1: What kind of powder do you suggest? (5.56 and 9x19)
The powder you would use for your rifle may be unique especially depending on your barrel twist and the bullets you will be shooting out of it. Since you mentioned XM193 a little further below, I am guessing you are having good luck with 55gr bullets. That will lead you the faster realm of rifle powders. The different companies who manufacture the powder offer suggestive information as to what would be more tailored to your personal needs.
I, in particular shoot AR15's with 1:7" twist barrels and exclusively 75gr+ bullets, which means I use a relatively 'slow' powder which is Reloader 15 from Alliant. But that is what I use in MY rifle, and does not mean that will be what you use in yours - on the contrary, you may be using a completely different recipe. Again, as has been suggested, you gotta do some reading to figure this kind of stuff out.
For 9mm, it will also depend on what you want to get from your reloads. Do you want velocity? Do you want soft shooting ammo? Do you care if the powder burns cleanly? What kind of bullet will you be shooting, lead, FMJ, HP, etc? What weight are those bullets going to be, 115, 124, 125, 130, 145, 147? What barrel length are you working with? Only your G19? These questions you have to answer before someone just gives you a powder to try.
I, personally, use Winchester 231 with 115gr bullets in my M&P9. I use a charge of 4.5 gr loaded to a OAL of 1.090 IIRC (at work, don't have access to my database). This cycles and shoots with wonderful accuracy in my gun, but may not even cycle your slide or may shoot horrible groups out of your G19.
2: How many times can one single casing be reloaded?
This again depends on how you reload them. Cases that are shot with lighter loads you can get more loadings out of then cases that have been given some hotter loads. How many depends on too many factors to give you any kind of definitive answer. I, personally, have shot cases that have been loaded over 10 times with no ill effects, but my loads for them are on the lighter side of the house. But with 9mm, it isn't really worth trying to stretch the limits due to cases not being hard to find nor expensive.
3: Can federal xm193 casings be reloaded?
Yes, but make sure that if they have a crimped primer pockets that you take the necessary steps to remove that crimp or you will ruin quite a few primers before you realize your error. If this makes no sense to you, you have to do some more research.
4: Can winchester white box reloaded? and if so, can i use a higher grain? They use 115 gr. i would like to load 124gr.
Absolutely, you could even put some of the heavier weight bullets in the +140gr range in there if you chose.
5: How do you get the spent primers out of the casing?
Usually, it is done in the same step as resizing with a pin that protrudes from the sizing die to push out the spent primer. Some people choose to deprime/prime sort of out of order/off press by using a seperate universal decapping die and then hand priming their cases with one of the many tools used for hand priming. This gives them more feel when it comes to seating primers which can lead to more reliability from their loads.
I, personally, do it all together on the press but that is what I have chosen to do and doesn't mean you have to do.
Just to cap this, you really have to read up no matter how boring you might think it will be. Believe it or not, when you are really into something, the reading actually doesn't become boring and becomes interesting as you process the information. And if you have read this far into this post, then you obviously can hack reading a couple pages out of a reloading manual or the ABC's of Reloading book
Good to have you on board and welcome to the next addiction in the shooting sports.
Damian
