Re: Bedding Manners Mini Chassis?
DO NOT TIG weld the lug area of the stock!
The manner's chassis is a permanent addition to the composite stock it resides in. You cannot remove it. It is both epoxied and screwed to the outer shell.
If you go blazing with a TIG you will ruin the surrounding area of the composite.
IF your using a lug that is too big for the existing lug well, maybe consider using a different lug if the thing hasn't already been put together (the barreled action)
OR
Get a 1/4 3F high helix endmill and just enlarge the opening to accomidate the new lug. If your smith sets up the stock properly and rigidly, then this is a very, very simple operation.
You can finish it with an 1/8" EM if you go really carefully. This will avoid having to "dog bone" the corners to provide edge clearance on the lug.
This is how I do it:
Lay the receiver in the chassis. With the stock fixtured indicate off the face of the receiver. I stick a machinist parallel against that face to give me a wide/ground edge to run my indicator off of.
Run your indicator off the edge and adjust the fixture until you see zero movement on the needle. This qualifies that face and the stock at the same time. You want to go off the action since this is what the stock is supposed to be fitted to.
Once you have this you make an assumption. Surprisingly enough, most round actions are pretty darn consistent across the outside diameter. About the only time they get weird is when they are heavily polished (like on a dedicated blinged out Bench rig).
Even factory M700's are pretty darn good.
So, you can do this one of two ways. You could run your indicator along the top of the receiver's front ring to ensure your parallel or you could just go right off a flat surface on the bedding block. In either case your making the assumption that the "V" chassis is parallel. I personally would go off the receiver, but whatever.
Now that you have this, just skim the surface that the lug purchases against. Zero to ten thousanths isn't going to hurt a thing. It just means the action sits ever so slightly towards the rear. The action screw holes are blown out so oversize that it won't matter.
-Besides, it's not like manufacturers are holding guard screw locations to a true position of .001" anyway. (that would mean that in all 3 axis's the holes within .0003" of perfect location)
Just machine it nice and clean and move on with your life. It's not rocket science.
Pointers. A 3F high helix EM will leave a nice finish. Don't go blazing at high rpm as it will likely squeal like a pig. (tool chatter). Run it slow. Even the best fixturing when working on stocks invites chatter because you can't "put the mojo to it" like when holding a block of steel in a Kurt vice. You'd crush the stock and ruin it if you did.
Leather on the jaw surfaces helps quite a bit with stock work holding as it spreads the load a bit and conforms better to the outer shell.
Good luck and hope this helps.
C.
