Tag Archives: armor

M1 CATTB

The Component Advanced Technology Test Bed was another late 80s American test program to investigate new systems for future tanks. As we’ll see, it looked quite a bit different from the TTB, and where the TTB was testing a very specific change (namely the unmanned, low profile turret) the CATTB tested a variety of new technologies in a more conventional layout.

CATTB

CATTB shared an Abrams hull, but the turret was new, and came with a bustle-mounted autoloader. The autoloader was very similar to the one on the Leclerc or K2. A new gun was tested, the XM291, which came in both 120 mm and 140 mm versions. The 120 mm version provided a lower-risk alternative to the 140 mm. The turret had rather large forward armor arrays, plus reasonably thick side arrays and a decent amount of roof protection. And I have no idea why they decided to mount so many smoke grenade launchers on there, but they did. This was before the advent of soft-kill active protection systems, but might not go amiss on a tank today with the right cueing system.

CATTB Rear view

As you can see from this rear view, the CATTB also came with a new engine: the XAP-1000 diesel. The Cummins/Allison XAP-1000 was based on the advanced Cummins XAV-28 V-12 diesel, a low-heat rejection engine. It used only oil coolant and has no water in the cooling system at all. Higher temperature exhaust gasses were tapped to run the APU. I don’t know a ton about this engine, but the US Army has a history of backing highly advanced diesel engines that end up being problematic. I would suspect similar things with the XAP-1000. Again, the project went nowhere. Later in the 90s, the Abrams was going to get a new engine as an offshoot of the Crusader project, but the proposed engine was not the XAP-1000. Instead, a gas turbine was chosen.

CATTB is a lot more of a conventionally designed tank. I do really like its lines. The project which was supposed to lead to the Block III MBT ended up leading nowhere due to changing priorities. Though, it is not at a museum. It is in the long term storage section of the Sierra Army Depot in Hurlong, CA. Make of that what you wish.

On the 140mm Tank Gun

Let’s talk some more about the 140 mm tank gun, that late cold war weapon that never was. Perfect for killing Soviet Supertanks that never were. And making your new tank way cooler than everyone else’s. The fastest way to get more armor penetration is to just build a bigger gun with more muzzle energy. A lot more.

As you might imagine, a 140 mm round is quite a bit bigger than a 120mm round. Let’s take a look, because these numbers are damned hard to find:

First, a typical 120 mm APFSDS round for the era, the American M829A1. The legendary Silver Bullet that slaughtered the tanks of Saddam’s Republican Guard. Some variations in length and weight are to be expected amongst 120 mm rounds. Newer rounds are a little heavier, but the size is constrained by ammunition storage racks and the existing chambers. The M829A1 is also the round that was in service while the 140 mm was under development.

M829A1 120 mm APFSDS
* Length: 984 mm
* Weight: 20.9 kg (46 lbs)

And now, the round to replace it. Producing 23 MJ at the muzzle, more than double that of the 120mm. The mighty 140. Dimensions were fixed by the NATO countries that were all developing their own versions of the round.

140mm tank round

XM962 140 mm APFSDS
* Length: 1,482 mm
* Weight: approximately 40 kg (88 lbs)

The length and weight of the 140 mm stand out. This round would have been a royal pain to handle. It’s also a bit fatter, so autoloaders could handle fewer rounds. This explains why the K2 Black Panther, otherwise similar to the Leclerc, can only hold 17 rounds in its autoloader compared to 22 in the Leclerc. The K2 is ready for 140 mm, needing only a barrel change. Interestingly, the round count in the Black Panther matches those for the M1-CATTB prototype, which had a similar, belt-style autoloader in its bustle. Don’t worry, we’ll talk about the CATTB in a future article.

NATO-standard 120 mm rounds like the M829A1 are unitary rounds. One big piece, like an oversized version of the cartridges you load into your guns at home. Because of the large size of the 140 mm rounds, these were made as two-piece rounds. Unfortunately, while I can find dimensions for the round’s overall length, I don’t have dimensions for the pieces. Until I can find one to measure myself, we’ll have to make do with some pixel counting/scaling, which yields a length of about 1,024 mm for the upper part of the round, and about 461 mm for the lower part. Which is still big and annoying for autoloader development. Length of the upper part of the round is heavily influenced by the length of the APFSDS projectile. This also would affect a design using a carousel autoloader like the TTB, since carousel (and therefore hull) height and turret height are constrained by the requirement to lift and rotate the rounds into position.

