If only the ballistics are desired - a .30/06IMP will deliver .300 H&H factory spec speeds in any M98 action.
; That's a simple re-chamber on any '06 or .308 even. Doing a .308 removes the necessity to pull the barrel- proper headspace for frieforming factory ammo can be maintained without setting the barrel back one turn.
; Indeed, Hornady's new light magnum ammo about duplicates original .300H&H factory ammo, and comes within 50fps of .300WSM.
; I hate belts when they aren't needed - and NO American ctgs. need a belt. Few years back, I chambered up an old 24" bl. .30/06 to .30/.338 without the belt. Excellent round, but only about 60fps ahead of my 26" barreled .30/06Imp. The .30/.338 duplicated my 24" .300Win mag as well. The max. efficient capacity of the .308 cal. is somewhere around 80gr. - about 3 gr. more than the '06IMP.
: My .375'06IMP has a 78/79gr. water capacity, depending on which '06 brass I use. Not far behind the 85gr. short mags, is it.
; I could never see burning an extra 15gr. or 20 of powder to get 100fps, but guys will do it and even an extra 50gr. of powder just to get 250fps. and from hunting positions they couldn't hit a moose or elk as 300yards let alone any further - Oh - am I ranting?
; If not building for nostalgic reasons, I'd go with a beltless .30/.338. You can use a .300 Win Mag reamer to cut the chamber. If a longer neck is desired, just hold the reamer back the appropriate amount and run the neck forward whatever extra you want with a neck throater from Dave at Pacific Tool and Gauge. Elementary stuff, this.