looking for another upper used for only target shooting at 200yds and up. can anyone tell me the pros & cons of either size barrel. will be using a scope & shooting from a bench only. thanks for any input

24 inch should give additional velocity, while the 20 inch should be more accurate (theoretically).  If you are shooting over 600 yds, get the longer barrel, you'll need the velocity to keep the heavy bullets supersonic with reasonable loads.

HTH....SRM

Hate to disagree but any barrel is theoretically as accurate as any other barrel theoretically beyond a minimum length and out to some way too long lenght. Within these extremes (say a few inches to many feet long), in theory, a barrel can be as accurate as the next. In practice, off the bench, longer barrels work better.

If you're just target shooting you'll want the 24" barrel as it reduces mother nature's influence on the bullet before it strikes target.

The extra 4" will add some velocity to the round meaning that the time between the barrel and the target is reduced. That means the forces of nature - wind drift and gravity have less time to act on your bullet to alter it's course.

Benchrest shooters have big long thick barrels as they heat up slower, vibrate less, and increase bullet velocity.

Scoped, from a benchrest, 16", 20", 24" should be equally accurate, assuming they're just different lengths from the same barrelmaker, with the same cut rifling, etc. Theoretically, a 10" T/C barrel can be every bit as accurate as a long rifle barrel, if the shooter does his part.

With iron sights the 24" has the advantage of a longer sight radius. Doesn't help the barrel be more accurate but it helps the shooter aim more accurately.

I agree about the additional velocity from a longer barrel reducing the effects of wind drift and gravity.

Quoted: Hate to disagree but any barrel is theoretically as accurate as any other barrel .......VIBRATE LESS, and increase bullet velocity.

I added the caps.  The reason I said shorter barrels are supposedly more accurate is based on the barrel vibration.  As I understand it, a bullet leaving the muzzle at >100,000 rpm will cause the barrel (especially the muzzle) to vibrate/whip, kinda like an unrestrained fire hose on full blast.  A longer barrel=a longer moment arm and increased barrel vibration vs. a shorter barrel.  Are my physics wrong?

In the words of Dennis Miller, "of course, that's just my opinion, I could be wrong."

SRM