HBAR and a Bravo Company mid-length. I will never have enough money to test them in the extreme.

          • Joshua

            I can tell you in testing with M855A1 that a M4 barrel will be shot out by 6,000 rounds. Now this was done in as little as a month, but accuracy went from 1.5moa to 5.5moa at the 6,200 round mark. By 7,000 rounds we were looking at 6moa.

          • I wonder that the mechanical wear was that great. Regardless, the additional wear doesn’t really seem to be a problem.

          • Kivaari

            It isn’t the bullet mechanically crossing the rifling it is the hot gasses. Running 100 grains of 4831 down a bore is a real scrubbing.

          • Kivaari

            That is what I have seen over 50 years of being around guns. Getting 5000 is good. Try some of the over-bore rifles like the .264 Win. A few hundred can eat a throat out.

      • Taylor TX

        Great link, thanks for sharing it. I shoot a lot of steel cased ammo but have somehow not come across a test I found thorough enough until this one.

    • Cornelius Carroll

      Glock barrel are melonited. Can’t speak to MP5s. With a CL’d CHF barrel in 5.56 throat erosion is generally an issue before rifling. I wish someone would make and test a CHF barrel that’s been melonited :/ alas, it doesn’t seem anyone wants to shell out for the mandrel.

    • Joshua

      You can’t compare bores that see nothing but 9mm to bores that see nothing but 5.56×45. The wear characteristics are far different and no CHF barrel will last 35,000-50,000 with 5.56.

      The most even manuf. quote is 20,000 and that is generally a far cry from what they really are capable of.

      • Kivaari

        That’s why I put the last sentence on this comment. I know that pistol caliber barrels last a long time. Other than frame and throat erosion on magnum revolvers.

      • Kivaari

        Don’t believe HK when they say they have a two week turn around onMP5s. More like 6 months when you need a barrel. Ours was loaned out to another agency and they managed to “ring” the barrel. At least on the AR, we could do the change in-house.

    • mosinman

      isn’t it claimed that hexagonal rifling lasts longer?

      • Kivaari

        Polygonal, like HK and Glock is CHF, and has a work hardened surface, that resists wear much longer. I remember years ago seeing an HK ad for the military G3 with polygonal CHF bores running to 70,000. I knew they were better, but not that much better. It was a company ad, so maybe they could back it up. It was said at the time that it took 2 minutes to form the barrel blank into a finished barrel. Maybe the bore dropping through a two story high machine can do it.

  • I blame our ammunition shortages on things like this. 😛 (humor)

    Even at $0.25/rd, this test is going to be hella expensive.

  • I don’t think I could do one of these tests. At some point (probably around 2k rounds) I would beak down and be compelled to clean the thing.

    • TFB Reader

      I know. It’s impressive, but I should have waited until after dinner to look at those pictures.

    • Hank Seiter

      Like you, I once put 1K through one of my ARs and felt compelled to clean it. I did notice the tail end of the bolt behind the gas ring, which gets a real beating from the hot gases piped-in from the barrel vent hole, was exhibiting some pitting. It was probably from the heavy moisture that was accumulating from the heating-and-cooling cycles creating some mild form of acid from the gas exhaust and carbon build-up. This happened in late fall and early winter about 20 years ago. I eventually replaced the bolt and kept the original bolt for back-up or spare parts.

      Ran like a champ and didn’t have a single malfunction. I was lubricating where possible during my “torture test”.

  • lol

    it also costs 1000 dollars more than any other rifle on the market. thats why it works so well.

    thats the kinda cash you need to lay down if you want a reliable gas impingement system.

    • My $1100 Colt would like to have a word with you.

    • 1911a145acp

      You are confusing reliability and durability- not the same thing.

    • Joshua

      $1,000 more than any rifle on the market? You can get a SR-15 for around $2,000.

    • Grindstone50k

      So just adding 1k to the price is why it works so well?

