Jerry, I know that not all proof loads are as you describe. A common complaint about the British proof houses is getting your new expensive pride and joy back from proofing with a ring etched into the bolt face from a primer leak or blown primer. The Osprey Rifles built Stolle action 308 FTR rifle that I had built for the FCWC at Raton two years ago was just such a 'victim'. As one who's avoided this with handloads for over 30 years in the game, I was upset - to put it mildly! Peter Walker (Walker Rifles) who has built many of the UK's most successful F-Open and Benchrest rifles and is an absolute perfectionist is driven near mad by this.
However, one rarely (more likely never) sees this with factory rifles. Over-long throats and none too tight bores methinks, unlike custom built jobs.
My most interesting 'over-pressure' load was with a factory (Norma) 270 Win cartridge. Years back I did some work for a local gunshop and they had a big box of old Norma 130gn PSP ammo sitting in their warehouse with a 'Do not sell' notice attached, but nobody could remember why not. I took a box of 20 and put 10 through an old but very nice Brno ZKK600 sporting rifle and chronographed them. The first nine, nothing out of the ordinary, if rather hot loads. #10 no different in recoil, same MV as the others, but it was a case of stand up from the bench to pull the bolt-handle up. The primer promply fell out as soon as I extracted the case which was noticeably expanded above the extractor ring. Soft brass of course, not excessive pressure, and the manufacturer had put out a recall notice on the production lot.
This is the point about this issue. There are no over-hot loads across the board. Pressures that are normal in a Weatherby Magnum would wreck a 32-20 levergun; pressures that are low in most rifles will destroy most handguns. Lapua created a very strong case with the Palma model .... all its cases are strong, this one a bit more so. Remember though that it wasn't introduced to allow people to get another 100 fps or whatever, but to reduce ES and SD values. I've little doubt that the ammunition issued to the Palma lads and lasses at Camp Perry later this year won't be any higher velocity than the previously used LRP Lapua loads, or Winchester brass based ammo before that, or LC (??) back in nineteen oatcake. Heavy FTR loads with this brass is no more or less risky than hot loads in any other cartridge, and F-Open competitors are using equally strong brass in their short magnums, not to mention many sporting shooters with their elk rifles - Kenny Jarrett et al with the STW and similar.
As Jerry says, it's then down to the individual and responsible / knowledgeable handloading and load development. One can't accuse Winchester of being somehow irresponsible by designing the WSMs to run in factory form at 65,000 psi, 3,000 more than 308 as a strong case encourages stupid people to do stupid things. (I bet there are more blown up handguns with their <20,000 psi pressures each year than there are equivalents amongst rifles using modern ammo designs and very high pressures.)
Personally, I'm 100% with you Jerry (being a coward)! I like a margin. However, it's all relative. My 155.5 Berger 3,050 fps small primer loads (from 32-inches) may be down on some people's MVs, but speak to shooters in other disciplines and mention those sort of speeds and they either disbelieve me or regard me as some sort of dangerous nutter.
As to judging pressures with QuickLOAD, I'm with you too there Jerry. Excellent aid though it is, there are too many variables to judge pressures that finely. One is primer / flash-hole type and QL can't differentiate between Palma and ordinary 308 ignition whilst those who use both know that the Palma type usually needs an extra half-grain charge weight to match standard brass MVs. FWIW, I ran my 2013 (155.5 / IMR-8208 XBR) load through QL to see what pressures it calculates, and if I believe it, I was running a 68,001 psi PMax for a couple of years including at Raton with its 90-deg plus temperatures. However, I was also getting 50 fps higher MVs than my Magnetospeed says. Change the variables to come down to 3,050 fps and the program says this combination runs at 64,575 fps, but I don't believe it's actually that high.
Incidentally, at Raton the precise load I'd worked up in our very much cooler temperatures in the UK was still the one that produced the smallest groups with a tiny velocity spread, but MVs rose to just short of 3,100 fps.
