When asked why he had chosen to send cluster munitions to Ukraine, President Joe Biden had a very simple response: “The Ukrainians are running out of ammunition.”
While the statement is highly unlikely to be true in the most literal sense, there are good reasons to be concerned about the stocks of the critical 155mm howitzer ammunition that now largely fuels the Armed Forces of Ukraine.
Cluster munitions—155 mm DPICMs (Dual Purpose Improved Conventional Munitions)—are controversial due to the risks they pose to civilians. They are also likely to largely resolve Ukraine’s artillery shell needs in the next one to two years, possibly longer … if necessary.
RELATED STORY: Ukraine Update: U.S. agrees to send cluster munitions to Ukraine
what are 155 mm shells? why are they important?
The 155 mm is a type of howitzer shell; 155mm refers to the width of the shell, or 6.1”. For example, the American M107 shell is the standard high explosive shell of the U.S. Army; weighing in at 43.2 kg (95 lbs), it is one of the basic building blocks of firepower in NATO armies.
At the opening of World War I, France’s artillery arm was primarily built around the 75 mm howitzer as its standard field gun. The British 18-pounder (84 mm) was its primary field gun. By contrast, Germany opened the war in 1914 with arguably the best artillery arm in the war, with substantial numbers of powerful 149 mm howitzers that proved significantly more powerful than anything the Allies could initially put in the field.
During WWI, both sides experimented with larger types of artillery of 200 mm or greater, but an approximate 150 mm~160 mm gun proved to have the best balance of mobility, range, firepower, and cost.
France developed 155 mm artillery by 1916, which quickly proved extremely popular among the Allied powers, with the U.S. adopting 155 mm by the end of the Great War.
After WWII, NATO-bloc nations adopted the 155 mm shell as the standard artillery shell of NATO Allied Forces, Although some NATO-bloc nations still field the smaller 105 mm artillery shell, the overwhelming majority of NATO artillery rely on the 155 mm as its standard ammunition. Almost all self-propelled artillery for NATO-bloc nations uses 155 mm artillery, including the best Western artillery systems provided to Ukraine.
- M777 towed howitzer
- FH70 towed howitzer
- M109 self-propelled howitzer
- CAESER 6x6 self-propelled howitzer
- PzH2000 self-propelled howitzer
- AHS Krab self-propelled howitzer
- ShKH Zuzana 2 self-propelled howitzer
- AS-90 self-propelled howitzer
- Archer Artillery System self-propelled howitzer
Per Oryx, there have been 528 completed deliveries of 155 mm artillery pieces (212 towed, 316 self-propelled), with another 52 promised or ordered self-propelled 155 mm howitzers awaiting delivery. This is only a partial picture, as NATO forces also make use of 81 mm/120 mm mortars, and rocket artillery systems like the HIMARS.
Former Soviet bloc nations, including Russia and pre-war Ukraine, employed the 152 mm heavy howitzer and 122 mm light howitzers in large numbers, although Russia was transitioning to a greater focus upon solely 152 mm artillery.
Ukraine’s artillery arm was heavily reliant on Soviet artillery early in the war, but has increasingly transitioned to NATO (that is, 155 mm) artillery as the war has gone on. Ukraine faced issues from an early stage in obtaining Soviet artillery ammunition, as most allies utilized NATO-standard artillery.
Furthermore, NATO artillery offers options in greater quantities for more advanced munitions. Rocket-assisted projectile rounds are extended-range, unguided shells that can strike 30 km-40 km away (as opposed to a standard round that usually is limited to 20-25 km or thereabouts).
They can also fire BONUS or SMArt rounds—guided anti-tank munitions that can strike enemy armor from 20-30km away. Some of the deadliest 155 mm munitions include GPS-guided munitions like the M982 Excalibur, which can strike targets up to 50 km away with deadly accuracy.
