Re: Barrel contour 338Lapua
Chris Matthews might have an A-5 laying around that he could measure the width of the top of the forend on. You "might" have enough meat on the sides left after milling it out for the block, but you may have to use a 1.25" dia bbl to be comfortable with its rigidity.
I'm leaving .200" - .250" in each side of the aluminum block, not sure exactly what, but I might mill the sides down some when we get to it. it's .250" per side right now.
If you use a steel block, you could go even thinner per side, maybe .125" - .150" I'd guess?
Knowing the aluminum block had .250" thick sides, I added .5" to bbl dia. and looked for a forend that I felt was wide enough that I didn't have to mill down the block thinner, I still might mill it down some, as the top of the forend on this Master 1000 stock is still kind of thin for my liking with that much removed.
I think the A-4 and A-5 would have definitely had to of used a thinner block, I did look at using the A-5, as it had just came out. If I remember, McMillan told me 1.25" with out a block is what the A-4 could be inletted for. It would have too close with the aluminum block I figured, so I found a stock with a wider forend to work with.
My next barrel will be 1.25" dia so I can use the A-5 with no problems.