For buying reloading components, the best place to go is Grafs. Very well organized website and look carefully at the bullets that they sell as "Grafs brand", they are usually blemished batches from very good manufacturers. There may only be a handful of bullets in the batch that are blemished when you buy 500 and usually you will be able to spot them and separate them out.
With the recent run on ammo and then a couple of weeks later on all reloading supplies, one of the items that has been hard to find has been primers. Always look for primers and powder in your local stores, since you pay a $27 hazmat fee when you order primers or powder online and have it shipped. Because of the hazmat shipping, the shipment of your order is also usually delayed and ends up going UPS ground. If your local store comes up empty of powder and primers (mine were in a 30-40 mile radius) then for powder and primers specifically go to powder valley inc. There you have to make a bulk purchase to spread the hazmat fee over several items. So for instance you can buy 5000 primers and 2 8lb jugs of powder that you need. Perhaps some Blackhorn 209 at the same time if you shoot a muzzle loader. Of course to nuy primers and powder in bulk, you either need to know what your load will be or have high confidence that it is going to work out for you since an 8lb jug of powder is typically running $142 and up and 5000 primers will be about $135+.
There are certain powders that are very versatile, which work for a wide range of applications. For instance, Hodgdon Varget is an excellent powder for 223, 308, and 30-06 cartridges. The suitability of a powder depends of course on the burn rate of the powder compared to the velocity of the load you are after. So if you are looking for 4000fps 22-250 loads, your powders will not be very versatile because they will need to be fast. But if shooting heavier bullets at milder speeds, one will find that generally the powders are useable across many cartridges. I do not have any magnum calibers, but they tend to favor the slower burning powders since they have big cartridges that contain a lot of powder and generally shoot down a longer barrel.
I got lucky and bought some Hodgdon H100V powder and so far it has worked great in my 243 Ackley Improved barrel with 95 and 105gr Berger VLD's. It is also one of the fastest powders listed for the maximum weight 6.5mm bullets for my 6.5x284, but I cannot tell you success stories since I am still waiting on my barrel...
For cartridges that contain a fair amount of powder, stick type powders are generally recommended since they are reported to be less temperature sensitive, whereas flake powders are known to develop higher pressure in hot conditions than when cold. This again may not be an issue at 100 yards on a deer size target, but it all counts when shooting out 400+ yards. The main thing which 1 poster has alluded to previously, is that stick powders do not feed accurately from a typical powder measure. For rifle rounds I have given up and set the powder measure to dispense about 0.5grain under the target load, dump it in the pan and weight it on the scale and then trickle in the balance until within 1/10th of a grain by hand. I hand weighed all the charges for my 500 round 308 batch and it still only took 2 evenings after work to do. I will probably be shooting that ammo for several years and the effort would have been worth it.
Something to keep in mind as a precision shooter is that it makes no sense pre-loading a huge stockpile of ammo. High performance rifles will typically wear out the throat of the barrel within 1000 to 1500 rounds. Basically the barrel will go once it has seen X lb of powder/flame. Some like the 222Rem and 308 will go a good long time (well over 5000 rounds) without substantial accuracy degradation. Others, like hot magnum calibers or overbore cartridges like the 6.5x284 or 243 Ackley may only go 1200 rounds before accuracy goes for a dive. During the 1200 rounds, one would have to constantly be adjusting the seating depth to "chase" the receding throat or else accuracy would drop off even faster.
I am not a competition shooter so have no need to shoot rapid strings of fire during a wind lull, so it may take me a good long time to wear out my 6.5x284, but I certainly take the life expectancy of my equipment into account when selecting a weapon to practice technique with. So for me, I will use the 223 to practice for up to my 243AI and the 308 or 8x57 to practice for heavier calibers, since both of these shooting a 175 or 200gr bullet respectively have a decent amount of recoil and require more attention to technique to get good repeatability than a low recoil/faster/flatter shooting caliber. There is more chance that the rifle will move under recoil before the bullet has left the muzzle.
If you buy good quality brass (lapua) and anneal after every 4 firings and adjust your sizing die to only size the absolute minimum needed, you should easily get 12 or more firings on the same brass. If you load maximum (or over maximum) charges, full length resize and bump the shoulder back every cycle, have rifle chambers at the maximum end of the specification, do not anneal, then you might have split cases after as few as 4 firings. Lack of annealing will also play havoc on neck tension to hold the bullet (brass work hardens) and that in turn will cause a bunch of fliers and lots of frustration.
I know that guys that go out and buy a semi auto rifle quickly figure out that one can burn through a lot of ammo really fast. But these are really not the ideal platforms for reloading. They typically require loose chambers for reliable function and are pretty brutal in the way they handle brass. The magazines, feed ramps, extractor, ejector and sometimes dust cover all leave their individual marks on the shell, not to mention the pavement, when it finally lands 6-15ft from the shooting position... The Cetme/H&K/PTR91 style rifles were generally made to fire steel cased ammo and certainly not made for leaving behind reloadable brass. Of all the weapons I have seen, they certainly come last for being reload friendly but that was never a consideration for their original military application.
I too had an AR style rifle and quickly tired of the way it treated my brass. The one I had was chambered in 7.62x39 and would not feed ammo very reliably anyway, so I got rid of it and went with an SKS and now shoot steel cased Golden tiger ammo through that and like it much better. For precision I have my bolt guns with their high quality ammo which of course stays in pristine condition as long as I do my part.
1 last thing to consider is to google "stainless tumbling media" instead of using corn cob/rice type media in a vibratory tumbler. I find the stainless tumbling media to give very good results and I don't run it nearly as long as the manufacturer says. 1 hour starting with a soak in *** water and detergent is more than enough for me and it cleans the primer pockets, flash holes, everything. The only thing to beware of is to not tumble different sizes of cases that can fit into each other. That can turn into a mess.