Home Forums Hunting & Shooting Hunting Rifles big bolt/fat bolt vs reg bolt design

So,

Sauer 100 has a fat bolt design where the lugs are the same width as the bolt diameter. Tikka does not.
Seekins bolt v2 went fatter I think.

What are you experiences or preferences on way or another?

Thank you

Don't know if I have an opinion one way or another, but with a larger bolt, you have more surface area and more drag due to that. With the larger bolt diameter and the way the Sauer bolt is machined, the action would have to be larger in diameter than a standard 700 style action, or the action ID would have to be bigger making the action walls thinner (if the OD is the same as a 700 style).

I might could see the need if you were big rounds like a 338 Lapua or a 375 (or some other) CheyTec. Other than something like that, the standard .700 diameter bolt seems to have worked great for well over 60 years in the 700 and many more years before that in other models.

I know the thinking years ago was to sleeve the action (on target rifles) to make the action stiffer. About the only thing that was done to the bolts (that I know of) was to bush the bolts for them to have a tighter fit to the raceway of the actions.

I can’t think of a single way in which a fat bolt would be an advantage to me. The concept might be an advantage to a manufacturer, saving machining time. Tikkas are famously smooth, without one as you noted. My favorite action is the 98 Mauser, the Anti-Fat Bolt. It and its offspring were designed as Weapons of War as the Left likes to say, and for certain function under the worst of conditions, which makes them kinda loosey-goosey when the bolt is unlocked, but I’ve never had a problem running one quickly. As long as the lockup is even, I don’t think the size of the bolt body matters as to accuracy either.

My only comparison is between a Mauser M12 and a Tikka. The M12 bolt is every bit as smooth as the Tikka. However, with the M12 having dual ejectors, it takes more to run a shell into the chamber for full battery.

The only point of comparison I have is a couple of Weatherby MK Vs with full diameter bolt bodies. They’re a little heavy but they’re pretty slick compared to a 700, especially the newer ones with the rougher finishes.

Every bit as smooth as my Tikka . If I bolt body is fat it is because the lug design calls for it. Why would a manufacturer use a more expensive piece of steel when making the bolt?

At one point, the large diameter bolt was advantageous for the manufacturer because there was no need to cut full length raceways. With the advent of wire EDM machining, this was of less consequence. The downsides are a less rigid receiver and the need for a bolt stop which doubles as a guide. With all designs, there are compromises. One chooses those features which are important to him. GD