Based on the standards of the day, the 140 mm gun made more than twice the energy of the 120 mm at the muzzle. Of those 23 MJ of muzzle energy in the 140 mm, 14 MJ goes to the penetrator. Running the numbers meant that the 140 mm APFSDS could punch through more than 1,000 mm of RHAe at a ‘battle range’ of 2 km. For comparison, we’ll pull some open source estimates for M829A1, which give it a penetration of 700 mm of RHAe1.

Now, those are some really good numbers2. Of course, there’s a price to be paid. Even with the two-piece construction, everyone working with the 140 mm designed with autoloaders. Which meant significantly reworked turrets for the British, the Germans, and the Americans at a minimum. Plus, ammunition capacity would drop.

Upgunning to a 140 mm round was the simplest way to get a lot more armor penetration capability into a tank. At least from a weapon/projectile design standpoint. It would have required some serious reworking of then-extant designs, but such is life. When the Soviet Union imploded, the armored threat of the projected Future Soviet (super)tanks evaporated, and the 140 mm gun projects were quietly shelved. 120 mm rounds are continuing to get more development and the latest are quite a bit more effective than the M829A1. Lower cost, likely lower capabilities, but this decision makes sense given the circumstances.


  1. There’s some variation in this estimation depending on source. Open source disclaimers apply, etc. 
  2. They’re also a trifle disingenuous. Nobody is armoring their tanks with a meter of rolled homogenous steel. Literally nobody. A more advanced penetrator design can exploit effects on the not-steel that people actually armor their tanks with. Similarly, the armor might be designed to radically degrade (read: break up) the penetrator, which can be sort of but not really captured in RHAe estimations. So the RHAe numbers don’t actually tell the whole story on either side of the design puzzle. Oh, and the numbers themselves are the usual open-source estimates3, so they’re probably all wrong. 
  3. If you’d like to try your hand, start running through the Odermatt equation. And then remember that Odermatt wrote for tungsten-based penetrators, and M829A1 is depleted uranium, so you’ll need to tweak it. 

M1 TTB

The M1 Tank Test Bed (TTB) was a late-80s prototype to test unmanned turret design concepts and compare them to a modern, manned-turret design: the then-state-of-the-art M1A1. The TTB was not necessarily intended to be what the next MBT would look like, but it was intended to shake out some design concepts and see if they were worth considering in the future. So let’s take a look.

m1 ttb

Some of you may notice a resemblance to the T-14. Both use similar unmanned turret design concepts. Such designs have been kicked around since the 1950s by many different groups of tank designers, and all for similar reasons of being able to reduce protected volume (and hence reduce design weight for a given standard of protection). The M1A1 weighs about 57 tonnes. The TTB, with a similar protective standard and the same 120mm gun (and a similar ammunition capacity) was reckoned to weigh about 15% less, for an approximate TTB weight of 48.45 tonnes. Interestingly, this is very close to the published weight for the T-14.

TTB also, of course, reduced crew to three men and put in an autoloader for ammunition handling. The design was intended to improve crew safety by completely isolating the crew from the ammunition. The autoloader itself was a large carousel, holding all ammunition below the turret ring. Let’s look at some pictures.

ttb autoloader

It’s sort of like the autoloader on the T-80, though NATO 120mm ammunition is one-piece, and is therefore a little more annoying to design an autoloader for. The autoloader built for the TTB held 44 rounds and this could be expanded to 48 or even 60 rounds with minor design changes. All of the ammo was stored in a ready configuration because the crew would be unable to move ammunition from a reserve magazine to the autoloader’s ready magazine (as on the Leclerc for example). The TTB autoloader was extensively tested, and could manage a rate of fire of one round every 12 seconds. Spent case bases or misfired rounds were ejected out a small hatch the back. The autoloader could be supplied through the rear hatch, and also had an unloading mode where it could slowly present rounds for removal. The autoloader weighed about 1,400 lbs. empty.

Some might question the vulnerability of such a design. However, statistically the vast majority of tank hits occur to the turret. Tanks like the T-72, for example, ran into trouble because of the ignition of their unprotected reserve ammunition stowage in the turret, not hits that set off ammunition in their autoloaders. And again, complete isolation from the ammunition should keep the crew relatively safe.

The TTB program was dialed back with the end of the cold war and was finally cancelled in the mid 90s. The autoloader design was used in the M1128 Mobile Gun System version of the Stryker.