While GPS-guided munitions are important, they are available in limited quantities and cost $70-$100K per round, whereas the standard unguided M795 shell is just a few hundred dollars. These standard unguided shells are the workhorses of the Ukrainian military. Ukraine fires thousands of these shells a day, and during heavy offensives, Ukraine is believed to consume upwards of 10,000 shells a day or more.
Ukrainian 155 mm Shell Usage
Ukraine has been open about its need for more 155 mm shells, calling on Western allies to do more to keep up with its needs.
On March 3, Ukrainian Defense Minister Oleksiy Reznikov sent a letter to all 27 member states in the EU, stating that the Ukrainian military was not receiving the shells it needed. Reznikov asked the EU to provide Ukraine with 250,000 shells per month. Reznikov also provided information about how many shells Ukraine was using and how many it needed.
Reznikov stated that the Armed Forces of Ukraine were using 110,000 shells per month—a suboptimal total. Reznikov said that the ideal shell usage for Ukrainian forces was “356,400 shells per month,” or a little more than 10,000 shells a day (this figure matches estimates for Ukrainian shell consumption during major offensives from September-November 2022). Reznikov also commented that if all constraints on Ukraine’s firepower could be lifted, Ukraine could make use of “594,000 shells per month.”
What is deeply concerning is that allies’ production of 155 mm shells currently does not even approach the 110,000 figure.
The United States’ 155 mm shell production capacity is only 14,000 shells per month. As a result of the sharply increased demand for shells, the U.S. has made a major investment in shell production and is expanding production to 24,000 per month by late 2023, with production to be increased to 85,000 per month by 2028.
There are also numerous EU-based manufacturers that produce bulk quantities of 155 mm ammunition: BAE Systems (UK), Expal (ESP), Santa Barbara Sistemas (ESP), Explosia (CZE), Nexter (FRA), Nammo (NOR), and Rheinmetall (GER). Their combined production capacity is estimated at 45,000-50,000 shells per month. The EU is also investing in expanding arms production, but faces significant challenges in dramatically expanding production in the short term.
The problem is pretty clear. The U.S. and the EU combined only produce around 60~65K shells per month.
This 65K must be compared to Ukraine’s actual usage, which is around 110K, and is even further short of their stated ideal of 356K shells.
Other allies are working to assist. Japan’s pacifist Constitution sharply restricts its ability to supply lethal aid, but it’s supplying large quantities of TNT that form the raw materials for shell manufacturing. As a workaround for opposition to provide lethal aid to a belligerent, South Korea sold 500,000 shells to the U.S., so that Americans could provide their stocks to Ukraine without impacting readiness.
Other avenues to boost production are being explored. Rheinmetall Denel Munition, a joint German-South African subsidiary and munitions manufacturer, began manufacturing guided munitions and rocket-assisted long-range shells in March.
All told, the EU has sent an estimated 350,000 shells to Ukraine, while the U.S. has sent around 1.5M as of May. Most of these shells have been procured by gathering up stockpiled shells, rather than newly manufactured ones. Based on ammunition deliveries reported and U.S./EU production capacity, a further 120~130,000 shells were likely delivered—a total just a little short of roughly 2M shells.
Ukraine began first receiving 155 mm artillery in May 2022, or about 17 months ago. Shell consumption was likely lower in those first months before it began receiving major shipments of 155 mm howitzers in the fall. If we assume consumption of 30,000 shells per month from May to August, then 110,000 shells per month thereafter, Ukraine may have consumed around 1.6M shells, leaving a stockpile of only around 400,000 155 mm shells, or about a three-month supply, assuming Ukraine is being quite judicious with its artillery.
Even if NATO nations continue to send essentially their entire production capacity to Ukraine, the shortfall of 50,000+ shells would consume what remains of Ukraine’s 155 mm stocks by early spring 2024—or sooner, if Ukraine’s shell consumption has accelerated after the beginning of the counteroffensive, which it almost certainly has.
if Ukraine is using say, a 50% increase over its March usage, that would be 165,000 shells per month. If the estimated stockpile of 400,000 shells is correct, Ukraine would run out of shells by the end of October, barring an infusion from other 155 mm artillery shell sources.
