Re: 50 bmg
I have not used the LEE tooling in the 50 BMG but have with other chamberings. From that experience, there are some things that would make me think the LEE tooling would work but may not last as long as the Hornady or RCBS.
Between the RCBS and Hornady, the presses are pretty much the same, very similiar at least. I would say the Hornady seating die is a better choice then the RCBS as far as getting good bullet run outs.
Starting load, generally 210 grains of H-50BMG under the 750 gr A-Max seated 30 thou off the lands is a good place to start. Most load data for H-50BMG will say 233.0 gr is a max load, in my experience, this may be fine in a very loose chamber and throat of the M2 but in a single shot bolt gun, this is far to heavy of a load.
I have topped out at 220 to 225 grains in every rifle I have loaded for with this bullet.
TO check for proper pressure in the 50 BMG, there is a simple test you can do, shoot a round, eject the fired case. Take that same case and rechamber it, there should be no real difference in force needed to close the bolt on the fired case. If there is an increase in pressure, drop down a grain or two. If there is no increase in bolt closure pressure, you can increase the load by 2 grains and repeat the test, repeat until you feel the resistance when you rechamber the fired case.
The 50 BMG should be loaded to roughly 50,000 psi and no more. Cartridge brass will permanently deform at 50-55,000 psi in most 50 BMG brass. The big 50 is really far to large for what we want to do but when it was designed it was nessesary to be that large.
Many BR shooters will load to the 2500-2600 fps range for best accuracy. Not only are they more comfortable to shoot then the 2700 fps loads but these loads also produce milder vibration patterns then the upper end loads.
Your opinion of the military surplus ammos accuracy potential is right on the money but that is by design. WHen your shooting an M2 browning, you do not want precision, you want all those big projectiles to land in a relatively tight pattern but you want them to cover a decent amount of area at 1000 yards, like the better part of a truck!!! If several hits all over a vehicle, that will do far more damage then several shots in a several inch group on a vehicle.
We are using the 50 BMG for a much different use then it was designed for, precision shooting. It serves well in this role but you must realize it has to be loaded differently then surplus ammo to reach this level of accuracy.
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