As for the TTB prototype, it’s at the National Armor and Cavalry Museum at Fort Benning, and has recently been restored and repainted.

Avenger II SHORADs

As mentioned earlier, the US Army is concerned with short range air defense systems again. And they’re looking at various versions of COTS systems to fill this need. We’ve looked at the new Bradley SHORAD vehicle. Now, let’s take a look at one based on the Stryker, called the Stryker Mobile SHORAD Launcher (MSL).

stryker msl

What GLDS has done is cut off the back portion of the regular Stryker to make something flatbedded. Then, they added the turret off of the M1095 Avenger and then Boeing modified that turret.

The M1095 Avenger is a 1980s vintage SHORAD system that put a pair of quadruple Stinger launchers on a turret, and mounted the turret on the back of a HMMWV. Putting the turret on the back of a Stryker gives the turret better all-terrain capability, as it matches the mobility of the rest of a Stryker Brigade Combat Team. Crew protection should also be better. On the other hand, it will be more expensive.

Like on the Bradley SHORAD, the newer Avenger turret is more versatile. Options for each side include the regular quadruple Stinger box, a set of launch rails to accommodate four Hellfire missiles, or a set of launch rails to accommodate three AIM-9X Sidewinders. It also has an improved IR imaging system, which has a laser to guide the Hellfire missiles.

As before, there’s no radar. Both of these launch systems will need some degree of external cueing. A lack of radar does keep the cost down. Depending on expected threats and usage, this may or may not be a severe handicap.

One further usage is on the HMMWV successor, the JLTV. You can still mount this newer, multiuse Avenger turret on light tactical trucks like the JLTV, as seen here at the AUSA expo:

JLTV Avenger

This version has an M230 LF gun instead of one of the missile boxes.

US Army Next Generation IFV Prototype Solicitation

The US Army has started looking for a new IFV to replace the Bradley. Again. They’ve requested a couple demonstrator prototypes to play with. Right now, this is a very early assessment, but the US Army has a few requests.

Things that the Army is looking for in the design include a crew of two, capacity for six dismounts, and a 50mm gun. It will be interesting to see what the design team comes up with.

We’ve been here before. Twice. And we failed both times. The Future Combat System and the Ground Combat Vehicle were both failures. Both programs were hugely ambitious. Future Combat System was supposed to be a massive family of vehicles with lots of commonality and lots of advanced fire control and propulsion systems. Ground Combat Vehicle was supposed to be a big IFV with a number of significant improvements, including a variety of high-end electronics, an advanced propulsion system, and a full squad’s worth of dismounts, i.e. 9 men. Both had huge, unsurprising cost overruns, and both times Congress scored dreaded budget kills on the projects.

Six dismounts keeps the size down, which will keep the weight down, which should help keep the cost down. The GCV had an increasing weight spiral as protection requirements and systems kept changing. A crew of two probably indicates an interest in a remote turret system. Unfortunately, this might also indicate some advanced fire control system needs, which would drive cost up. I’m still impressed that Big Army compromised on something like dismount numbers out of the gate.

Overall, we have something that looks very similar to the German Puma. While it’s an expensive IFV, it has excellent protection. And, the General Accountability Office rated it as cheaper for the Army than either the notional GCV or a Namer APC with appropriate US Army electronics. And that didn’t have the desired firepower.1

Speaking of firepower, that might also strike you as something that stands out. A 50mm autocannon would pack some serious punch, both as far as HE Capacity and armor piercing capability. I would expect something like a modernized 50mm Supershot to be the gun of choice, and the US Army is testing something similar.

Going back to the Puma connection for a moment, SAIC is the prime contractor for the prototypes, and they were also the prime contractor in the GCV evaluation with a design that was a substantially reworked Puma. Perhaps the US Army is also a fan of the Puma.

What do I think, keeping in mind that this is a rough sketch? I really like the sketch. Something like the Puma as far as protection and capacity but with a proper gun would be awesome. I’d prefer it with nine dismounts. But I’d prefer a lot of things. I like that they’re starting with something which seems semi-reasonable on the face of it. I want a high standard of protection and survivability, and if I have to accept six dismounts to keep cost reasonable and avoid the total budget kill, so be it.


