I will be loading 180g Accubonds for my 300 wsm with a 23" barrell. The nosler reloading book says they did there tests with a 26" barrel. I dont have a chrono so I am just wondering if someone might know approx. how much I will lose.

Prob about 40fps-ish an inch loss but that depends a little on powder burn rate.

honestly not enough to notice just my 2 cents. in some cases ive seen a shorter barrel hit a higher velocity then a longer barrel with the same load velocity also has alot to do with many other variables that are more prominant thatn barrel length like bullet constricity in the bore, twist rates and powder burn rates. with new technologies and better proppellents these days worrying about barrel length is a bit old old fashioned unless we are talking barrel lengths under 20 inches. I honestly wouldnt worry about it

Like DB48 said you lose about 30 or 40 fps for every inch taken from a longer barrel. This rule isnt written in stone but it applies to almost all centerfire calibers

125-150 FPS loss.

Actually, I disagree. With everthing else being so equal, bbl. length will be the only variable. It still will hingle on the amount of powder, burning rate and how many inches of bbl. the charge has to ignite fully and build up pressure.

Do you think the deer knows the difference of 100 fps?? My point was there is very little terminal performance difference between a accubond moving 2,960 fps and 2,860 fps... atleast not enough for anyone to really tell realistically speaking. Once again IMO I wouldnt worry about it.