Hogwash.
Mausers typically don't make for good target rifles for a couple reasons. 1. The lock time on a Mauser is EXTREMELY long, and 2. the receiver is weakened by the thumb cutout on the left side for using stripper clip. If you're going to go to all the trouble of building a nice target rifle, I would suggest you build on either a Model 70 or Model 700 platform.
Talk the talk, or walk the walk. I've got a Krieger-barreled 1916 Haenel 98 Mauser in 6.5-06 that shoots 1/4 MOA, and I got the idea to build it from many other target-grade Mausers I've seen in the last 30 years or so. This particular Mauser centerpunched a golfball cold-bore first shot at 500 meters, I've still got the ball and the article in the November '99 Tactical Shooter magazine that tells the story. Nor am I totally biased or ignorant of what makes a good target rifle, I have a Remington 700 PSS which shoots groups almost as tight as the wildcat Mauser above. The Remington is cheaper to tweak, but the Mauser is more fun, and has a nice in-your-face personality on F-Class competition day.
Now, about the supposed negatives of the 98 Mauser action: If one is so worried about lock time on a 98 Mauser, simply get the Tubb Speedlock kit, and a decent trigger. I have both the Speedlock striker/spring kit, and a Canjar trigger. I've never felt handicapped at all by the allegedly slow locktime.
Likewise, if that receiver is so darned weak because of the thumb cutout, we'd be hearing about it from two world wars' worth of casualties when the receiver let go or at least caused the Axis concern because of the sloppy shooting characteristics. For anybody but the most serious benchrester with a Nesika Bay or Stolle Panda rig, the 98 Mauser is quite suitable for target work. Even the less refined precursor to the 98 Mauser, namely the Swedish 96 Mauser, garnered a well-deserved reputation for stellar accuracy straight from the Carl Gustaf and Oberndorf plants. Truthfully, with that big forged lump of German steel, receiver flex is a non-issue. Bolt lockup when in battery is an issue, as is proper chambering and headspacing. While Mausers may be loose as a goose when the bolt is wide open, they're secure as a Swiss bank vault when closed, if properly smithed, and that's where it counts. (We don't fire rifles with bolts open where I come from)
Where people get their panties in a wad with respect to 98 Mauser target/precision/varmint/rebuilds is the cost of conversion. That complaint, if you can call it that, is somewhat valid. 9 times out of 10, it'll be cheaper to buy a Remington 700/Savage 110/Ruger 77 rifle and commence tweaking. (Forget the Winchester Model 70, now that it and the Winchester Model 94 are discontinued) Then there are the collectors, like myself, who are loathe to cut up or otherwise discombobulate a nice original specimen of a military Mauser. That leaves mongrel Mausers, those that Bubba already took a hacksaw to, or loose actions that float around in desk drawers until the late owner's widow finally sells it at a yard sale as a paperweight or through a friend of a friend. (Don't laugh, there are a bunch out there)
Regardless, with a military Mauser action, one has to drill and tap the receiver, change the safety lever to a low-swing model, forge or weld the bolt handle to clear the scope, blueprint and square the receiverface and barrel threads, fit a new barrel, cut the chamber, headspace it, etc. Then one gets to fit the barreled action to a stock, free float the barrel, do the Devcon action bedding trick, adjust the target trigger(s), and proceed to tune the gun for a given ammo load. That's somewhat more labor and money intensive than going and buying a Remington 700 Police or Varmint model, or a Savage 110/10 target/varmint model. The monetary argument is indeed there, but for my purposes, I find that the uniqueness of building and shooting a serious 1000+ yard target/interdiction gun on a good solid 98 Mauser action outweighs any savings on a similar gun built on a Remington or Savage action. Anybody can go and buy the latter and be shooting tight groups fairly quickly. It takes a dedicated person to build and shoot a custom target 98 Mauser.
BTW, I'm in the process of building an almost identical clone of the one above, this time in .308 Winchester, for the other category in F-Class reserved for that particular cartridge. The receiver is a blueprinted byf 1942 Kar98 action. So by all means, if you want to build a custom target rifle on a 98 Mauser action, you'll have a fine shooting gun. Just remember it won't be worth a whole lot with respect to resale when you're done with it, and it won't be as cheap to convert as it would be to buy a new Remington, Savage, or Ruger.