There are already high cap single stack 45 mags out there. Why not just use one of them?
I did a search on .45ACP High Cap Mags and the largest I could find in single stack was 10 rd. I would like to have 15 rds. Can you gives us any info that you know of? I have 10 CMC 1911 .45 mags for my 1911s and have considered moding a couple of those using the instructions in the sticky. 10 rd mags have 14 coils in the springs. Wolff has an extra capacity 1911 spring that has 18 coils.
.45 Cal Extented Magazine Springs
These extra long, extra coil magazine springs for Colt single stack .45 Caliber magazines have a total of 18 coils. Springs are intended for repair of custom magazines. Fitting is required. Note: Not intended to increase the capacity of standard 7 round magazine to 8 rounds.
As a retired engineer, I just like to tinker however if I can buy what I want thats usually the easy & cheapest route.