      • Matt Grimes

        I guess I’ll shove $1k in the butt stock of my Palmetto and it’ll run 20k rounds.

    • n0truscotsman

      One of my premium grade PSA ARs cost under 700 dollars to build and has 5k through it without malfunctions of any kind induced by the weapon (there was 1 double feed from a USGI aluminum magazine I accidentally stepped on previously).

      Now, I didn’t go 5k without cleaning, but I would clean it irregularly, doing a wipe down with oil every 5-600 rounds. No detail cleaning. I lubricated it with wheel bearing grease and cleaned it with motor oil.

      And did you see the 50k round testing of steel vs brass cased 5.56 ammunition? done with bushmasters.

  • 1911a145acp

    Synthetic high pressure grease will make those locking lugs look waaay better at the 10 k mark.

  • Texas-Roll-Over

    HA 20,000 ROUNDS!

    We had 0 in 50,000. Good luck boys.

  • Nergyl

    20,000 rounds, eh? Impressive.

    Overall I haven’t had particularly good experiences with Colt or Bushmaster ARs. I might have to try out a KAC sometime, though.

  • Cornelius Carroll

    That’s beautiful.

  • TheSmellofNapalm

    Damn son, isn’t running it suppressed gonna foul it up even quicker??

  • Nicks87

    KAC isnt the only company making DI ARs that are this reliable. Let’s not get caught up in the hype. Google “Filthy 14” which is a Bravo Company rifle that has been used for classes at EAG tactical with over 43,000 rounds through it. They had another carbine, #70 that has over 12k through it with no cleaning or malfunctions as well. IMHO KAC rifles are for elitist gun snobs, I refuse to give them a dime of my hard earned money.

    • Uniform223

      I thought H&K was the firearm of choice for elitist gun snobs?

      • John

        Yup, it’s HK but JP is still the best there is. JP owners could look down on both HK and KAC AR owners, but they don’t

        • Nicks87

          I don’t run into a lot of civilians with HK rifles so I can’t really call them snobs. JP guys are as humble as they come.

    • Hank Seiter

      Yep, I remember reading “Filthy 14″ about six months ago. Pretty dang impressive. Bravo Company, Daniel Defense, and Armalite make top-tier ARs. Rock River is just one notch below and is probably your best dollar-for-dollar value, particularly with their often included two-stage national match trigger set-up. I originally owned Colt’s 20” SP-1 and original CAR-15 over thirty years ago (BFA – Before Forward Assist), but frankly I haven’t been too impressed with Colt’s offerings the last twenty or so years.

      BTW, I’m not all that sold on forward assists since I’ve never had an opportunity to save a shooting cycle by slamming the forward assist forward on a balky round. I’d much rather simply clear the round and chamber another. And if you’re chamber is so carboned-up so as to require the forward assist, you simply haven’t been doing proper maintenance and you’re going to be SOL in a rather short time anyway. But I suppose its better to have one and not need it than to need it and not have one under the worst of circumstances.

  • Josh Saintz

    Hey, I might be playing devils advocate here… But having the dust cover closed while you’re getting it dirty isn’t really going to change anything… Sooo… are we supposed to think that dirt/mud on the furniture of the rifle is going to hinder its performance???

  • Aaron E

    I hope they make it! It’s a great testimony of the quality design of a DI AR-15. I’d also love to see a comparison 20k shoot of a piston AR-15. Looking at those parts is hard, kinda like the torture tests out there. Nice to know stuff works after tough actions and conditions, but still hard to see nice firearms go through that.

    If that was my rifle I would break it down at the end, put it in a sonic solvent bath, and leave it for about a month. Forget spray solvents and brushes. Yuk!

    • WV Cycling

      Be wary, some petrol solventd and even simple green can change exterior metallurgy enougb to create weak points. KMC chain company did a test where tgey left bicycle chains in various solvents, and even stuff like gasoline. Many, many of the chains broke way beforebtgeir typical lifespan. YMMV.