I realize it would be a WAG but given the powder charge, bullet weight, and bbl length, I would expect to be able to get a decent guess within 200 fps.

I usually have been reasonably close to the expected trajectories by simply working up to a load thats at or slightly above the powder charge listed. With this length barrel ( 1"shorter than a chronographed ), and the .2gr charge increase, I expected to be closer. When comparing my actual trajectory it's closer to 400 or more fps slower.

Truthfully this is the first time I actually wanted to chrony a load to prove what I'm seeing. Most times If I can only go as far as I can without pressure signs, and accuracy is good, I don't notice the tradjectory being so far off. Given the trajectory, and load info, one can guess pretty closely what the velocity is by backtracking the ballistics tables.

I suppose this could be an excuse to buy one. Nate

Nate, I'm not going to guess at your velocity, but I doubt the loss you seem to think you have. Trajectories are not linear in their progression, and I suspect if you were 2.5" high at 100 yards you would be pretty much in line with your expected 4" drop at 200 yards. Another issue is BC. I wouldn't know what the BC is for the Woodleigh bullet, but I note you're using the Sierra Ballistics calculator. You got the right BC pluged in?

I checked B.C. and S.D. on the Woodleigh webpage. I also plugged numbers into pointblank to cross check Sierra, just to see if it changed much.

Maybe it is really closer than it seems. I had a load for the 7mm RM I was planning on using. Then had some scope / mounting problems so figured I'd use the .338. Not trading down really but the flat tradjectory sure isn't there.