Here is the situation with SAAMI for the 10mm it is not a ceiling at 37,500 but an average of the MAP(Maximum Average Pressure) testing.
This is based on 10 cartridge test and the MAP of that test is scored based on the results.
Manufactures are responsible because they can be held liable, people like Mudrush, DT, BB are trying to provide for a select market of custom ammo but they don't know your equipment or it's condition while using their products, even though they test using exact or simular pistols.
It is possible that brass manufactures are not being as consistant to the true pressure rating, thus casings being made thinner or which are softer and flow/shear easier. Different manufactures building for thier own cartridge specs could account for the stuff we are seeing.
I hear a lot of people say that StarLine is soft and they see bulging or smiles but atribute this to lack of support. Combination of both come to mind here!
I have seen Federal Brass as shot from MP-5 10's which exibit splits on the initial factory loading. This can be a result of the fluted chamber of the MP-5 and or the cartridge case being brittle as made by Federal.
As a handloader I am responsible for my own safety...that being said...
I select the componets I wish to assemble for a particular loading.
I setup my pistol with increased recoil springs and/or stock or aftermarket barrels for my situation.
I build my loadings and test to insure 100% function more than maximum velocity although a balance for both are possible, because I take time to test and evaluate my findings. It is not that loader "A" did this that I can duplicate exactly what he/she did and expect the exact same results or safety.
I use many already fired cases from many different manufactures and test loads using some of each, but attention and careful inspection are part of every aspect of quality control on my part! I do throw away many rejected cases that show problems at any stage of the loading process, doing them single stage yeilds many opertunities to visually inspect them at each step. While working near the edge of ballistic performance I hand weigh each and every charge as though they are match grade ammunition, but that's how I roll'em! Yes it is slower! But I have 100% cofidence in my work that equals a satisfaction that pays dividens in quality custom ammunition at reasonable cost to me.
To those who use or intend to use progressive presses...leave yourself some room for variances, as there are many operations happening at the same time. Know and understand your equipment, eliminate any and all distractions and stay focused on what is going on! The one that scares me is powder bridging...this is where powder sort of gets stuck in the powder drop and all of a sudden it comes loose into one case...can we say..."Oh Oh!" Big Bada Boom!
I will say if someone doesn't share the passion of handloding don't do it, but if you are willing to understand all the processes, understand the limitations and put forth the time and effort, you too can roll your own ammunition. Safely!
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Last edited by _The_Shadow; 06-20-2011 at 16:03..