Im shooting a Remington 700 chambered for .308 with a 21" tube. I was wondering if i could get more out of my gun if i used a quicker burning powder? b/c im not be able to benefit from a slow burning one. Also could anyone give me some examples of good powders to push through a short barrel such as mine. Id like to load up some 130 grain Barnes X bullets which should make for a good flat shooting whitetail cartridge. Any help would be great. Thanks alot.

This comes up all the time.....going to a quicker burning powder only because you have a shorter barrel will not help.....all the powder that is going to burn (normally it all doesn't no matter how long the barrel) burns well before you reach minimum rifle barrel length of 16"...mostly in the first few inches.

I've done a fair bit of load work in a 20" 308 rifle, and a few 14" contender barrels. The fast powder myth just doesn't hold in reality.

I haven't tried 130's in the .308, but you should have no problem launching them around 3000 fps from your 21" tube. Check the Barnes manual for suitable powders. I know RL 15 and Varget work really well for 150-180 gr in the .308, but would imagine you'll want something a little bit faster for the lighter bullets.