UNFAN1: for those situations in which you wish you had a scope but did not you will probably want to find a big tree to bang your head against. Even if your shots may be within 75 yds, as markc said, it gives you a greater advantage and allows a better shot. In the event that you see the trophy, or harvest of your dreams, all the way out to 150 yds, you would benefit from a scope for that shot.
I have found, as most of my shots will be within 150 yds, that a low range variable of fixed power scope is preferable. I just purchased a Bushnell 1.5-4.5 Dawn-Dusk scope to replace an older junk scope that went belly up and I am still amazed and quite pleased with the amount of light gathering and clarity even at just the 1.5 power out to about 150 yds.
Bushnell is available. Weaver still makes the 2.5, 4x and 6x fixed powers. Leupold and others make a number of fixed power or shotgun scopes, even pistol scopes with close in eye relief. For a powerful caliber or hard kicking rifle, there are many shotgun scopes that might serve you very well indeed. But, I'll tell ya buddy, I like that Bushnell I just picked up - I think it's a darn fine scope. I'm off to the range, hopefully, tonight before the sun sets to sight her in and I think I'm gonna have a good time doin' it, too. Just my 2 cents worth but, as always, I hope this helps. Mikey.