The initial run of 'Jumbo' Shermans (the heavily armoured ones, not the Italeri boxing with the wrong name)

were all fitted with a 75mm main gun, as found on many Shermans, as it had a good HE shell, for it's intended bunker-busting & column leading role.

SOME were retro-fitted with the 76MM gun & mantlet to give it a much better Anti-Tank capability, but the trade-off was that the 76mm had limited HE shell availability.

I don't recall seeing any with a muzzle break fitted, and/or the threaded end-cap but someone will know better.

There are photos of both. Just didn't know the ratio. Which was more common if so.

The Jumbos as built came with the 75mm gun. Some were rebuilt/rearmed in early 1945 with the 76mm gun. I have yet to come across a photos of the 76mm Jumbos with a muzzle brake. It was not so much a ratio, but rather whether or not the Jumbo survived to 1945 and went in for the upgun rearm.

Not a muzzle brake

I have yet to come across a photo of a Jumbo with a muzzle brake. They were re armed at depots in Europe, and likely the stocks of 76mm guns were earlier build ones kept as spares for replacing worn out guns.

Again...NO muzzle brake. Threaded barrel with end cap(washer).

Are you asking or saying "no muzzle brake"?  I am at work and do not have access to my library at the moment. So can not say definitively if those upgunned to 76mm and photographed had either the end cap or the non threaded barrel.

I know they didn't have the muzzle brake but many did have the end cap. Just wondering roughly how many

I think MountnRide is referring to the M1 A2 76MM gun with the thread protector.  There are some photos here http://the.shadock.free.fr/sherman_minutia/m4a3e4/m4a3e4.html. 

Here's a photo for discussion only:

That's all I can offer.  I don't have enough references to determine if any Jumbo's had the thread protector.

I did a quick google search. Most the images in my books that have the Jumbo were found there. Looking at the ones I found on the image earch shows both types of 76mm guns being used, but the smooth end and not the capped end were more prevelant in photos.

You da man Stik!

Have tablet. Will travel. ;-)

I glanced though some of my Sherman books and only found a few photos- but all were the plain barrel without the end cap.

 Apparently a late war addition. 

The M-1A1 76mm main-gun w/muzzle brake was installed on Cobra King in March 1945 (a year after the tank broke through Bastogne) at the direction of Lt. Gen. George S. Patton Jr.

To my knowledge it is currently at the U.S. Army Museum in Washington, D.C. after being restored to its original configuration.

disastermaster

 Apparently a late war addition. 

The M-1A1 76mm main-gun w/muzzle brake was installed on Cobra King in March 1945 (a year after the tank broke through Bastogne) at the direction of Lt. Gen. George S. Patton Jr.

To my knowledge it is currently at the U.S. Army Museum in Washington, D.C. after being restored to its original configuration.

Here is Cobra King in "original" configuration, shortly after entering Bastogne. With the original 75mm at that point

Here is an upgunned Jumbo from 4th Armored division with the smooth barrel tip

and here is one from 3rd Armored Division with the threaded/capped muzzle

Disastermaster: Your pic is of Cobra King before it got its full restoration.  It was brought back to Ft Knox where it got its paint stripped and all its parts re-done.  You can read about it here:

http://www.armorfortheages.com/NACM/NACMmain/Projects/CobraKingProject/CobraKingProjectPage.htm

www.armorfortheages.com/.../CKProjectPage50.htm

Currently, it resides at Ft Benning with T48 track, the correct markings for Cobra King and a 75mm gun.  The pic you posted was before a historical restore so the muzzle is suspect (likely added by the restorers who prepared it as the gate guardian in Germany)

Where is ol' Shermanfreak when you need him?

T26 that is great to see such a historical tank being in such condition and placed at Benning. I hope they can find another run of proper tracks for the right side to finish the job.

They have plenty of spares at Benning.  Here's my hand on a piece of history:

i45.photobucket.com/.../100_3325_zps860b7a2c.jpg

Outside, the motor pool guys had some Marines who were awaiting a training course to begin, working on installing some track on an M4 (105).  Nothing like hands on training!

i45.photobucket.com/.../100_3302_zps4d11b231.jpg

i45.photobucket.com/.../100_3303_zpscb366487.jpg

I wonder if they knew the history that they were helping to preserve...

I would think so.  They were all there for a tank mechanics course.  The motor pool has hundreds of artifact vehicles and arty pieces.  The guys who run the motor pool are ex-tank mechanics and I'm sure they were giving the context of the vehicles to the Marines.  The photos actually show them battling w/the idler adjustment I believe.  The head honcho of the motor pool, Len Dyer, is the one with the bluejeans.  His assignment for the guys is to loosen the idler w/o any power tools.  They needed to get some huge torque using only simple tools -- an exercise in problem solving.

Okay, who stole my chickenwire....

T26E4

Disastermaster: Your pic is of Cobra King before it got its full restoration.  It was brought back to Ft Knox where it got its paint stripped and all its parts re-done.  You can read about it here:

http://www.armorfortheages.com/NACM/NACMmain/Projects/CobraKingProject/CobraKingProjectPage.htm

www.armorfortheages.com/.../CKProjectPage50.htm

Currently, it resides at Ft Benning with T48 track, the correct markings for Cobra King and a 75mm gun.  The pic you posted was before a historical restore so the muzzle is suspect (likely added by the restorers who prepared it as the gate guardian in Germany)

Hey, some great info there, thanks.......

......but if Patton said so - wouldn't that make it so? (the moment in time scenario)

If you read the restoration blog, you'll see that Cobra King's original 75mm was later swapped out for a 76mm upgrade.  But the restoration's goal was to depict Cobra King during the Battle of Bulge timeframe so they purposely restored it to an earlier configuration.

  I read it.

 I was only trying to illustrate that the configuration did exist at one time and wasn't really concentrating on that particular vehicle.

 Below is Commander Creighton W. Abrams Tank (not a jumbo) of the 37th regiment 4th Armored Division January 1945 Bastogne and a testament to the use of the muzzle brake.

 Next, a HVSS version..

 In 1944 the higher-velocity 76mm M1A1 gun was introduced that gave the Sherman armor-piercing firepower comparable to the Soviet 85mm ZiS-S53 gun.

 The HVSS suspension modifications were made to address the greater weight of the larger turret and 76mm gun, and to generally improve the ride of the tank. The hull was welded and the armor slightly thickened (in contrast to the cast hull of the M4A1 above) bringing the total weight to 33 tonnes.

Next is this seriously handsome beast which isn't in the assault tank configuration (jumbo) either, but another example of the Muzzle brake.

 I'm far from being a know-it-all here and I know these are museum pieces. I put this info up as an aide to the newer and possibly less informed members on the forum. 

Guys.....

Isn't it funny how a thread starts and then bounces all over?