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Howard Audsley

Origins of this question relate to efforts to hand load for a 308. Have modified my reloading process to include a couple new tricks.

First one it to obtain either a go or no go gauge for each caliber I'm loading for so I can tell where my chamber is relative to SAMMI specs. I measure the gauge with a case comparator, then measure the fire formed bass. For one rifle, the chamber is same as a no go gauge. Factory ammo has to stretch 5 to 6 thousands when fire forming.

For a 308 Win I'm loading for, it is only 1 to 2 thousands over the Go gauge. Factory brass in it has to stretch very little to fire form. Good to know.

The second step is to take all bullets I'm loading for and find the distance to the lands for each. When I attempted this with a 150 grain Hot Cor in the 308 Win I'm loading for, the shank of the bullet was hardly seated at all to get the ogive to the lands. My first thought was the rifle was screwed up (too tight chamber, too much free bore), but it is a factory Howa rifle, so how could that be? Then remembered the plight of "Joe" in Nathans reloading book who found the same thing.

Which brings me to my point. Can someone elaborate on what is going on in a 308 Win with the long/deep free bore?

In addition to Nathan's suggestion to seat it deep and let it jump, the other part about what is going on in a 308 chamber vs. others needs to be better known. If it is an idiosyncrasy unique to the 308 and a few others, then it ought to get more mention.

Lastly, if one does some research on this, with bullets like the 150 hot cor, I have found guys doing seating tests in reverse. Instead of seating out to near the lands and seating deeper, guys are seating bullet with base to the case neck shoulder region, and seating tests are to make it longer.

Nathan's discussion of this with "Joe" and a few other places in his reloading book is one of the very few places where you find info like this for the 308. It ought to be part of every discussion there is for 308. In every reloading manual.