Hello all I'm sure this has been asked on here before but I wasn't able to find what I was looking for.my question is what is the optimal barrel length for 308 win I have a remington 700 sps tatical with 20 inch barrel and I can't get the fps I would like to get out of it im getting just over 2700fps with 152 hh and mid 2600 with 168 amaxs I've been thanking of having it rebarreled but this rifle shoots .350 with both loads and before I just chunk a good barrel with less than 500 rounds on it I've been looking at just buying another rifle with longer barrel either 22 or 24 inchs.so my question is which barrel length would be optimal for 308 and also is these velocity good or just average for a 20 inch barrel and what should I try to get more fps out of it.by the way both loads are 45.5 grains of varget in lupua brass 2x and federal 210m.with the long chamber/throat in this rifle I'm around loading to max box length because the bullets aren't hardly in the case any were near the lands.thanks in advance