Does anybody know details regarding a Marlin 1895 square bolt in .40-82? Mine was built in 1896 and is in perfect mechanical shape. It was reblued sometime in the past so its value as a collectible is reduced. I'm planning on hunting deer in North Dakota next fall, but I'm not sure what my bore diamter is; .408 or .410?

I've found several load data on the internet, but anyone know any loads I can start with? I would appreciate any help!

Montana bullet works has several cast bullets that should work.

Bill Roberts Homer Alaska

Probably .406 or .408.
Slug it yourself to make sure.

Order the back issue August 1999 No.200 issue of HANDLOADER magazine it has an article by Mike Venturino entitled .40-82 Revisited.
The article describes Mr. Venturino problem getting a vintage Winchester Model 1886 shooting.
The article has load recipes for this cartridge.

COTW says that the 40-82 Winchester was typically chambered in rifles that had groove diameter of .408", but the bullets in the original loads were .406" diameter, 260-grain.
Sometimes COTW gets it right. Trust but verify.

They say the Winchester factory loads were 260-grain at 1490 fps.

I would slug the bore. All three of my '86s shoot .410 bullets very well. The .408 and .406s tumble at any velocity. The above cited article by Venturino covers that. However, we are talking 86s here not the Marlin, so slug the bore. Dr, C PS I would keep it a .40-82. Quite powerful for most purposes. Dr.C