I also usually throat rifles with a parallel throat which is .0005" over nominal bullet diameter (ie. a 30 caliber wil get a .3085 throat). This generally works out well but not always. Upon occasion, one may get some bullets which are a bit large and this can be a problem.
The primary requirement for the rifle's throat is that it be concentric. The 1.5 degree angle in is SOP nowdays though some still prefer the 3 degree and one reamer maker thinks a 3/4 degree might be better. Who knows?
I have shot some very accurate rifles which were chambered with the typical long, tapered, European style of throat. Shultz and Larsen target rifle barrels were chambered this way and worked real well.
If the throat is concentric and of .0005" over bullet diameter, the amount of freebore (distance to the lands)does not seem to be real critical in the world of hunting accuracy.
I still favor the throat as described by Malm but the longer I do this, the less certain I am that anything is certain.
The most accurate hunting rifle I have in my rack has a long tapered throat and the bullet is nowhere near the lands. The most accurate target rifle has a parallel throat and shoots best with the bullets well into the lands. GD
