Sherman IC Firefly

The most effective version of Sherman against German heavy armor was a British modification.


Let’s take a look at the Firefly.

The Sherman was a capable enough medium tank. But through 1943 it became obvious a bigger gun was needed against certain opponents.



The British 17 pounder (3 inch or 76.2 mm) was the best anti-tank gun in use by the western Allies.  It could even defeat a Tiger or Panther from any angle at over a kilometer.  I’ve seen it rated as better than the standard German 88 but not quite as good as the 88 mm Pak 43 (used in King Tiger, Jagdpanther, Elefant).
The initial plan was to mount the 17 pdr on the next generation of British tanks.  But both advanced vehicles, Challenger and Cromwell had development issues (Ultimately the Cromwell got an improved 75 mm gun, that was slightly less capable than the 17 pdr).  And by late 1943 it was obvious something was needed quickly; especially when it was realized in Italy that the Panther was becoming a standard medium, not just a special heavy like the Tiger.  The Sherman was the biggest tank, with the biggest turret ring of anything in wide use. But mounting the 17 pdr on a Sherman was not a decision arrived at lightly.  The Army’s Ministry of Supply wanted it on a British tank, not something Lend-Leased.  So that’s where official work was done for quite some time.
Major George Brighty of the Royal Tank Regiment wanted something quicker and started his work on mounting the gun to a Sherman.  Even though its ammunition diameter only slightly exceeds other Sherman guns, the barrel length is much greater and the recoil is an impressive 40 inches.  That recoil is simply too much for a standard Sherman turret.  Brighty first came up with a fixed mount, that is no recoil on the gun, that transmitted the shock through the whole tank.  But this drastically increased wear on brakes, suspension and transmission.
Brighty was joined by another officer, Lt Col George Witheridge who came up with the idea of a new recoil mechanism that transmitted the force to a sideways mount to take advantage of the Sherman’s wide turret.  At about this time the Army ordered them to cease and desist…  in the vast wisdom of higher ups who aren’t operational.
Fortunately for all concerned, Brighty and Witheridge were able to appeal to some higher ups with Africa experience who ultimately got the decision reversed and this finally led to official interest.


The grey paint on the barrel was a sort of camouflage applied after the Germans began singling out “long barrel” Shermans.  In many conditions it does make the gun look shorter.

The conversion was more complicated than the American 76 mm gun was.  In fact, the 17 pdr was specially produced for weight and balance reasons specific to the Sherman, a new mantlet was needed, radio equipment had to be removed from the turret and a new armored bustle was designed for radios further back, and the bow gunner’s position was removed for additional ammunition storage (the 17 pdr round was much longer than other weapons’).
Initially all Shermans converted to the new standard were Sherman Mk V (M4A4) with the standard 75 mm gun.  But when new deliveries switched over to the 76 mm gun the Army decided to convert older Sherman Mk I (M4).  In British Army nomenclature the 17 pdr was coded by a capital “C”, so the re-manufactured tank was listed as a Sherman VC or IC.  The nickname “Firefly” was soon attached because of the large muzzle blast from the gun.  Gunners and commanders were trained to blink when firing to avoid being blinded by their own gun.  A number of M10 Tank Destroyers were similarly modified with the 17 pdr and were also, often called Fireflys.


For normal driving the turret was faced aft.  This avoided embarrassing accidents of wrapping that long barrel around a sneaky tree or lamp post.  There is also a travel lock at the far left rear of the upper deck.  This is to take the load off the gun’s transport mechanism during long road trips.

Some 2200 Shermans were modified as Fireflys.  By D-Day armored Divisions and Regiments had one Firefly for every four regular Shermans or Cromwells (units equipped with Churchill Tanks had a similar number of M10C Fireflys).  The tanks with other guns were retained because there was no high explosive ordnance for the 17 pdr.  In most cases the standard tanks would advance and combat soft targets while the Fireflys maintained over watch.  They trained in a highly mobile form of over watch because of the Firefly’s tendency to ignite its surroundings when firing.
It didn’t take long for the Germans to realize that the new “long barrel” Shermans were by far the greatest threat to their heavy armor and make them the priority target.  Being a Sherman it was never the most heavily armored AFV on the battlefield, so getting the first shot was important.


