Any Experience w/20" 6.8 SPC

[knc1105]

I have a Bushmaster 6.8 SPC that I bought Pre-OBama. it is a 16" 1-10 twist and it likes the heavier 115 gr bullets. With the 115 Match King Boran Nitride coated and H-322 it is very accurate but chronographed 2,555 fps not a real flat shooter. I had some old 100 gr Nosler Solid Base bullets I had Boran coated and tried to work up a load for them and found 1 and only 1. I ordered and it shipped last week a 20" 1-11 twist heavy barrel. Any load data or experience with a 20" barrel would be appreciated. I am thinking I should get an extra 100 fps or so with the longer barrel if the powder is right. Which should put a 100 gr bullet at about 2,800 fps which is close to a .243 Winchester and for a AR that would make me very happy. I was originally going to swap the barrel but now I think I'll get a upper reciever and Yankee Hill forend and share the bolt. That won't be that much and I have extra rings and scopes on the shelf. Any help would be appreciated. Ken