To be quite honest, I do not generalize the number of rounds it takes to find the ideal load. Mainly due to as mentioned, when I purchase a rifle or handgun, it is done so because I wanted to shoot something different or wanted a specific caliber.
I have also found through the years, that most times life in general has a way of getting in the way of me sitting out on the range and working up a load the way I really like too. If I were retired or single, or didn't have a kid and grandkids, well it might be a bit different, but then I would still be riding the tractor, fixing fences, painting houses and such so either way it all boils down to time for me.
I completely understand about low funds, and apprehensions on purchasing bulk components, however in the time your using to conserve your funds, study the manuals, study the bullets, the powders, and categorize them into a small spreadsheet type files for your rifles. List the most often used across the board, which seem to keep with the bullet weights you intended to use and what OAL they used. Then look closely at the velocities produced by these powders, and what barrel lengths they were tested with. Granted this doesn't always mean a thing when it comes to your rifle but it does start to show a pattern. While your doing this also pay attention to powders that might be a good cross over to something else your loading. This also saves time and money in the long run.
Once you have your list narrowed down to the better of say three powders, and possibly two to three bullet weights, then your ready to get on with the loading. It's almost identical to what GB was speaking about. Ok so now you have a couple or three powders in 1# jugs, which possibly work for a couple of your rifles. They don't all have to but if two do then your that much more ahead. If more do then your really working things. IF you want to conserve components use the method above. Either way your off to the races, so might as well get a jump start. Since you have been studying the books, you should know the charge weight ranges for each powder you picked out. Figuring as GB does, works for me just as well as it does for him, but for you keep it how you like it and feel comfortable with. Load up your rounds and head to the range and test as noted above. You should hit a couple of good loads pretty quick.
Myself, I work it from a different angle. I hunt with my rifle, but I also demand the best accuracy from them I can possibly squeak out within the abilities of the combination. Part of this combo is me, and is usually the determining factor in the end. I do a similar accounting of powders which might give me the best overall loads both in velocity and accuracy.
I also look at the velocities and generally decide upon something based upon what the load is going to be used for and with what bullet. I know that a 100gr Partition from my .243 will do wonders at the top end of the spectrum, however the 95gr BT with the same load will blow a massive cavity out of a deer. So I would rather shoot the 100gr fast and drop the 95 down to around 2800fps where it isn't quite as destructive. By the same token, for the .270 I run the 130's at top end and keep the 150's down around 2750 simply due to they are used in the wood and the 130's are for wide open areas where shots might be a bit further.
So after deciding on the destination of the load. I fill up my Uniflow and start weighing charges of the powders I have chosen then recording the stem settings as min and max next to the powder being weighed. This lets me quickly set the measure up for several powders while at the range and not have to have my scale there to weigh each and every charge. I toss in between 20 and 50 cases, and enough bullets and primers to test for the whole day.
I set up my OAL based upon the mag lengths to start with, and work up from there. I don't worry about how close to the lands I am or even hitting them as most of my rifles aren't even close with a mag length case anyway. I start dumping powder and seating bullets. I run them across the chrono and check velocities on my way up. Generally I will shoot two to to three loads for each weight. This results in a target somewhat like this,
and my load set up looks like this,
While this may or may not be a totally acceptable practice among some shooters, it has worked wonders for me over the past 20 or so years. Saves me time and effort running to and from the range to load or pull rounds just to go back and try them again. This .243 was known to shoot a 100gr bullet very well. It put this 5 shot group together with the cheapest box of factory ammo I could find for it, the first time I shot a group with it. It has done it since several more times so I know it will shoot.
The loads I worked up were with the then new Hybrid-100V from Hodgdon. The barreled action had also been placed into a replacement stock just two days before with no fitting ir fussing about it. Just simply dropped in and snugged down. The results were found that it does need a bit of barrel channel work as is noted with the two bottom left groups and the two risen flyers in each. These were both the last two shots of each group fired in succession. If I let it cool they will all be together. There was also a seating depth change of .015 deeper which also closed up the group from the top row, L to R groups 3,4.
Have I tried any other powder with this rifle, nope and probably won't. It simply shoots just like I want it to and hits the 3100fps with the 100gr Nosler Solid Base just the way I wanted it to do. So with a few bullets and one powder, I found something we both liked.
Now will all rifles do this as easily, well it seems to be getting easier as I get older to get where I want to be quicker. I generally use this method on them all nowadays and it seems to come in pretty quickly. Sometimes I even have to change powders once or twice, but once you get the hang of it and know what your looking for, you can tell pretty quick if the load is going to get up where it needs to be, and either accept that area or drop the powder and start with another just that quick. I can vary the powder in small increments at the rsnge or simply do the rough in, and bring everything home and load up a box of tightly tweaked loads, and go back at a later time. However when I leave, I still have loads which are plenty good for any hunting I might do with the particular rifle I am using at the time.
