I need a scope for 24" barreled AR upper.  At this point in time Leoupold or Burris or Swarvosky is out of the question.  What is you favorite of the cheaper brands?  BSA?  I want a 40 to 50mm with an adjustable objective.  Any help would be appreciated.

I have always had better luck with the Bushnell. There is a good Korean made 4x12x40 with an adjustable objective for $49.95 from Natchez Shooting Supply. Most cheap scopes are made in China now. The last of the Korean Bushnells are pretty good for a cheap scope.

Get a Bushnell instead of a Tasco, since they went bankrupt. You might alos look into BSA. A friend has one and said it was an ok scope for the money..

Choices:

1) Bushnell
2) Tasco
3) Same money for a GOOD scope.

I think this is a no-brainer.

What's your definition of a cheap scope?  Under $200?

My recommendations, in order of price:

Weaver V9 3-9x  $150ish
Bushnell Elite 3000 (closeout) $150-300
Sightron $150-350
Redfield $150-400
Swift $100-250
Simmons Aetec $130-200

I will never again throw money away on a cheap Chinese scope like the BSA's, Tascos, or entry-level Bushnells.  I have wasted too much time and ammo trying to get them sighted (or re-sighted) in.  I'm sick of not being able to focus on the reticle and the target simultaneously.

You say you want an adjustable objective, but many of the cheap scopes are going to exhibit parallax problems even with an AO.  And on any power up to about 16, a 50mm objective is just extra weight.  Especially on a cheap scope, a bigger objective doesn't necessarily mean a better image.  It might be brighter but it won't be better.

I strongly recommend getting a lower powered model of a good brand.  These will often have better resolution than a higher magnification Chinese scope.  

I would recommend a Nikon Buckmaster 3-9x40.  Excellent scope for the money.  They usually run just under 200.00.  Very clear optics.