It depends on the gun semi auto can be fussy and you may have to use round ball type while SW make a neater hole for sure. If scoring for IDPA for example it's the grease ring so round and sw ending up covering the same amount of real estate. The ball is more reliable and accurate, the SW is easier to see and score.
For me SW open my groups up by about 6 inches at 25 yards but in IDPA it is rare you shoot from that far so in IDPA accuracy difference between the two is a mute point.
As for loads don't waste your time and money get a crony and measure your velocity.
In less than 20 rounds you'll know if that combination is right or not and once you get in the swing of things you'll figure it out in ten rounds or less.
I paper test first so not to hit the crony then ten round across the crony.
That said if the combination doesn't group I don't bother using the crony.
It doesn't matter where it hits on the paper as long as you use the same point of aim.
Grab a slower burning powder or not start with a load that cycles the action reliably and add .2 of a grain to start. If working outside in really cold temps you need to add say .5 grain.
Now depending on if your casting your own bullets power and plays a bigger part.
So your better off test the hardness of your lead after it's cure time depend on your casting methods.
Then there is the lube.
The whole idea is to get the lead mix soft enough (keeps cost down like by 50%)
Once the planets are a lined your cost to shoot 45acp will be about $3.50 a box (50).
My costs all in except gear is $2.50 to $3.50 for 9mm or 45acp it varies due to the cost of lead and the hard alloy I have mixed up by Aim.
All lead will have something in it so I melt down lead in batches and test it then I know how much hard alloy to add to get #2 Alloy which I use for 9mm and the soft lead i use for 45acp. Hence 45acp cost the same as 9mm for me and .22lr (Walmart) cost a bit less at $2.99 a box. You might be able to do it cheaper bc I ship most of my stuff in and have include shipping in the costs.
So in a nut shell.
Every gun will have a type of bullet that works best, so shoot the original design.
What the bullet is made of and shape will make a deference
Powder and primer yes but not so much unless where looking for sub inch groups
Temperature
Use a scale to check your powder measure.
I use a measure that varies by .2 of a grain and my velocities are within 100 f/s of each other some are with in 20 ft/sec (batches)
I've seen some guys reloads vary by as much as 800 ft/s in the same batch.
A crony to a reloader is almost as important as a good scale.
And then finally there's you or use a rest and the it's not so much you
Last thought I forgot to mention is leading and not streaking that's why you need harder lead for faster bullets. So while it is posible to cast fast (light bullets) heavy slow ones have less variables to deal with.
Heavy bullets have more of a push recoil while light ones snap.
You just have to figure what works for you and what do you want to shot.
These are just my thoughts and experiences your may differ.
cheers
Allay
