Anyone make one larger than 200gr?
You could make them heavier but this adds more length to the projectile which occupies more powder space in the casing. The balance of weight to lenght for best peformance comes into play. The solid copper bullets like the Barnes bullets while they are light because of the copper only construction also occupy plenty of powder space.
In a perfect world a 200 grain Gold Dot would be a great bullet in 10mm, but they cater more to the 40S&W because of the popularity of that cartridge.
The ATF frowns :( on bullets being made with particular materials like depleted uranium...LOL The density would allow for more compact projectiles.
If you want an expanding bullet in larger than 200 grains, I would look to a gas checked cast bullet in a 220-230 grain config cast from 40:1 lead/tin. It should be plenty soft to expand nicely without a hollow cavity at the front. The gas check should minimize leading even from the soft alloy, provided it properly fits the bore and you use a good lube. And it should penetrate quite deep too.
At some point the bigger bullets will not stabilize correctly. The 215gr WFNGC cast bullet I have shoots great in my STI 6" and Caspian 6" but at what weight/length will we loose accuracy.
I did shoot a 255 gr WFNGC cast bullet in my STI at 10 yards. The cast bullet was from a 41 caliber mould I have ,I sized to .406 and then down to .401, worked pretty good. Velocity was in the 900 fps range with Blue Dot and AA7 and they would shoot 1" at 10 yards which really is not saying much , 10 yards is CLOSE . I did not shoot them at 25 ,50 yards to see if they held there accuracy or if they would keyhole at that distance.
Sean
My guns are all 1:16 twist as I recall. Based on the generic greenhill formula, I think you will run out of ANY case capacity for powder before you get a bullet long enough in a 10mm to have serious stability issues. This of course is general, and lots of specific circumstances can add a variable that will cause instability.
I guess my point is, with the 1:16 twist, we should be about to stabilize any reasonable length of bullet in 10mm auto.