Help Identifying Magazines

[xbuilder9mm]

I am cleaning out my guns area and I came upon these three almost identical magazines. All three are made of steel. Two` out of the three have an inscription on the back side. one insc. reads reads thus AI with a small horizontal line at the top and bottom. The other reads either reads IS.
I asked about a year ago, and they were identified, at the time I wasn't ready to dispose of them, now I am and of course I lost the information.
I would really appreciate any info you could give me.
thanks

[bohoki]

30 carbine mags come one didnt even need to look at the pics

[mossy]

M1 carbine, 30 cal.

[Chaos47]

Look like M1 Carbine.

[mossy]

15 round capacity maybe. looks like that is a real 30 caliber assault clip.

[xxINKxx]

Inland mags to be exact.

[imarangemaster]

Hmmm, you have the mags, get a 30 Carbine to go with them. 110 JSP at 1970 fps and 900+ lbs ME at the muzzle. great little PDW or house gun (that's what I use) It will do at 100 yards what a 55 grain 223 from 16" barrel will do at 200. I've killed deer with one, and carried ione as an LEO trunk weapon for years.

Mine: