Interesting!
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Question: Why is there no maximum pressure listed in any of the standard tables for 44-40 including SAMMI?

That is a neat spreadsheet!  Looks like you just relabel a column to what round you wish to test, - it seems to have most calibers, just remove the ".45 ACP" and make it ".45 caliber" column, then you could us it for any round you wish in .45 caliber by changing the barrel length, bullet weight, barrel pressure, or velocity.  You can add any caliber you wish to the SAAMI sheet.   

"IF" I understand this, say you wish to see about 45-70 - then use the 45 caliber column.  Plug in your desired bullet weight and barrel length.  Say, 500 grain with 30 inch barrel.  Now, most of us don't have a way to measure pressure (some do), so we measure velocity and find we get 1000 fps (light load).  The results show we only have 8,338 PSI chamber pressure.

Now, I have a question about that - does that hold valid with BP as well as smokeless?  What about a fast burning pistol powder in that big brass vs a slow burning smokeless powder?

They indicate that bullet velocity is a direct result of chamber pressure- if so, then it's a VERY valid spreadsheet and I'm VERY thankful for the link.

Looking for comments.

Ken H>

This is great. Thank you.

Ken, wouldn't a certain diameter projectile, in a certain length barrel need a certain amount of pressure to achieve a certain velocity.

You could substitute any parameter for X and it would give you the number

I used the 357 mag area to figure out pressure for a 38-55, 255g bullet, 30" barrel, .375 diameter at 1200fps 

It returned 8,857 psi

Seems low?

You would think the type of powder SHOULD factor in. But pressure is pressue...the only variable will be "rise time"...This is where it gets tricky because few documents get into this area.

For example...Everyone is screaming about Trail Boss...Low pressure but incredibly fast pressure spike. I'm convinced that a slower pressure spike is better for our older firearms than a real fast spike. Black powder can generate lots of pressure, but my understanding (and I may be wrong..Please correct me) is it spikes much slower...this is strange because BP is an explosive and you'd think that characteristic would make it spike like crazy. But as we all know BP is more of a "shove" than a "smack"......
I'd like to learn more about all this pressure stuff. 
If I could find a Oehler Ballistic Lab for a reasonable price (or borrow / rent one) I'd like to take a week and sort out all these smokeless VS BP loads we are all screwing around with.

Maybe Santa will be good to me this year! I want one of those!!!

Gee, if it was just a matter of max pressure wouldn't we all be using Bullseye? A kick may give you a start but a shove will keep you moving. The burning rate/pressure combo is the key.

I should drag out my old Powley computer and check out my latest loadings. Have not done it for yrs, but I recall, when designing "wildcats" that the Powley predictions were rather close to my actual results across my Oehler 33.
Its based on case capacity/expansion ratio, etc
beltfed/arnie

Ken, here's an example for the 7.62x39 with a 150 grain Sierra from the Accurate manual max velocity and pressure:
By Pressure: (LT-32 41,434 2056fps) (2015 41,736 1950fps) (Ramshot 48,241 2161fps) (2200 48,698 2291fps) (5744 50,002 2176fps) (1680 51,402 2109fps)
It shows that pressure and velocity don't necessarily correlate and that there is an optimum powder to produce the highest velocity with a not excessive pressure. I'm glad someone brought up the old Powley Computer. That uses the factors that influence arriving at the optimum load and it works quite well in determining the best powder with the amount to be used, the pressure generated and the velocity achieved.