Vic, you didn't mention what type of weapon you are loading for.
I have only used one powder in my mini 14 with good results, Win 748, so I can't offer you much of a choice in powder selection. 748 has worked well enough for me, but I don't shoot match. My Mini has a 1 in 7 twist and I have used 748 with a near max load of 25grs. with CCI SR Magnum primers under the Serria MatchKing 52gr, HPBT with good results. It shoots 55gr. bullets okay, with reasonable accuracy for paper punching also. I also have some Serria GameKing, 65gr. Spitzer BT but have not tried them as of yet. Bought them because of my faster barrel twist. But I can tell you one thing between the MatchKIng and GameKing bullets. The GameKing are much more consistant in length, diameter and weight. If wanting to shoot match, you might give that a thought when selecting bullets. Waiting on some Hornady 55gr. FBSP to try. Never tried a FB bullet in my mini before.
Either way, since you are just starting out into handloading, please start low and work up. Once you develope a load that works well you will then have to weigh and measure every case, charge and bullet to get the most from your handloads. Flash hole deburring will also help your loads to be more consistant. I believe every American commercial case is punched for the flash hole and it leaves a burr inside the case (At least everyone I have run across has). If you cut it out, you get much more uniform ignition
If you don't know your weapons twist rate you can use the tight patch method. Insert the cleaning rod through the muzzle With your bolt locked open, screw the slotted tip on the rod in the breech with a larger patch than you normally use for cleaning. Pull the patch into the bore a little and stop. Mark the rod at the muzzle with a small mark. Watch carefully and pull the patch through the bore until you see the small mark on the rod make one full turn. Measure from the mark to the muzzle and that will give you your twist. With one complete turn of the rod, if the distance between the mark and the muzzle measures 7", you have a 1in7 twist. Measuring 9" you have a 1in9, etc. Of course you may know all of this already, but just thought I'd throw it out there.
Take care, be safe. I am sure you will enjoy your new hobby.
If a man has nothing greater to believe in than himself, he is a very lonely man.
I reckon so. I guess we all died a little in that damn war.