M4A1 Hull Front

[rexford]

Following up on previous message regarding M4A1 hull front vulnerability, outside of hull front is angled at 55° vertical and is at 45° to hull direction, for compound angle of 66°. Used 1/72 M4A1 model for measurements.

51mm flawed cast armor hit at 66° would resist like 3.5x slope effect x 51mm x .85, or 152mm good armor at 0°. This would be enough to deflect all 75L48 hits at any range, and 88L56 hits beyond close range.

The percentage of the upper hull front made up of armor with vertical and lateral slope is 19%, although shot scatter would tend to put most straight-on fire hits close to the center, which would decrease the percentage hitting the outside areas.

Question is whether highly angled outside areas make up for major weakspots within center area, which they may not.

[Bil Hardenberger]

Rexford you need a website. So you can put all this great information in one place... you have posted some great statistics, but as is now, they are scattered all over the forum. Talk to Matt, maybe he can help you out

Bil

[Doug Beman]

rexford, your dedication to facts is amazing. I bet you know how to use a slide rule (and that's a genuine compliment)

However, be wary of using model kits as measurement sources, especially very small-scale ones. I used to build quite a few, and subscribed to Fine Scale Modeler magazine for a while. Each issue had reviews of new model kits, and almost all were shown to have measurement errors approaching 5%.

DjB

[rexford]

Good point about model accuracy. Paid $17 apiece for 4 Tamiya 1/76 Tigers and the front lower hull width was REALLY out of scale.

Cross-checked the 1/72 M4A1 with Robert Livingston's scaled drawings from a real M4A1 that he found in front of a VFW.

Got to be aware of errors, though, thanks.