Originally Posted by modiver
I was looking at the Lyman 48th edition manual and it shows one load using Bullseye with a starting load of 4.9 and a max load of 6.0.
.45 loads will be all over the place for any powder and any bullet weight. The sheer volume of load data these days actually knowing which is what makes the process even harder to decipher.
This is due to the configuration of the bullet to some extent. If you set a dz different 200gr bullets on the table, they may have as many as eleven different heights. All bullets of the same bullets seated to the same overall length will have very different remaining case volumes, and demonstrate very different pressures due to that.
Variations in brass will also affect available case volume, and pressures.
Variations in primer intensity will also affect the pressure and velocity produced by a combination.
Start by determining the loaded length that will fit in the magazine, feed, and chamber. It's not unusual to find combinations that meet spec, that will not allow the slide to close on a given .45. I do this with a unprimed round, and remove the bullets with an inertia bullet puller, a safety thing. I usually use an OAL a bit shorter for some leeway.
Starting with the lowest load on the list, I load a slide full of rounds, or two, and make up a set with increasing powder charge at 0.2gr intervals. Often the lowest charge will not feed and/or cycle the action. When I hit a level that will reliably cycle, I increase that 0.2gr. Then I load up a batch of 50-100, and go from there. If I run into a couple fail to feed or cycle from that larger number, I increase the load another 0.2 gr, and so on.
Making full power loads for any auto takes some common sense and practice. It usually helps to chronograph the load to see if it falls in a range that makes sense for the bullet. If you get 100fps more than the max manual load, something is not right. If you're 200fps low, you can likely add more fuel safely. But not always.