I finaly slugged my 1895GS today and to my suprise it was 456". That seemed tight so I did it two more times and came up with the same numbers. I been sizing my 405gr cast to 457 and having good results so I will stick with that till I start going through all the different jackets out there.

Slugged with a tight fitting, lubed, pure lead slug? Was the slug "bright" (showing contact) on both lands and grooves? Is the bore .450? How did you take the measurements and how do you "size a 405 cast to 457"? How's it been shooting?
Welcome to AR and I wish I could say I miss hunting in B.C.!

I used a pure lead slug and measured with a set of dial calipers. It showed good picture of lands and grooves on it. I did not measure lands I will have to do that yet. I use a lee size die to run my slugs throw, they been coming out of the mold 459".

I don't think dial calipers are precise enough to measure to the .000 accurately. You should use a micrometer if you want to really know what the bore is...Just my opinion. Shrps74