Progression of common wartime tank guns.  See the two pounder (40 mm) on the Matilda in front, a six pounder (57 mm) on the Crusader and the 17 pounder on the Sherman

Several battles after D-Day showed how decisive Fireflys could be.  When the Germans launched a counter-attack with 12 Panthers on the village of Norrey-en-Bessin there were 9 standard Shermans and a Firefly defending.  The Firefly, commanded by Lt GK Henry. knocked out five Panthers with six shots.  The remaining Shermans got two more in the successful defense of the village.
Similar shooting from a Firefly commanded by Sgt Harris of the 4th/7th Dragoon Guards destroyed five Panthers with five shots during Operation Perch.
Perhaps the best known success was on August 8, 1944. During Operation Totalize a German counter-attack involving Tigers was defeated by ambush.  One Firefly, commanded by Sgt Gordon, knocked out three Tigers.  This skirmish also led to the death of Michael Wittmann, the feared Tiger commander who had previously held off an entire British Armored Division with only his own tank.


Sherman family photo.  The basic M4 (Sherman I) is right front.  The Sherman IC is a modification of this.  The M4A3E8 in back shows the final American version of the tank.

Interestingly the Firefly became less important in 1945 as German heavy armor became less common.  The standard tanks with their high explosive shells were more needed.  Many of the type’s “bugs” were never fully resolved as it was always viewed as an expedient. And of course post-War, the Ministry of Supply finally got their way with a more British tank to carry their prized gun.


The Panther and Tiger are the two tanks the Firefly was meant to counter.  Its gun was superior and could defeat either with a single shot.  Obviously taking hits was more of a problem.  But sound British tactics (put the non-Fireflys in front!) meant they actually had a lower loss rate than other allied tanks.

This particular example is a Sherman IC attached to the 11th Armored Division.  My information only tags it as 1944, no specific dates or engagements listed.  Most Fireflys were VC models.  But this is one of those limitations of scale, its the Tamiya kit and a modification of their basic M4 kit.  Since they never did (or haven’t yet!) an M4A4 there is no Sherman V.  Obviously not a huge deal, except I believe those famous battles around Normandy were mostly fought by Sherman VCs, with the IC coming in later as replacements.

About atcDave

I'm 5o-something years old and live in Ypsilanti, Michigan. I'm happily married to Jodie. I was an air traffic controller for 33 years and recently retired; grew up in the Chicago area, and am still a fanatic for pizza and the Chicago Bears. My main interest is military history, and my related hobbies include scale model building and strategy games.
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16 Responses to Sherman IC Firefly

  1. Pierre Lagacé says:

    John Knifton will like this one Dave…

  2. ericritter65 says:

    Hey Dave, love the models! What scale are you working in? I’ve had this idea in my head to do simple, clean, factory painted tanks from all the major players in WWII and line them up by size. I just think it would be really interesting to see the changes from pre- and early war to war’s end. Thanks!

    • atcDave says:

      Thanks Eric!
      These are all 1/48. It’s a nice size, good combination Of being big enough to see detail, but small enough to simplify a lot and not take a ton of room. The biggest failing is its supported mostly by just one brand (Tamiya); which, while excellent kits, does limit availability and completeness an issue. So no Stuart or Lee, nothing Italian or French or Japanese. But lots of German stuff…

      If you’re REALLY into armor 1/35 might be better. Certainly more variety, almost anything you can think of is likely available. Although each subject will be bigger, and correspondingly more expensive and time consuming to build.
      If you prefer smaller there is some selection in 1/72, HO, and miniatures scales.

      I’ve got an idea, I’ll try to put up something with some real world size comparisons tomorrow.

      • ericritter65 says:

        Yeah, I like the 1/48 size for vehicles, but choice is restricted, and 1/35 is going to be expensive. Might look at 1/72 for compactness of this particular project – which is just a pipe dream at the moment!

      • atcDave says:

        Sounds like a fun project though. Be sure you post pictures!