  1. I can’t really verify GAO’s work on cost estimates, because the GCV and alternatives comparison report doesn’t go through their methodology. However, their Puma cost estimates match up pretty well with the Puma’s price in the Czech IFV competition, once we account for inflation and currency conversions. In light of anything better2, I’ll stick with GAO’s estimates. 
  2. Primary sources or documented estimates, please. Ideally I’d have budget statements, but I haven’t been able to find those for the IDF or the Bundeswehr. As a side note, I have been able to find them for the US Armed Forces as well as the French Armed Forces. Thanks, Lafayette. 

M1 Abrams Gets A Trophy

I’ve commented here that the M1 Abrams should really get a hard-kill active protection system (APS) fitted. And I’ve held that view for years. I have said this to Fishbreath many times. And each time, I’ve pointed to a certain, existing hard-kill APS as my unit of choice. Israel’s Trophy.

Of course, I’m just an armchair strategist. But I’m not the only one saying this. For many years, the US Army had responded to questions on the APS front that they were working on their own American-made design with a number of manufacturers. And that it was going to be better. Faster. Safer for nearer infantry. Etc. Etc. Made here. Well, millions of dollars in research budget and tons of tests later, no dice. Nothing is ready. Nothing has been mounted on an actual tank for any kind of serious testing.

Screw. That.

Kornet missiles and RPG-29s aren’t going to wait in mid flight and have a couple shots of Stoli while you figure this stuff out. And Big Army has finally come around to the fact that maybe the perfect is the enemy of the good enough, and maybe, just maybe, they should hurry up and get something fielded. Maybe from some staunch ally of ours whose tanks are regularly shot at by Russian ATGMs?

Trophy isn’t a perfect system. But it’s available. Today. Right now. And it’s been proven in combat. It has shot down actual missiles. It works. It’s in production. It’s even reasonably priced.

For the low price of just $350,000, let’s see what we get:

M1 Abrams with Trophy front

And another view:
M1 Abrams with Trophy side view

It’s not a perfect mounting. Those sponsons stick out quite a bit. On the plus side, they might be removable for transport, which would be good. And this is way cheaper than tearing apart the turret and mounting them inside. Unfortunately, I don’t know how much they weigh. Oh well. I really don’t care too much about the weight. Clearly it’s vitally important that the Abrams eats more hamburgers and takes the heavyweight title away from the Challenger 2 TES(H). Turret drive and suspension upgrades are probably long overdue anyway.

Bradley Linebacker Return

If you’ll recall from our earlier discussion of Bradley variants, there were a couple of versions that had short-range air defense (SHORAD) capability. One carried eight of the excellent ADATS missiles in a purpose-designed turret with a mechanically-scanned radar and some new optics for sighting the missiles. When ADATS wasn’t procured, an alternative version was chosen. This one simply replaced the normal box launcher for a pair of TOW missiles on the regular Bradley with a box launcher for four Stinger missiles. This version was called the M6 Bradley Linebacker, but the lack of aerial threat led the US Army to return these to the standard Bradley configuration with TOW missiles.

Of course, recent events in the Donbass have reminded everyone that yes, there is a conventional threat out there, and it might have some aircraft or UAVs that need shooting down. And so a new Bradley Linebacker configuration has been proposed by the cool people at BAE. Behold!

bradley linebacker 2-1

bradley linebacker 2-2

Let’s review the changes. Or the changes beyond the regular M2A4 set. The gun has been switched out from the 25x137mm M242 Bushmaster cannon to the 30x113mm M230LF cannon. This provides an airburst fuse option. There are plenty of airburst-capable 30mm rounds, but none in the 25mm caliber. At least not for autocannons.

The quadpack Stinger launcher has returned. Other options available include a twin AGM-114 Hellfire launcher or a twin AIM-9X launcher. And yes, the AGM-114 can be used in an antiair role; it’s simply a matter of pointing the laser or radar guidance at the airborne target. The twin AGM-114 launcher can be seen at the right of the second photo.

We can also see that this vehicle now has its own radar. These are the four round drums on the corners of the turret. This new Bradley will be able to acquire aerial targets on its own. The radars are configured to handle both search and fire control duties. In addition, the new Linebacker 2 can be connected into an air defense network for target cueing.

Finally, we can see a really tall new array of stuff mounted on top of the turret. This is the British Anti UAV Defense System (AUDS). It combines an additional radar optimized for detecting very small targets, an electro-optical system for observation and identification of said targets, and a directional RF jammer for downing UAVs. Additionally, the 30mm airburst rounds should also be very effective against drones.

All in all, it’s a worthy heir to the Linebacker name, and it should be a very effective SHORAD vehicle.

