Potash - Something wonky here, my old Lee manual shows 49 g max load for H4350 and 175 grainers...
Yeah - is a thing with having more than one source of data - often, they do not agree - have to read the fine print, I guess. I checked again, what I typed in Post #6 is what is in the Hornady #9 and the Hodgdon 2011 manual - I did not make a typo or misread, although very possible for me these days!!! I also looked in Lyman 49 - again, for 175 grain Speer Grand Slam #1643, they do not report for H4350. Does not mean is not suitable - just means those sources did not report on it. From Lyman 49, they do list IMR 4350 - is often close to H4350 but is not the same - they show Start of 41.0 and max of 45.0. Lyman data also reports using Winchester cases, WLR primers - they do not report the resulting pressure in either CUP or PSI for those loads.
Speer #14 manual does list H4350 with Speer Mag Tip SP and Grand Slam SP 175 grain bullets - 41.0 Start and 45.0 Max. Remington cases, CCI200 primers (CCI250 for ball powders). On page 360, says SAAMI limit is 46,000 CUP for 7x57. Speer thinks European ammo is loaded hotter, so the loads they report were developed to maximum pressure of 50,000 CUP.
Nosler 9 book reports H4350 with their 175 grain Accubond and Partition - page 380 - Start is 41.0 (marked as most accurate) and Max is 45.0. They also used Winchester case, WLR primers in a 1-9" twist 22" Lilja barrel. I do not see where they report on the pressure limits that they used.
Also, I do not think that the Lee organization does pressure testing - they publish loads they got from someone(s) else, previously published data - previous publisher did that testing (I presume). I really do not know where Lee gets their information from - they do not do their own pressure testing, though.
I have found to compare recipes - need the complete recipe - what brand of case, what primer, what style of bullet - all can be different - some make no difference; some makes a lot of difference. And every manual that I have says you must start at start level and work up in steps - every time that you change a component - you may or may not get to the maximum that they report, or you might go past their numbers - they are reporting what they got in their gear - with their components - they did not use your stuff to test the pressure level that they reported.
But remember - they have actual pressure testing devices - us home hand loaders do not. From numerous articles and investigation, about the best surrogate that we have for pressure is muzzle velocity - when we get same speed, with same components, allowing for barrel length differences, we are at the same breech pressure. Might have taken us more or less powder charge to get there. Most all other "home signs" like primers flattening, bolt opening, etc. have been shown to work sometimes and to not work other times - so not really dependable, like muzzle velocity.