M-1 carbines can use 15 or 30 round mags. Your carbine will be able to use the 30 round magazine. The thing to know is it's a good idea to get the M-2 magazine catch, which has an extra "fingerlike" projection to catch the extra tab that is on the rear of the left side of the mag. This will help hold up the extra weight of the 30 rounds. Lack of this catch will not prohibit the use of 30 rnd. mags, but you may find the mag catches on back become distorted.
Also, on some 30 rounders, the follower is shaped to catch the bolt back when it's empty, so don't be surprised if that happens; it's normal. The G.I. 30's have this, the aftermarkets will vary. Some will have the 15 round follower with the ramp the bolt pushes down.