And so the U.S. cluster munition stockpile, especially the DPICM 155 mm shells, is a game changer. Yes, they are powerful weapons, and yes, they are likely to substantially help Ukrainian artillery capabilities. But they are also likely needed to avert a potentially disastrous Ukrainian shell shortage. Conversely, providing Ukrainian forces with ammunition from the U.S. stockpile is likely to entirely avert a shell crisis for at least the next two years of conflict, possibly longer—if necessary.
The 155 mm DPICM Shell Stockpile
The Biden administration has confirmed that the DPICM 155 mm artillery shells, presumably the M483A1, will be sent to Ukraine. 10,000 of the shells were already stationed in Europe, and are already on their way; they will arrive at the front line within days.
These shells each contain 88 small explosives (grenades or bomblets) that blanket a targeted area, In field testing, they recorded a dud rate of around 2.5%, which is probably where National Security Advisor Jake Sullivan’s comments about only providing cluster munitions with a 2.5% dud rate or less came from.
The U.S. has a massive stockpile of these munitions. Department of Defense reports indicate that the U.S. Army and Marine stockpiles of DPICM shells amount to 402M submunitions. At 88 submunitions per shell for the ubiquitous M483/M483A1 shells, there would be at least 4.6M DPICM 155 mm shells. There are likely to be slightly more, since the stockpile includes a smaller number of M864 DPICM 155 mm shells with only 62 submunitions, but a longer range of fire.
So somewhere around 4.6M~4.7M shells is likely to be a fair estimate for the size of the U.S. stockpile. These 155 mm DPICM shells collectively are said to have a failure rate of around 2.5% to 3%, and are likely the munitions the Biden administration plans to send.
Simply adding a million shells to Ukraine’s available ammunition supply is, again, an obvious gamechanger. If Ukraine’s shell consumption is around 170,000 per month, the shortfall relative to production is about 100,000 shells. A million shells would help cover 10 months; 2.4 million shells, roughly half of the U.S. stockpile, could cover two years of conflict.
If Ukraine were to increase its shell consumption to 360,00 shells for the next three months, then drop back down to 110,000 shells by year’s end, it would presumably take about a million additional shells—which might be feasible, if the Biden Administration chooses to release that number of shells.
Furthermore, by December, U.S. monthly production should have risen to 24,000 shells (from 14,000). The EU pledged to increase its 155 mm shells produced and provided to Ukraine to a million shells a year, which would add 83,000 a month. If shell production reaches 107,000 shells per month, Ukraine’s shell consumption at least becomes slightly less draining on its stockpiles.
These calculations treat the DPICM shells as if they are ordinary shells—but they are much better.
One of the key findings from research on the effects of cluster munitions has been the fact that they are dramatically more effective at striking entrenched infantry positions.
When using conventional artillery shells to strike enemy infantry in a trench, the artillery needs to make a near-direct hit on the trench position. This requires considerable trial and error, which consumes considerable ammunition.
A DPICM works like a shotgun, landing submunitions in a broader area, making it dramatically likelier to hit one or more entrenched infantry positions. Field tests indicate that DPICM can take the place of as many as five to 15 conventional artillery shells when used against entrenched infantry positions.
If we are conservative, and assume that one DPICM shell can take the place of three conventional 155 mm shells, the “360,000 shells” estimate suddenly looks more attainable. If Ukraine uses 100,000 conventional shells per month (drawing 30,000 shells from stocks monthly, a more sustainable burn rate), to reach the “360,000 shells” figure, Ukraine needs about 260,000 shells worth of DPICM shells—or about 87,000 a month.
Given that the U.S. has around 4.6M such shells stockpiled, providing 80-100,000 DPICM shells a month for six to seven months should be more than feasible.
