Would it be safe with 650 gr to start of with 140 gr of IMR 4350 (AR2209)?
We are more interested in using the 650's and getting a little speed up, what is the highest velocity people have got there 650's going at ?
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However, to be extra safe I might bump it down to 130 grains to start with a new rifle, especially since I think you used a different barrel maker and reamer than me.
Be sure the case is not touching the lands before pulling the trigger.
what if I asked the smith to freebore our our barrels slightly to ensure the case will never touch the lands, is that possible??
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If there were pressure problems and a failure in a 585, it would likely be a catastrophic failure that causes injury, so be careful.