223 magazine lenght

I am going to build a 7mmTCU for HP Rifle Silhouette and I was wondering what the max LOA is for a cartridge in a .223 blind magazine? I havent decided on a Stevens or a Savage action yet. Probably will be a Stevens action since the whole gun is cheaper than just the action.

I am looking to load to a LOA of 2.79 and would like to be able to load in the magazine if possible.

Thanks!

measured 2 of mine
first one 2.415
second one 2.420

Do a search, seems like sharpshooter posted those measurement's at one time.