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Jon,
I see looking at your post that I misprinted the bronze alloy in my post. It should be 932. I've been typing in a dark room and can't seem to keep my numbers straight. . .
I bought some short pieces of 932 from McMaster Carr in chicago. The prices were not as good as the local metal supplier if I bought larger quantities but for test batches they aren't bad. 260 brass is also good. Its known as Cartridge brass because thats the original and primary use for it. Its machineability is not as good as 360 but most of us would never notice.
At first glance I would say expansion on this type of bullet is a dream but the reality I found with the .50 cal and 20mm projos showed me different. At higher velocity even the solids expand well in sand but I don't know about subsonics expanding at all even with huge hollowpoints. I don't know about the grooving either. I would think that deep enough grooves to make a difference might promote splitting due to the spin rate in some of these bullets. I have seen some solids explode but they were sintered bronze known most often as oil-lite which is used for bearing material. Some guys like it to make projos for the small cannons because this stuff will leave a smoke trace out a few hundred yards due to the oil impregnated in it.
Maybe this won't apply to the much smaller diameter bullets you are looking at.....
Frank
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