Fellas, I was looking at a Springfield sporter the other day and got to thinking I could buy the thing, send it to Jesse Ocumpaugh at JES reboring and have him rebore it, but I see his specs are a .402 land and .412 groove. My questions are, would this be accurate with a .411 jacketed bullet, and how thick does the outside contour of the barrel at the muzzle need to be to give adequate barrel strength and stiffness?

I thought mine was built on a Douglas #3 which is .625" if it is a #4 then .65"

I've found that my 400 can't tell the difference in .410 or .411 dia bullets.

Besides this isn't a Benchrest chambering.

I was told by the late Jim Dubell of Clearwater Reboring that a barrel wall thickness of .100" at the muzzle was the minimum allowable, so your .412" caliber barrel would require a muzzle diameter of .612".

I just measured a 1903 Springfield with a military barrel on it, it mic's at .619" at the muzzle
Just behind the front sight it is .645"
that should work for a 400 Whelen.
Like Ramrods rifle mine doesn't know the difference between .410" .411" bullets, same group sizes.
If yours turns out at .412" I can't imagine a problem.

I spoke with JES about reboring a Springfield about a year ago and he said it could be done. I was all ready to do it until I had something pop up that took my gun funds. Since then I have bought a 375 Ruger and dropped the idea of the 400 Whelen.
The Springfield just sits in the closet waiting for something to come along.

JES did my 375 Whelen and at the time said he liked to have at least .200 over groove diameter for a rebore. A .412 groove diameter would then require a .612 OD at the muzzle.

No worries on the .411 bullets in a .412 barrel. Mine is a .411 groove diameter and shoots the Hornady .410 bullets just fine. In fact the Swift A Frame bullets measure .4095 and they shoot great.

Please forgive me. I have no intention of hijacking this thread but,
I was wondering if someone had this info.
I always wanted a rifle that could use pistol bullets for volume plinking.
I just realized the .400 could use 41 mag bullets.
Considering I would buy just a standard m70 from one of the LGS's and have it rebored.
Would any one know the muzzle diameter of say a M70 30-06?
If sufficient it would be an easy and inexpensive purchase to make a .400 whelen.

I just went out to the garage and dug out the take off barrel from my model 70 that I used to build my 400. The muzzle diameter is .595. That's too skinny and honestly even though a .611 barrel would work for a 400 Whelen, that would make an awfully light big bore. I used a Shilen barrel. It is 24 inches and .675 at the muzzle. It is a comfortable shooting rifle. Just heavy enough to control the recoil and still light enough to be comfortable to carry.

Pistol bullets do a number on waterjugs. I've used them on TX Jackalopes.

The take off was a 06?
Thanks.
Yes that seems to small from what was said was desirable.

Sorry about that. Yes, it was an 06.

I just measured a Ruger M77 tang safety 30/06 and a Win M70 30/06 at the muzzle. Both were right around .595".

Thanks gentlemen.
would cutting these barrels back to around 22 inches give a .61-.62" muzzle diameter?

Both that I measured were 22"

I don't have a M70 06. But my MKX 06 barrel is closer to .55 at 24" it takes 3.75" to get to .61
So that works out to about .016"/inch using the same taper then sorter the m70 by an inch is .595+.016=.611 or .627 if you take off 2"

My 400 measures .75 at the muzzle,@ 23". It is slightly nose heavy now but when scoped and a full magazine it will be perfect.I'm guessing it will weigh in at 9lbs ready to go which is fine with me.

Thanks Gentlemen....