  3. J. Allseits says:

    Few realize tank-on-tank combat did not exist till WW2. So tank-on-tank guns didn’t either. Pre-war tank design was still based on support of the infantry, in destroying “soft” targets like bunkers and mg-nests. So common low velocity, high explosive guns were “old-school” tech…

    • atcDave says:

      The Spanish Civil War had really started the arms race though. At least Germany and the Soviet Union had started developing what we would call modern tanks with anti-tank capability. At the start of WWII there still weren’t many of them!

    • Ernie Davis says:

      I think a lot of people saw the possibility of tank on tank combat, but until it really started happening with actual tanks the learning curve was pretty flat.

      For instance a lot of early tanks, many considered to be very good tanks, used riveted armor at the start of the war. Then tanks and anti-tank guns started hitting other tanks with high velocity rounds they realized the rivets could be just as deadly to a crew as the enemy fire without a shot even penetrating the armor.

      • atcDave says:

        Yeah like the Panzer 38(t). Considered a good reliable medium tank at the start, but that riveted armor was a big problem!

  4. Pingback: Sherman IC Firefly – My Forgotten Hobby III

  5. Ernie Davis says:

    Yes, even with the impressive new gun the Firefly was still a Sherman as far as the defensive armor is concerned. It was never a bad as often portrayed, but clearly never expected to face anything like the firepower of a Tiger or Panther when designed, and never really meant for tank on tank combat as that wasn’t really ever part of the American doctrine.

    Still, I did find this interesting account of how effective the Sherman could be when used properly by experienced crews.

    • atcDave says:

      That was really excellent, Thanks Ernie!
      I love how he proves the lie of Shermans always needing superior mass to win. Training, experience, and the advantages the Sherman actually had could make a formidable force.
      No doubt, Allied tankers might have often WISHED for something a little more capable, but the Sherman was adequate when well used.

      • atcDave says:

        Just came across some fascinating data in Stephen Zaloga’s latest book on “Tanks in the Battle of Germany”.
        Obviously this means the tail end of the War, and German overall situation was catastrophically bad. But after the Ardennes Offensive the best couple German armored units were transfered back East, that left the Western front with some 3300 AFVs in January 1945 and 1600 a month later. That February total includes a total 26 operational Tigers, in April that number was 10. Ratio-wise it meant the Allies had a 18 – 1 AFV advantage in February and a 60 – 1 AFV advantage by April.
        But what I found really fascinating was a British survey done right after the War rating the “effectiveness” of German armor vs British. Just to cherry pick some highlights, the Panzer IV was thought to be worth 1.5 Cromwells or .9 Shermans at 1500 yards. At 600 yards a Panther was worth 1.85 Cromwells or 1.55 Shermans. At 1000 yards a Tiger was worth .9 Sherman Fireflys! (the only model Sherman rated against Tiger).
        This was based on guns, armor, and actual performance; I don’t know what the specific formula was. But I found it interesting that right at the end, the British DID NOT see huge qualitative disparities between their tanks and German tanks. And actually considered the Sherman superior in some specific match ups. Their very worst match was a Cromwell vs a King Tiger, they felt it took 3.2 Cromwells to equal a King Tiger.

  6. Pingback: Sherman IC Firefly – faujibratsden

  7. Now you only need to look for a Sherman 76mm kit to make into “Oddball’s” ride from “Kelly’s Heroes”. Get some figs to paint up as Eastwood, Savalis, Sutherland, MacLoed, Rickles and the rest. Paint shells… 90mm fake barrels… fez’s with tassels… a few French wenches… could be fun! Some good diorama possibilities too.

    Strangely, that movie used the most correct (looking) vehicles of any WW2 movie before “A bridge too Far”… and many after that. Yes I know (now) that the Tiger I’s were VERY well disguised and operated T-34/85’s (though we speculated for years they were left over from transfers to Franco’s army). Still, it sure looked like the mighty 88 had come to life, tearing up the countryside. Remains one of my fave 4 of 5 star movies.

    [PS: why do I have to show a URL to post? I have no personal page anywhere, so had to use

    • atcDave says:

      Funny PS, I don’t know!
      But thanks for the comment. I love Kelly’s Heroes, fun movie. I haven’t done any Hollywood builds yet. I have one in mind to do someday, but its not that one. I have seen it done though, definitely an interesting subject.

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