V-Block included angle?

[Jonathan Zimmerman]

So my question is about v-block angles. Most aluminum and fiberglass stocks have a v-block configuration to hold the action (similar to a machinist v-block). I am making my own stock for fun. Why do you suppose the normal v-block stocks have such large included angles to support the action as opposed to 90 degrees (like one made for machining)? I know other angles have been used for v-blocks but that is the most common. Any ideas? Thanks

 

[missed]

I think it's a matter of deflection. If you have a 90 degree block and it is no wider than the action how much deflection do you wind up with in the block when the action gets torqued? I have built a few blocks, I have done them at 90 and 60. I didn't like how much under the action was not really supported. I liked the 60 better, but when I have cut them I just roughed it with my Iscar ripper mill with the tear drop inserts and finished with the face mill with similar inserts which left me with a .125" radius in the bottom.

The Badger mini chassis have a double angle cut with large radius in the bottom. There is the bottom radius, one angle at the lower half and a steeper angle at the upper half. It surrounds the action more than the single angle cuts.

I have been cutting the 60 degree v blocks and have been happy with them. I don't have any quantitive data to prove the deflection or change in accuracy. But I do know I can swap stocks with the 60 degree block and the Badger and they shoot the same (Salvage actions). There is a Manners T4A with the Badger mini chassis waiting for the Mausingfield action.

 

[Gundoktr]

Those H-S V-blocks are not a true V-block. They have a small ridge on each side to which the action rests. You can see it in the wear marks on the receiver