Difference between M5a1 Stuart and m3a1 Stuart

[Kai Stemm]

I note the slope on the right side of the turret but I have a few questions.
1. Is this the only difference
2. What is the point of the slope

 

[Greg Boeser]

You mean besides the difference of the boxy riveted hull of the M3 and the sloped, welded hull of the M5?

 

[GrauGeist]

The first two photos you posted are the M5, the third photo is the M3.

The M5 had the welded hull design of the M3A3, unlike the riveted hulls of the M3/M3A1, which included an increased mantlet with a degree of frontal slope but the M5 also had a raised engine deck. The turret was also expanded to allow the installation of the radio.
.

 

[Kai Stemm]

The first two photos you posted are the M5, the third photo is the M3.

The M5 had the welded hull design of the M3A3, unlike the riveted hulls of the M3/M3A1, which included an increased mantlet with a degree of frontal slope but the M5 also had a raised engine deck. The turret was also expanded to allow the installation of the radio.
.

Thanks