Where I'd start...
Contender,
First off, I would get ahold of several reloading books, at least three - more is preferred.
I'd then do some comparison checks. Try to find out which cartridge is close to yours in case capacity, bore, shell type, shape, etc.
When you've narrowed down a possible list of candidates, it's time to start looking for consensus's in loads. As an example, and keep in mind that I'm just throwing numbers out - you'll find that three different load books list the 30-30 with a 150 gn bullet using somewhere around 33.0 gns of IMR3031 to get a velocity of @ 2250 fps with a pressure of around 37-38000 cup.
What you are looking for is a consensus between the different books. If they don't have similar loads for similar bullet weights, using the same type powder, getting the same performance, then find another example. Getting a chart where the burn rates of the various powders are compared with each other is a good thing to have too. Here, 'potential' substitutes can be found. I say potential, as some powders with similar burn rates might produce pressure at a different rates, especially in different cases.
Now, if your wildcat were a 30 bore, with a case capacity and shape similar to a 30-30, and by using 33.0 gns of IMR3031 (as long as this didn't exceed the recommended pressure for your action) you would have a pretty good starting point for working up a load. Of course, for safety's sake, you'd best reduce by 10% and start from there.
Ackley was real good about looking for high pressure signs in all his loads. Any good loading manual will have pictures of cases that show signs of excessive pressure. One should always be extra careful when approaching maximum loads in any cartridge, but I'd say that if you built up your loads gradually, you'd find optimum performance well before you were to reach maximum pressure.
Just shooting from the hip, I'd say that with your 270/308, you might find that some 7mm-08 loads would be a good place to start in cooking up some well performing loads for your Savage 99's. Just remember that there is a maximum pressure that those actions should never exceed, and all long as you don't do that, you should get along just fine.
Do let us know how you fare.
Unkel Gilbey