There are numerous other weapons in the U.S. stockpile of cluster munitions. In particular, the Rockeye Antitank Missile has been proposed by Ukraine specifically. Furthermore, the DPICM warhead GMLRS missile and the ATACMS Block 1 for the HIMARS system appear to be natural fits for Ukraine’s military capabilities and needs. This is a topic I intend to explore more fully in Sunday’s Ukraine Update.
Even the DPICM 155 mm shells alone would be a way that the U.S. could provide Ukraine with the firepower that it has been seeking but were previously kept out of reach by long-standing shell supply constraints. DPICM would provide Ukraine with a quantitative advantage in sheer firepower that it has thus far never enjoyed on the battlefield.
The DPICM shells will make Ukrainian artillery significantly more effective
The benefits of DPICM cluster munitions will not simply be quantitative, however. The DPICM shells have several major advantages over their conventional counterparts, including
- a faster kill chain;
- better resilience against counterbattery fire; and
- less logistical burden.
A kill chain is a military science concept that describes how military forces eliminate enemy targets. Regardless of the weapon system used, a 4-step sequence is used:
- Dispatch (of assets necessary to attack)
- Initiation (of the attack)
Sometimes, this process is abbreviated or simplified. For example, take a sniper that sees a target walking down the street and fires a bullet.
- Identification: Sniper sees the target;
- Dispatch: Sniper is already in place;
- Initiation: Sniper aims and shoots; leading to
The kill chain in the case of a sniper might take all of two to three seconds. But in the case of artillery, the process can be considerably more complicated.
- Identification: A Russian trench position is identified by a reconnaissance drone;
- Dispatch: 155 mm artillery and a spotter drone move into an offensive position;
- Initiation: Artillery fires. Spotter drone calls out adjustments to fire until the artillery hits, resulting in
It might take dozens of rounds of artillery fire to eliminate infantry holed up in a trench.
Cluster munitions, however, accelerate the kill chain by making it faster to move from Initiation to elimination. That is, it can eliminate the infantry while firing fewer shells. For example, the accuracy of Ukrainian artillery striking this Russian trench position north of Bakhmut is highly impressive.
However, from the numerous black marks on the ground near the trench, it is obvious that Ukrainian artillery were firing at this position for some time. To “obtain the range” of the target, a process of trial and error was conducted.
For example, an M777 155 mm howitzer can only fire two to three rounds per minute in a sustained manner; to fire 10 rounds at a trench, it can easily take four minutes or more.
In that time, Russian infantry may move to a different part of the trench or otherwise shift the weight of their defenses, making continued attacks on the trench by the M777 meaningless. This type of movement is called “breaking the kill chain,” by making it difficult for the weapon to follow up.
Cluster munitions greatly simplify this process. By firing a single cluster munition, the M777 can blanket the target with submunitions, catching even infantry protected by the trench, with only a few rounds. The speed of the kill chain makes it harder for the Russians to react defensively in an effective manner, making a kill more likely.
Furthermore, every minute a howitzer stays in place is another minute the howitzer can be targeted by enemy counterattacks—whether counterbattery fire from Russian tube or rocket artillery, or whether the artillery becomes targeted by a loitering munition, such as a Lancet drone.
Thus cluster munitions like the DPICM shells also improve survivability for Ukrainian artillery crews, since faster completion of their mission objective allows them to relocate faster—helping to break the Russians’ kill chain.
Another underrated factor? The way cluster munitions can alleviate logistical burdens. If three DPICM shells can do the work of 10-12 conventional shells, DPICM also represents massive improvements in cost-benefit for transportation tonnage to the front.
If an artillery unit can accomplish its mission with 500 DPICM shells instead of 2000 conventional shells, Ukraine can use that precious transportation capacity to bring up something else that’s more needed—or to simply bring more DPICM shells to the front to further increase the firepower of Ukrainian artillery crews.
DPICM shells will also help alleviate the logistical burdens of frequent barrel replacements for Ukrainian artillery units. A high-quality howitzer barrel can sustain 2-3,000 rounds of fire before requiring replacement. However, there is a deterioration of accuracy in the later stages of a barrel’s life, which has led some Ukrainian crews to replace barrels after only around 1500 rounds. This creates a logistical strain as Ukrainian chew through stockpiles of 155 mm gun barrels.
