I would also recommend joining the Fifty Caliber Shooters Association. THis is the very best source for information on the big 50 cal round.
As far as loading componants, it all depends on what you want to do.
I read one of the posts that said all 50 BMG shooters use Military surplus brass. Well, I know alot of 50 cal BR shooters and hardly any of them use surplus brass for their match cases.
If you want to load plinking ammo, thats one thing but brass for the BMG is just like brass for any other rifle, there is good brass and bad brass. I have always used PMC brass until recently when I have switched to IMI and now with that becoming hard to get I will give the Magtech brass a try and see how it does.
The problem with Surpus brass is that it is often mixed and you will have to sort it out. Also, if its once fired, it has been fired in an M2 Browning heavy machine gun and in most cases the chamber specs are not all that tight in the browning. Also, if the headspace is not set up properly by the gun crew, the cases will be stretched just ahead of the case head.
Now if your like most of the other 50 cal shooters I know that drop $3K on their rifles at least, they do not want to take the chance of finding a case with a thinned case head and have a problem when they load it.
If you get unfired surplus brass that is a different story but then you have to deal with removing the sealer in the neck of the round and that can also be a pain in the rear!! You also have to remove the primer crimp on the mil cases which is not hard to do but there is no need if you just buy commercial 50 BMG brass.
The thing about 50 BMGs is that if they are loaded properly you will not go much over 50K psi in chamber pressure. The best way to check your loads pressure is to shoot a round and extract the case, then put that same case back in the rifle and close the bolt on it in the chamber. It should chamber easily with no real resistance. If you can not rechamber that fired case or you have to lean on the bolt, you are loading your rifle to hot.
Loaded this way , you will really never wear out a batch of 50 BMG brass so there is no need to skimp on brass prices, get some good stuff. Also, you will have a single shot rifle with the M99 so even 50 rounds is alot. I would dare say unless you have a group of shooters shooting your rifle, you will not put 50 rounds of ammo through your rifle in on day of shooting unless your shooting comp at a FCSA match.
I tell my customers not to go overboard with brass, get 100 rounds for a single shot, 200-300 for a big semi auto and that is plenty.
If you want to load lower priced ammo, save your money on bullets and powder but realize that accuracy will suffer as well. Most of the military surplus bullets can be had for very little price. The last batch of 700 gr FMJBTs I bought came in a 250 round pack for $60. Thats pretty darn cheap.
One thing to watch for is loose cores though. I go through all my surplus bullets and shake each one. You can actually hear the cores rattle on some of these bullets. Those that do get culled out and used for either velocity testing or just as plinkers for someone that wants to give the big 50 cal a try sometime.
Sorted bullets are actually pretty accurate generally holding around 1.5 moa at 1000 yards if sorted. This is not great but for the price of the bullets its very good and generally more then enough for causal rock busting.
Powder is where you will save alot of money if you want to load cheap ammo. Surplus pulled ammo is very cheap but you buy at a risk of getting low quality powder. Powders such as WC872 is also very low price and you can get this powder new that has not been pulled down and get very good results with reasonable price.
Again, do not figure brass costs into your ammo cost, the cases will probably last you the life of the rifle so after a few firings, its cost is already reduced to pretty much nothing.
Now for accuracy work, this is a totally differnet story. Just like any long range rifle, what you put into it will determine what you get out of it.
You will need match grade bullets, the A-Max is the most common and easiest to get. Wildcat Bullets makes some good 50 cal bullets as well as does Barnes with their new non-bore riding solids.
For match 50 BMG loads I have only used H-50BMG and have never had a reason to look for another powder as it is perfect for the big BMG. Most 50 BMG rifles loaded with a 750 gr A-Max will use around 205 to 215 gr of H-50BMG. If you load to the top charge listed on the bottle of H-50BMG which is 233.0 gr you will have a VERY high pressure load. This data is for a M2 rifle with a very loose chamber and throat.
Your rifle will have a match throat or at least a throat MUCH tighter then any M2. As a result pressures will jump much more quickly. Most start with 195 gr of H-50BMG under the A-Max and work up from there using the same rechamber the fired case technique to get a read on pressures.
Most accuracy loads with the A-Max will be in the 2400-2550 fps range. Some will push them to 2600 fps but not many that are really after extreme accuracy. The reason is not that the bullet will not handle the added velocity, the reason is because the recoil level increases dramatically with the 50 BMG with this bullet weight as velocity increases.
Primer wise, I have only used CCI-35 primers. I will tell you that if you get some primers, by them by the 500 brick or more if you can afford it. At times it seems there are primers all over available to the handloader, at other times you will go 6 months and not be able to find any of them, keep stocked up with primers, I keep a brick of 500 on the shelf at all times at least!!
If you want to shoot surplus ammo, I really would recommend you get joined up with the FCSA as they are a wealth of knowledge about surplus ammo and what is good and what is bad.
YOu do not want to run some corrosive surplus ammo through your find rifle!!!
Anyway, good luck with your big 50 cal, you will have alot of fun with it!!
Kirby Allen(50)