Actually Canuck325 is quite right, they are only guides. If your going to get into reloading you better take his comment seriously. Yes there are quite a few manual loads that are well under YOUR guns safe limits, there are also a few loads that are OVER safe limit. I've had my Ruger 77 bolt freeze with max loads from one manual that I took for granted would be good. Work safe & don't take anything for granted, even from a Manual! Always check a load against a couple other manuals to make sure their in order!
I think you missed the point of the debate. If you look at his velocity claim then it is clear that he MUST be way over the maximum SAAMI limit for that cartridge.
Nobody who has significant reloading experience will argue with the fact that different rifles will have different maximum charges. Some will take a higher maximum charge because they have more throat erosion, but that throat errosion also lowers pressure.
Like I said, there is no free lunch. Higher pressure = higher velocity. That is why, imo, a chronograph is a very important tool for load developement.
Let me give you an example. If you look at the reloading manual you will see a charge for a given bullet, and a velocity. Now the velocity can and will vary for a number of reasons - barrel length, altitude etc. Even the twist rate affects the velocity.
The Nosler manual says 56.0g of RL 22 is the max charge and it gives 2982fps out of the 26" test barrel.
Now you may have a 24" tube on your rifle, and it's chamber and throat will be different than the Nosler test rifle. But let's say you start at 52.0gr and work your way up, watching the cases and the other signs, in addition to the chronograph readings.
You may get pressure signs before you hit the max charge or velocity listed, then stop. You may have no pressure signs at the max charge, and you may have not reached the velocity listed under max charge (taking into account the shorter barrel). The you can make a decision on what to do next.
BUT my opinion is that if you reach the velocity listed under the max charge you are at, or very close to maximum SAAMI pressure! It doesn't matter what the charge is (it could be lower than the listed maximum).
Since Canuck claims at least 175fps faster than the max velocity, he must be far over SAAMI pressure limits. SAAMI pressure limits are there for a reason. Sure there is a safety buffer, but that buffer is there for a reason: SAFETY.