That's it. I'm carving a muzzle brake oout of a piece of sprue for a 1/76 Sherman Firefly, but I also have a Comet and a 17 pdr. towed gun, I'd like to know if the muzzle brake used by the 17 pdr is the same as the 77 mm HV's, you know, different length guns Thanks a lot in advance. Best regards.

José

http://tankarchives.blogspot.com/2016/08/17-pounder-britains-long-arm.html

If you click on the close-up photo in this article you'll get an excellent view of the 17lber muzzle brake. Compare that image to photos of the Comet and there doesn't seem to be a difference that anyone could see in 1/76. Perhaps there are slight differences in the vents on the sides of the brake (different factories?) with some being more rounded as opposed to squared, but in 1/76 that would be as close to invisible as is possible.

Looking at these 2 images of the Firefly and Comet at Bovington I would have to say that they were the same. No reason to be different: if it reduced the recoil of a 17pdr it would certainly reduce the recoil of the lower-velocity, lower-charge 77mm.