Namer IFV

I love the Israeli Namer. It’s great. Like Steven Segal, it is Hard To Kill. Its armor is proven effective against the most modern ATGMs. And it can carry a full squad.

But nothing’s perfect. The obvious limitation of the Namer was its firepower. Out of the factory, it came with a remote weapons station with an M2 heavy machine gun. So while it could carry infantry through eight kinds of hell, it couldn’t engage other armored vehicles or provide as much supporting fire as other mechanized infantry vehicles.

Until now.

Those magnificent bastards have done it. They’ve made an IFV version of the Namer. Now with a brand new, unmanned turret! Let’s take a closer look.

Primary armament is a 30 mm Mk. 44 autocannon. The classic Bushmaster II. This is a fine choice, and pretty standard. It’s got 400 ready rounds in a dual-feed system. Unfortunately, I have no information on how the 400 rounds are split up. 30 mm allows the possibility of airburst rounds, and gives a nice volume of stowed ammo. It’s a solid choice on the ammo vs. round size spectrum.

Coaxial armament is a 7.62×51 mm machine gun, with 700 ready rounds. Pretty good capacity, standard choice of armament here.

The turret also contains a pop-up missile launcher. This comprises two tubes for Spike ATGMs. I’m not sure which Spike version is carried, probably -MR or possibly LR. Spike is an excellent modern ATGM that’s similar to Javelin.

But wait, there’s more! The turret also comes with a 60 mm mortar. I haven’t been able to find the capacity for it. The Israelis love mortars, as I do. Their tanks have been equipped with mortars since the Centurion days, when they were retrofitted. This gives their IFVs some indirect fire capability, and anything that gets more mortars (and more firepower) to the troops is fine with me.

The nature of unmanned turrets, and the newness of this model, makes it hard to determine the amount of passive protection. I’d guess from the shape and bulk that it’s got autocannon protection (STANAG level 6), but that’s purely speculation. However, we can clearly see that the turret is equipped with radar and effectors for the Trophy active protection system. There are also the usual smoke grenade launchers at the front.

Sensors are also pretty standard, though details are scarce. There’s an optics array for the gunner, and a separate, independently-rotated unit for the commander. I’d expect laser rangefinders and thermal viewers for both, but I don’t have data on the generation of the thermal units, magnification levels available, or the laser type for the rangefinders. I’d also expect computerized fire control systems, but the details aren’t available yet.

This is actually pretty close to my ideal IFV sketch. I love it. I’d buy in a heartbeat. As should the US Army. A large number of Namers are built at the General Dynamics Land Systems factory in Lima, Ohio. There’s no reason why the GCV couldn’t have looked much like this, and there’s no good reason why this shouldn’t be bought in lieu of the failed GCV.

It looks like Hanukkah has come early this year.

Engines for Armor: AVDS-1790

The AVDS-1790 is the descendant of the 1950s vintage AV-1790, from the days when American armored vehicles still used gasoline engines. It was redesigned to use diesel (the “D” in the initials) and use a supercharger (the “S” in AVDS) for more power. The supercharger has been replaced by a twin-turbocharger setup, and the engine has been refitted with modern, computer-controlled, common-rail fuel injection. Continental Motors, now a division of L-3, currently offers the AVDS-1790 in 750, 950, 1,050, 1,200, and 1,500 horsepower versions. The Israelis are big fans of the AVDS-1790, using it on most versions of the Merkava and on the Namer, as well as on their M48 and M60 tanks.

Note that the -1790 in the model number refers to the displacement of cubic inches1, not the horsepower or the torque.

At first glance, the AVDS is somewhat odd. It’s a rather big V-12 diesel. Yawn. It’s notably bigger than the other diesels you will find. But there’s a reason for that: the AVDS-1790 is air-cooled.

Air cooling provides some noteworthy advantages and disadvantages. The engine must be physically bulkier, because air cooling must be attached to the cylinders directly. You can’t pipe heat to a separate radiator. Liquid cooled engines will also see a higher amount of power for a given displacement. Liquid cooled engines are also easier to meet emissions targets with.

On the other hand, air cooled engines are lighter overall. They are significantly simpler, because there are no pumps. Further, and this is important for combat vehicle designers, they are more robust. Damage to cooling for one cylinder will not affect cooling from the other cylinders. The nature of an air-cooled system means it’s a lot easier to maintain, since the fins on the cylinders don’t need much in the way of maintenance.

