The dimensions for 14.5x114mm are publicly available and you can find them in a couple of places.
Here are most of the dimensions:
View attachment 23601
How do you plan on making yours by the way? I chose the easiest method and 3D printed mine, but it gets pretty pricey.
https://www.shapeways.com/product/V6DKJH6GW/14-5x114-apfsds-t-x-x
No problemo.
A loaded SRS mag would be a really cool. Actually, do you know where I could find the dimensions for one?
Tell me how your print goes too! I'm assuming it's an FFF printer you're going to be using?