If a gun can complete its mission with five rounds of fire, instead of 15-20, it subsequently reduces the barrel wear imposed upon an artillery unit, reducing barrel replacement needs relative to firepower.
The 155 mm DPICM is a necessity, not a wonder weapon
The 155 mm DPICM shell is not a wonder weapon. It will not clear Russian trenches with the wave of a wand, and it certainly is not a solution to Russia’s dense minefields that have proven so difficult for Ukrainian forces to deal with in the counteroffensive.
In a sense, it simply does things that Ukrainian artillery is already capable of doing—just faster. And hopefully, it can get more done.
The main advantage that giving Ukraine DPICM shells offers is averting a shell crisis. With well over four million shells in stockpiles, the U.S. can give massive quantities of DPICM shells to Ukraine, while barely making a dent in its stocks. it must be emphasized these are stockpiles of weapons that the U.S. has not used in any significant quantity in 20 years.
Furthermore, access to four million stockpiled shells would provide Ukraine with the opportunity to bring the ideal volumes of firepower it envisions against Russian front-line positions for the first time.
Providing 3040,000 such shells a month would go a long way toward maintaining shell reserves until production increases can be achieved by the end of this year. I would hope that the U.S. would provide as many DPICM shells as Ukraine asks for, to accelerate Ukrainian firepower to those levels it hopes to achieve.
In that sense, 80,000 DPICM shells a month does not seem at all unrealistic. From May 2022 to May 2023, as noted above, the U.S. reported providing 1.5M 155 mm shells of all types—approximately 125,000 155 mm shells of all types per month. Assuming that the U.S. is sending its available production of 14,000 shells monthly, it’s unlikely that the number of guided munitions like the BONUS round or the Excalibur round adds more than a thousand shells to this monthly total. Adding 80,000 DPICM shells would take the monthly total to a little under 100,000 shells, coming in under the average past U.S. contributions.
There are potential other sources of 155 mm shells. Perhaps the U.S. can arrange purchases of additional conventional shells from other 155 mm manufacturers, particularly South Korea or Israel. However, both nations remain politically reluctant to provide direct aid or to export lethal arms to a belligerent, or to offend Russia.
As previously noted, Japan does not manufacture 155 mm shells directly, but it may be possible to purchase some of its stock of 155 mm shells in a rotation scheme, where U.S. shells are sent to Ukraine, and Japanese shells replace them in U.S. stocks—but many American allies, like Japan and especially Taiwan, remain wary of reducing their own military readiness due to concerns over potential Chinese aggressive military action.
Other sources of 155 mm stocks have largely already been tapped to some extent. The U.S. began sending munitions from domestic stockpiles of 155 mm ammunition and has now accessed both those stored on the Korean peninsula (for East Asian operations) and those stored in Israel (for Middle Eastern operations).
Even if the U.S. manages to procure some additional shells, it appears likely that U.S. contributions to Ukrainian artillery shell ammunition would drop precipitously without 70-80,000 DPICM monthly or more. It’s unknown how many DPICM shells the Biden administration is planning on sending monthly, but it appears likely that they will arrive in substantial numbers.
This is why DPICM shells are likely to be more of a necessity than a luxury. Without DPICM shells, Ukraine could see a precipitous and dangerous drop in its remaining store of 155 mm ammunition within a few months. However, if the U.S. supplements its ammunition deliveries by adding DPICM shells, the qualitative advantage of the shells may mean that, if the U.S. provides similar numbers of shells as in the past, it could end up representing a substantial increase in Ukrainian firepower.
What could Ukraine do to Russian trench systems with 80,000 DPICM shells a month or more? What could Ukraine do if it began to approach its self-stated ideal levels of artillery firepower?
It’s something I hope we find out in the next few months.