I got you PM. I am a bit distracted now, sending some things to the Hurricane relief - “In confusion there is profit…”
I believe you will get some good case forming details from Donnelly’s book. Only the cartridge drawings detract from the book.
I do not believe you need any other software than Quick Load. Quick load should handle all of your early predictions. Personally I use single base powders for me initial load work as single base powders deliver a more predictable performance. After I have established what the single base powders will deliver, I move to the ball powders of similar burn rate.
Either way Quick Load will get you close quickly.
The criticism of RCBS Load is based - I believe on the early version. We started with RCBS Load when it was on the large floppy disc - version 2 - and our computer was a 286 Dell. RCBS Load ran slow and many features were spotty. Greg Mushial from GMDR never failed to respond to our questions and his advice was helpful. Greg has modified many of the features and today’s faster computers make a big difference in how RCBS Load functions.
The Cartridge Designer function is now quite easy to use and has many additional features which are “useful” - at least they help pass a the winter evenings…
Designing a new cartridge is easy and modifying your drawings is not difficult. Greg has added color printing and multiple bullet shapes which is a nice feature.
I just put up a cartridge - .25 Souper in this case. When you have the cartridge up on the screen and select “other” at the bottom of the tool list you can bring up cartridge characteristics. This chart will give you a great deal of detail on your cartridge case which helps with reamer and custom die thoughts.
Of interest to the wildcatter is the bolt thrust and pressure max at specific points in the barrel. Radial thrust on the barrel etc. This information is not as detailed as Quick Load but RCBS Load is not intended to provide specific load development information.
As you edit your cartridge estimated pressure you change the characteristics of the case. I assume Quick Load does this but I have very limited experience with Quick Load.
Nick and others on the board have experience and can provide a more in-depth comparison of the programs.
A feature of RCBS Load which I believe Quick Load shares is the estimate of uncompressed cartridge case capacity for various powders. As you vary your case design - body taper, shoulder angle, bullet seating depth etc. RCBS Load will adjust the case capacity measurements in grains of water and by specific powders by full case, capacity without the neck and capacity with the bullet seated to whatever depth you desire. RCBS Load has a database of at least 105 different powders.
Greg and I have discussed his method for determining and confirming powder density and he spends quite a bit of time ensuring his powder density figures are correct.
This information is not load data but is intended to assist the wildcatter in establishing his case capacity. The wildcatter often designs his cartridge for a specific performance goal - often with the use of one specific bullet in mind. The ability of these programs to estimate cartridge capacity for several different powders - instantly - as you vary case shape/volume is very useful.
This brings up the advantage of Quick Load as you are able to quickly estimate optimum powder charges and estimated pressure. I still use the Powley Computer for Handloaders as I primarily use single base powder for initial load development. I am an older guy and I think better in CUP than I do PSI. I have a spread sheet which works a lot of the Powley math quickly and I can estimate chamber pressure, muzzle pressure, velocity etc quickly and while I would enjoy Quick Load it is not a pressing priority for me.
As you can imagine, I am in the stone-age compared to most of the wildcatters on the board. Marrontoad (Snow) and I have compared some Load From A Disc information and I find the information very useful - for use with my preferred single base powders.
I’ll draw a few pictures for you. I am attaching the picture of your cartridge with the shoulder, the bottom of the neck and the case length cut by .2". Leaving the neck long looksodd. I'll draw that one later. I am not a 7mm guy so I don’t have many 7mm component bullets in my collection so if you are to post the overall bullet length it will help to estimate seating depth.
In general terms it is hard to predict the effect of different throat angles on internal pressure. For the best thoughts on internal ballistics which are understandable to a “simple” mind such as mine I recommend Lloyd Brownells Firearms Pressure Factors which is available on CD from Wolfe Publishing. I have the book and the CD and I believe the CD is more useful to those who will actually use the math. Even if you don’t intend to spend your evenings working your calculator overtime the book answers many questions about internal ballistics and will give you a better idea of what you are able to predict.
I believe Denton is posting on the Beartooth Forum and he could probably add some thoughts as to how throat angle and free bore affect pressure.
I drew your cartridge with the point of the shoulder pushed back .2”.
This puts the shoulder at 1.3383” and I shortened the overall case length to 1.835”. The bottom of the neck is at 1.5242”.” deep, to the bottom of the neck, I estimate the water capacity at 56.6 grains of water.
With the bullet seated to the bottom of the neck your estimated case capacity for IMR 7828 would be 49.94 grains of powder.
You have enough room for 51.0 grains of Alliant Reloder 19. Gain this is not load data simply capacity.
The maximum loads listed for the 7mm Remington Saum with 160-grain bullets and these powders is 63.0 grains of IMR 7828 and 60.0 grains of Reloder 19. These are shown as uncompressed loads.
I would run some side by side models of the 7mm-08 to look for optimum powders and to compare muzzle pressure with your intended barrel length.
I had a reason for drawing the case with the neck shortened first and I'll get up the drawing of the case you ension as quick as I am able.