Gaday from Australia , I have a 7mmBB with 1 in 8 Twist and it works perfect and groups well at all distances. For Rams with 175 Finns and also 175 Sierra Match King. I have been using 145 Finns for the others.
What I did find, when doing some testing last week in windy conditions using flags to the first 100 Metres. Shooting groups firstly at 100, then at 200 and 400m to 420m Approx. With a selection of projectiles from Sierra -100VM, 130HPBT, 150 HPBT, 168HPBT & 175 HPBT, / Finn 125, 145 & 175HPBT made by Anthony Finns From Australia, and Hornady 100 HP,120HP 139 SST & 162 A-Max. What I did discover was in the wind, that the heaver projectiles all grouped better than the very light ones up to150 grains for Chicken,Pigs and Turkeys. The Finn's in 145 grouped the best of the ones up to 150 grains, then the 139 SST. Of the heavies the 175 Finns and Seirra's grouped the best with very little between them at the 300 and 400 , followed by the 168 then the 162 A-Max, My loads for the 162 to 175 varied form 32.5 to 29.5 of ADI 2208 / hodgeden , and 33 to 30.5 of BM2 and 2206H to get the best groups at 100 I don't have a chronegraph so I am not shore how quick they were going. I used the method Dan Theodore told me with a string at same point of aim increasing the load till they stop climbing or the primers start to show then did 3 shot groups and either stayed at those loads or came back a little to get the best groups, any of the projectiles used would be fine in good conditions. But I liked the 139SST and 145 Finns out to turkey's, the thing I liked about the Finns was that they are the same dimensions as the 175 Ram kings and changing the redding comp seater was not required. The groups with the 168 & 175HPBT Sierra and the 175 Finns there was very little difference with the 175 Sierra's shooting a little flatter and slightly better group average of the three Five shot groups shot by each enen though the Finns had the best groupat 400but nothing in it really.
I recken that the Comp seaters should have a Caliber sized hole bush in them as well. Then seating the projectiles they would be all just touching the rifling, no matter what the length or style of projectile or you wind it down like now to amount required off the Lands, it would make life easy when set up, and testing at the range. Besides the possible slight mark on the projectile there must be other reasons for not having that set up but with my lack of experience I don't know what it would be .
To Finish "The man" to talk to on here, that helped me, with what to do when I was finding a load and combination was Dan Theodore,everything he told me was spot on, he is a very knowledgable man and very helpful. Regards Phill
