Heiser three cell

[Leadeye]

I ask this question on various boards that I visit and am still searching for an answer. This is a 3 cell ammo pouch from Heiser leather, made after 1928 based on the snaps. The magazines for scale are for a Colt 1902, Colt 1903 Hammerless and a Colt 1911. Any guesses or info would be welcome, so thanks in advance.

 

[EZ-E]

If they're bigger than 1911, then more than likely a small rifle cartridge. My guess is M1 carbine?

 

[Leadeye]

If they're bigger than 1911, then more than likely a small rifle cartridge. My guess is M1 carbine?

A good guess thanks! The pouches are as thick as a 1911 mag, taller and half again as wide.