It is amazing the the pouch idea that many GI's came up with during WW11 of putting it on the butt stock of their M1 carbines was not followed up by someone who would make one to better fit the buttstock. After buying one and putting it on my buttstock, I found it was a tight fit for the magazines. I bought a 1950 version designed for the 30 round mags, added some elastic an now I can put 4 15 round mags in my modified pouch.