In Frank de Haas's book he states that the barrel should be tightened to the ring but not touch the face of the receiver itself. I've only chambered a couple of 98s and both i set up so the contact was about the same at both surfaces. They seem to shoot fine. I'm getting ready to do two more for myself and wouldn't mind hearing thoughts on this matter.
Does it really matter?
One is an FN commercial action, one a modern 98 double square bridge.

I've never rebarreled one but, used to know a guy that had done a few on 98 actions. He had a really nice .284 Win. on an Argentine 1909. He had used the hinged floorplate and made a really nice latch for it.

Kuhnhausen states that the inner receiver ring is the primary torque surface and the front of the receiver is the secondary torque surface.

I read this to state that if the barrel is in contact with both surfaces when tightened, it's okay. I have gotten away with this for 10 builds or so. YMMV.

I don't know if it really matters...but having rebarreled dozens I can comfortably say that original Mausers from the previous century did seat on the inner abutment, and the outer shoulder interference was snug enough to prevent the entry of water. So that is how I fit the new bbls. Also if you fool around with a depth mike from the front outer shoulder to the inner abutment, C ring, you will discover the outer shoulder is not a precision datum point, it is quite normal to see several thou variation in depth. You will never go wrong if you stick with Mauser's original intent.

Steve Acker in his book, The Gunsmith Machinist, describes barreling a 98 as flintlocke does

We, in four shops, used to remove barrels from old, as in issued 98s. They usually required three people to break the barrels loose from the action, one on a heating tip torch to heat the front ring, one on an inner insert wrench and one on the outer Mauser action wrench with a 4' extension. Many times they would sound like a 22 rifle when they broke loose and many also had a white thread locker in the threads. We would do a dozen 98s at a time.

Today, I set my Mauser re-barrel jobs up to a crush fit at the same time for the inner and outer rings and have found that the double crush fit of .002-3 produces consistent .5 or better accuracy with a decent barrel, when the action/ bolt is squared with 100% lug contact and setup on a mandrel.

Amazing. I've been very lucky, in a half century of Mauser disassembly...I have yet to have any difficulty removing bbls with the barrel firmly held in the press, a 32" action wrench and a 3 pound lead hammer. Never once applied heat. The white substance you see, in my opinion, is not thread locker...it is white lead, the do all panacea of machine work the world over until the 1980's when lead fell out of favor in the workplace.

Thanks for the input. I guess I'm going to try for contact on both surfaces with maybe a half a thou tighter on ring

I hit on the ring two thou ahead of the c-ring. When tightened, the barrel sits hard on the c-ring as well as the ring. Once solid contact on the inner c-ring is made, that barrel won't turn on any more. GD

I have 4 Mausers with Savage style barrels with a retaining nut. None of these barrels seat on the inner ring but rather the outer ring. All very accurate and never a problem.

It really isn't so hard to barrel them "the right" way.

Thanks much for the tech information in this Thread discussing "barrel replacement trials and tribulations..." Four foot long iron bar 'come alongs'! Conjuring never to let my trusted guns be subject to such harsh procedures! Such words here of graphic imagery underlying the Govt tech term: "Project Disincentivization"

Shades of personal past. Lying there on the surgery table as the "Twilight Sleep" injection not working at all. Overhearing my Surgeon graphically chatting with his "Team", concerning the mechanics & hazards of my MY hip replacement about to commence...! Surgery, AS... "Sawing off my Upper Femur, driving a long spiked ball into the soft bone marrow! Grinding down my whole damned hip socket & plastic replacement cinched up with screws into pelvis! And hopefully... "Humpty" back together again! The smiley face of my Anestheologist, noting my yet awakened state with "Oops!" Not a confidence inspiring term in surgical environs! 'The' Disincentivization Moment there! As 'maybe signals off'; time out to rethink'! But for...' A pesky nurse, seeming only moments later, flouting "Too late! All Done!"

OK, maybe just a 'bit' off-subject in a Gun Blog and apologies Dennis and all! But taking 'war story' opportunities' where finding them!
Best!
The 'Gimp'... Only kidding!
John

Best of outcomes Iskra, seriously...tip, after the scrub, pull , out your inside waistband carry magic marker and write NO! on your good leg.

Hope it went well

I bought a new threading tool that uses full profile 55⁰ Whitworth threads. It did a great job. Now if i had a stock...