The maintenance and ruggedness are what endear these engines to the Israelis. I’d be interested to learn more about the intake system on the Merkava, since this is a front-engined tank without the usual large amount of grillwork on the engine bay, and yet the air-cooled engines still work well.

I think most telling for the quality of the design is that having gone to the MTU883 in the Merkava IV, because a 1,500 hp version of the AVDS wasn’t designed yet, the IDF went back to the AVDS-1790 for the Namer.


  1. As is right and proper. Suck it, metric system. 

Unmanned Autocannon Turrets

There’s a big interest in remote weapons stations for machine guns, since they let you use the guns without exposing yourself to enemy fire. Their bigger brothers, unmanned autocannon turrets, are also increasing in popularity, because they’re a cost effective way to add firepower to vehicles. Let’s look at some options. Alas, costs are unavailable, so you’ll just have to guesstimate.

EPOCH
First, Russia’s Epoch turret. It’s used on the T-15 Armata Heavy IFV, plus the Kurganets IFV, and could probably be retrofitted on to other things. It’s got a 30×165 mm autocannon with 500 rounds of ready ammunition (dual feed with one 160 round box and one 340 round box), a 7.62x54R mm machine gun with 2,000 rounds of ready ammo, and four Kornet-EM ATGM tubes. The gunner has a day/thermal sight with laser rangefinder. The commander has an independent day/thermal sight with laser rangefinder as well. I do not have information on whether or not these are Gen 3 thermal sights. No secondary remote weapon station is fitted for the commander. Epoch is not protected against autocannon fire. It is fully (i.e. biaxially) stabilized. Eight smoke grenade launchers are fitted. It is capable of high-elevation fire. It does not appear that reloading the turret is possible from under armor. Also, even though it lacks armor, given it’s bulk and ammo reserves, I would expect it to be heavy. Also, relatively expensive. But it does have the most firepower of any turret on our list.

MCT-30
This is the turret that the US Army is fitting to some of its Stryker vehicles for more firepower. It’s made by Kongsberg, out of Norway, and it has a lot of options. The gun is a 30×173 mm autocannon, with 150 rounds of ready ammunition (dual feed with a pair of 75 round boxes). There’s also a coaxial 7.62×51 mm machine gun with 600 rounds of ready ammo. ATGM launchers are available as an optional extra. The gunner’s sight is the usual day/thermal with laser rangefinder. An independent commander’s sight, or a Commander’s Remote Weapons Station, are available as optional extras. The basic turret has negligible protection, but the turret can be provided with protection against up to 30 mm autocannon rounds (STANAG Level 6) as another optional extra. High-angle fire is another optional extra feature, as are threat detection systems and active protection systems. All versions can be reloaded from under armor. We’d expect weight and cost to vary significantly based on desired feature set. It’s not a bad turret, but we wish it could accommodate more autocannon ammunition. A pity that’s not another optional extra. Full stabilization is standard.

Samson RCWS-30
This is an Israeli turret, currently in use on the Czech Pandur II. It’s very barebones, without any kind of protective shell. It comes with 200 rounds of 30×173 mm (in a 140 and a 60 round box), a 7.62×51 mm machine gun with a 460 round box, and a pair of tubes for Spike ATGMs. The turret is fully stabilized and a commander’s independent sight is available. A commander’s remote weapon station is not available. There are no protection options available for this model. On the other hand, it’s only 1,400 kg ready to fight. Also, since it’s an exposed gun and feed systems, it can be fitted with any other autocannon system. Conceivably, one could also increase the ammunition capacity, but that might require more powerful traverse and elevation motors. It is capable of high angle fire as well. This is probably my favorite turret from an ‘add more firepower’ standpoint, since it’s light, cheap, and provides balanced firepower.

Lance-RC
The unmanned version of the German Lance turret, the -RC variant is very nearly identical to the turret mounted on the Puma. It comes with a 30×173 mm gun with 200 ready rounds (dual feed, but I haven’t found box sizes), a 7.62×51 mm coaxial machine gun (probably about 650-700 rounds based on the Puma’s capacity for 5.56), and the option for a pair of Spike missiles. It’s got STANAG Level 6 protection out of the box, and excellent optics for the gunner and an independent sight for the commander. It can also be fitted with additional cameras to improve situational awareness or a laser-based jamming system as part of a soft-kill APS. As you might expect, it’s heavy and expensive. But it’s also very nicely equipped.

Of the NATO compatible turrets, what you’re trying to do will determine which you buy. Platform and transportability requirements will also impact your decision.