The neck doesnt "crush" if the die is adjusted right and they are lubericated properly.The 40% shoulder makes it easier to push the shoulder down if the die is allowed to hit it.When the die is set right the neck sizer till be about .010" above the shoulder.The way to set the die for this or any cartridge is to have it set up so it goes about 1/2to3/4 down to the shoulder and keep adjusting it down until it gets to the shoulder and keep trying the casing to see if it will chamber in your gun.Wipe the casing before trying to chamber and relubricate before putting it back in die.All belted mag,s. work better if you neck resize only.A neck resize die works best.You must keep checking to be sure they will chamber in your gun.You dont have to lubericate if using neck sizing die. sam.
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