Doing a pound cast

[fiver]

use some very light oil [3 in one or a slick vegetable oil] you just want enough to get the slug back out.

except for the diameter that's pretty typical for a 375 H&H.

 

[Ian]

WHEW, good news!

If the voids and crusty looking stuff is just hydrolocked lube a d the throat is in good shape, your pound cast is probably just fine for measuring. It doesnt have to be pretty, just functional enough to measure.

Compare what yoi have to the chamber drawing (and +tolerance specification) at saami dot org and I'll think you will find it's pretty close.

 

[fiver]

I pulled them into the other thread so he can reference them in that.

 

[35 Whelen]

I coated the bore, chamber and throat with breakfree. I will also give the bolt face a bit too next time. When I first tried to lift the bolt, I thought oh hell...that's super tight. Then a bit more and the camming effect kicked in and out it came no problem. I know that slug looks awful but there were enough flat shiny spots opposite each other to get a decent reading on the micrometer. I am going to do it again sans BLL next time. I want to be confident in my measurements...I think I am close. Thank you for the help guys...much appreciated by a novice at this sort of thing.