Cast bullet pressure

[drone]

I have the Lee 2016 second edition manual, Lyman 49 manual and the Lyman 4th edition cast bullet handbook.
In the Lee manual he expounds at great length regarding the deformation of the bullet base as pressure increases and exceeds the strength of the bullet which significantly affects accuracy. I load for 308, 30/30, 223 and 357/38S and the number of load data regarding cast bullets is limited at best in the Lee manual.
Both the Lyman publications do not appear to make a detailed reference to this phenomena and, in fact, in the cast handbook lists cast bullet loads way over the Lee imposed limits eg Lee says 19100 psi max for best accuracy for lyman #2 alloy whereas quite a few of the lyman loads are far and away above this.
TBH I don't load for high muzzle velocity preferring to use cast bullets for under 200 yards and am quite happy with velocities below 1800 fps which suit my purpose fine.
My question of the month is how seriously do the more experienced reloaders regard the Lee theory? I ask this as one has no easy method of ascertaining pressure, the Lee method of establishing hardness borders on the subjective and I'm thinking of changing my forum handle to Baffled of Dover.
I'm coming round , slightly tongue in cheek, to the view that this is a sales pitch to sell more of his hardness testing devices, am I wrong?

[GasGuzzler]

Leading is caused by excess pressure and/or poor bullet fit ... usually. Most times you'll see leading way before major bullet problems. Trouble is, we can't easily load for pressure or measure our loads for pressure. I do know, via extrapolation, many of my cast bullet loads are much higher pressure than 19100.

I would have to go outside and get my copies of the same books and see the context to make a better answer.

[RBHarter]

Every manual is 25% data , 25% instruction , and 50% sales brochure for the best of the best w/honors .

I don't know what kind of pressure is generated for a 255gr bullet to break 2000 fps MV, well 10ft out , in a 19" 45-70 Marlin but Id bet it's tiptoeing around somewhat above 25kpsi . I know that a max jacketed load for a 180 gr using a 401-175 at 181gr gets me 980 fps at 10' from a 2.5" XD40 which is about 35kpsi with a jacket .
I know I've run gas checked rifles well over 40kpsi as I don't think you can get a 62 gr 222 to 2640 fps without it . I also have no idea where IMR 4350 is in a 358 Win but a 35-250 is in the core of jacket speeds at 2100 fps and it's over 30kpsi .
Paper patched failed to lead , which is kind of the idea , way , way past 55kpsi . I know it was way past that because the goober that loaded it used 130 data with H322 and later discovered that his 27-130 FP weighed 141gr before the patch and gas check....... I'm smarter now . In the 6.8 SPCII it take about 55kpsi to get a 130 to the 2450 I was getting with the 141 gr never mind the next .2 step resulted in both the primer cup and anvil being vented somewhere. Twice . The 9mm and 357 both run 30kpsi in my loads being under but not far off top jacketed speeds and I guess are something close to #2 . The top level 45 Colts into start Rugger loads and 45 ACP are 20-25 kpsi with considerably softer alloys as a 45-200 SWC will double dia in live oak .

[Macd]

Lee's theory on pressure, lead bullet deformation and accuracy is interesting reading. FWIW my own experience is that non-checked bullets made with wheel weight lead with added tin give best accuracy below 2000fps in my rifles. Sub-sonic accuracy is also usually great. In some cases such as 35 Remington I can match factory ammo performance below this with pressures taken from the Hodgdon tables of around 30k but I now only use a commercial hard cast in this rifle that is checked.. Add a check and I am able to get close to jacketed speeds in rifles that take a 308 bullet before accuracy drops off. In pistol my IPSC load was producing 27-30 depending on powder for a plain based bullet. In revolver the 45 Colt table pressures were 12k to near 14k. This is the only gun that gives me some leading issues.