You don't unless you do your own research and check proof records or you know the rifle doesnt have a fluted bolt from factory and you can ask the seller about it being in proof. A guy here in the UK had his bolt fluted and this happened, was it a metal flaw, an ammo issue or was it because of the fluting...who knows. But if it's proofed after fluting it covers your own back if something like this happens and someone gets hurt. For how little it costs it's not worth the liability.
The bolt handles abilty to take the thrust force under a lug failure has not been proved by the proof test. So fluting would not hsve invalidated that, which was not and could not be tested. Good question though.As you say with a a bolt with forward locking lugs it should not weaken it for primary pressure bearing.
However I've often read that the bolt handle locking into the receiver is considered to be a third/fourth safety lug in the unlikely event of bolt failure. Therefore could fluting the bolt possibly be considered as weakening a potentially pressure bearing part and thus require proofing?
Proof records only record muzzle thread present or not, they don’t record fluting of barrels, bolts or even barrel od, which in theory could be reprofiled and invalidate proof without removing the marks. All that can be checked is that there are proof marks at chamber and muzzle if threaded.
I was joking. Interesting that ceracoat is so tough, only yesterday i was trying to remove some of it from a barrel that was reclaimed from another rifle due to poor quality work on both the tennon and muzzle threads. The stuff is really tough, barrel spinning at 2000rpm and 600 grit silicon carbide doesn’t touch it.
Yes, severely. The case head expands and forces the bolt nose outwards. It then fractured at the weak points/stress risers of the extractor and ejector cuts. The fracture then propagated down the bolt body and in to a flute. It has nothing to do with the fluting even if they are a bit close to the lugs. The T3 bolts are a extremely hard stainless and tend to be a little brittle.
Selling a chambered barrel is classed as a sale of a firearm/component part, therefore it must be proofed. If you chambered your own barrel then it would only need proofing if you sold it. Fluting a bolt or threading a muzzle is not a sale, it’s altering the part. So no need for proof until you sold the rifle. It’s quite clear cut
If it was done at the proof house, it proves it is the right thing to do after any work is done, and before it's handed back to the customer.
These had fluted bolts that were most certainly not "bling"!As I suspected, "bling".......
D
You don't need to be a Professor of Metallurgy to know the bolt body fluting played no part in the head's failure, but point taken regarding Proofing and third-party liability etc.
