I'm not positive, but a 340 Easton/Beman size should be a little stiffer than a CE 300. The sizes overlap somewhat. I think a CE 300 covers the upper part of an Easton 400 and lower part of the 340 spine range. The 400 CE would cover the Easton 340 range and probably some of the 300 as well. You could check at Easton's web site or on Bowjackson.com.