"All cases had 34.6gn of Varget except 5had 35gn, 3 had 36gn & 1 had 37gn
I went back to Hornady Load Book and 34.6gn is absolute Max for 55Gn V-Max bullet
The loads I've been making are for 50Gn V-Max bullet. (which I used previously)
Max amount of Varget I could get in a 22-250 case is 39gn
Looks like I've been living on the edge for quite a while."
Not so fast..
Now obviously we all want to be safe and must be very careful when reloading etc, so consider all the safety issues as, well considered. Now, let's look at real world 22-250 reloading, using 55gr bullets and Varget. The Hornady handbook is notoriously conservative, I can go into it if you want but let's just note that for now. The Hodgedon reloading center lists 36.5 for a spr sp as max. Other handbooks vary, so the takeaway is that max is not consistent for a variety of reasons. The most realistic thing we have to remember is every shot is a combination of ammunition with all of its variables and the firearm it is fired from, with all of its variables with the environment that it is fired in with all of its variables. You can look around shooting forums and find people that load this load up to the Hodgedon level and higher all over the place. Are they wrong? Could be. But it's only wrong if it's wrong for the particular set of variables in play for a particular situation. The max loads are meant to provide a safe margin for handloaders and if people work up their loads correctly, watching for pressure signs then going up to the max (and dare I say beyond, with the rather obvious caveats) is fine.
We can glean several points from all this. First and foremost, we cannot take anything for granted and even assume a maximum load printed in a book is "safe" for a particular set of variables and conversely that maximum may not be a maximum for some other set of variables. One person may be shooting at 30 degrees F, temperature insensitive powder, have a beefy rifle with a long throat, brass with higher volume etc, all making for being able to shoot a load higher than "max". Another person will see definite pressure at well below max because he is out in the summer sun shooting bputs all day long and his rifle/ammo combo is more prone to pressure.
Secondly, we cannot assume anything about the variables involved in our shooting. We strive to have consistent ammo, but as you show here, you have a pretty wide spread in powder weights that would make me swear off powder throws forever (assuming you are using a throw). But even if we do have perfectly consistent loads, what about our shooting conditions? What about fouling, what about... well you get the idea. We also cannot ignore the combined affect of our variables and sometimes we have to be careful to not overestimate the affect of some variables. There is a fairly reliable story that an early and prolific adapter of the 22-250 was known to take a case and dip in a container of W760, I think, brush off the powder from the top of the case and seat a bullet. It would not only be fine but even fairly accurate. The 22-250 is one of the most forgiving cartridges to load one can find, not that I would recommend doing what this guy did.
Lastly, due to those variables that same ammo that you work up for your rifle and works fine, could be overpressure in someone else's rifle, or at a minimum, could have totally worthless accuracy. Or, holding the ammo and rifle as constants, you could find your rifle shoots great early in the morning while cool and loses accuracy as it heats up or maybe even shows pressure as it heats up. Who knows.
As for pressures developed with Varget etc, and did it blow your rifle up as a matter of over pressure, I'm not so sure of that. The pressure it took to do that to your rifle probably cannot be achieved with the amount of Varget you can fit in the cartridge. This is certainly speculation but that is a lot of damage and most guns are proofed in the factory with loads that are likely in the range of what a full cartridge of Varget would be so I'm skeptical that this was the issue. Proof testing in most cases specifies 25% over max pressure so that puts the rifle as being tested at over 80,000 psi, which I'm not sure 39gr Varget will achieve and if it can, how much more can it achieve since the rifle has already be proofed over 80,000. I could be wrong but that's how it looks. Glad you were not hurt.