Load for G98/40

Hi all
I have post this on K98k forum but dont get any answers.

I got my hands on a 42 German G98/40 all matching.
WaA 56 serial 3169 e.

Bore is nice and with Sharp lands and nice looking crown. no visible troaterosion.
So I expect the riffle to shoot well!! But it dit not.

I have tried different ammo. From original German WW2 surplus to S&B and Prvi. and different handloads.

I shoot at 200 m and hit the taget (normal 10 ring) all over (and some outside taget) with all ammo.

Then I slug the rifflebore on the 98/40 and three om my well shooting K98K.

And this is what it shows with micrometer:

G98/40 :
Owerall: 0.3258 (full lengt to find min. dia.)
6 Inch from Mussel 0.3267.
Over land: 0.3145

Three K98k's Overall:
6 inch from Mussel 0.3232 too 03234
over land: avarage: 0.3115

So, is it possible that the Hungarian have cheated a little with the barrel on this riffle ? is it made by reaming the camber to 7,92x57 from a 35M 8x56R barrel or simply made of raw barrel material in stock for 8X56 R?
(same factory made the Hungaraian 35M in 8X56R at the same time)

At the pipe over the chamber is stamp 7,92 (normal K98k style)
But I can say for sure it have never been that.

The max Neck size for 8x56R is .362 and it is about what i is in this G98/40
8x57 Js should be max .357.
(so also indicate conversion from 8X56R)

The reason I ask is that Prvi make 196 grain FMJ bullets for 8x56R in 0.327
I have made a 0.327 dummy bullet and put it in a fullsized case with expanded Neck. It will chamber fine with no resistans at all. Then I have expand the caseneck a little more until the bullet drop into the case with no resistans. Emty case still chamber without resistans.
(this case will not chamber in any of my K98k)

But it mean that I have to made up a Hybrid Cartridge. Hmm.
For safty reason I plan to use only necksized cases so they not accidently chamber in other rifles.

If any other have heart of same problem with this rifles I will be happy to hear.

Anything from you experts?

Best regard

JSNE

I have over 300 1898 + rifles chambered in 8x57mm . The groove size runs any where from .322 to .327 . All my Austo/ Hung rifles run large . With the larger grooves a flat base bullet will shoot much better that a boat tail . Will also can get better results by changing powder burn rates and muzzle velocities . Yes you can use the larger dia bullet , just work up your load . You will pick up some pressure and velocity with a .001 or .002 + jacketed bullet . If the loaded round will chamber with no resistance , you are good to go . The " case needing to expand to release the bullet " is not true . My tight neck bench rest target rifles have zero neck clearance . You can pull a bullet out by hand and the case neck does not expand to " release " it .