Less than 100 yards? Why not consider a handgun caliber like .44 Mag or .357 Mag? One of the Ruger carbines in .44 Mag or a lever gun in either caliber would be a great little gun.
I'm with BBQLS1 on the suggestions. Light to carry and easy to handle rifles chambered in .44 Mag and .30-30, as well as some similar rounds, are very effective inside of 100 yards. Pistols are fun too, but you must practice to become proficient.
I'll assume you are shooting the .270 from a bolt gun. .25-06 will require a similar sized rifle and kick about the same. It is actually a necked-down .270, which is a necked-down .30-06. By going to a short action, you will save some length and weight in a similar bolt gun. .243, 7mm-08, and .308 are progressively necked versions of a shortened .30-06 shell. With the smaller powder capacity, you get less recoil. With a bullet weight up to 165 grains, the .308 will match the .30-06 in all ballistic properties. The 7mm-08 very closely matches the performance of the .270. The .243 is a softer choice that can be quite effective with reasonable shot placement. The .243 can also double as a varmint round. Anything smaller than a .243 will require pinpoint accuracy and leaves no margin of error.
Another choice would be to get one of the single shot rifles legal for Primitive Weapon Season. Very effective inside 100 yards and covers the extended season.
My personal choice is to buy 'em all. You'll eventually settle on a couple as your favorites. The rest can hang on the wall and really spruce up the look of that den!