You can drive the 10mm 0.401" cast bullets as fast as the jacket pistol stuff if you use quality lube without leading. I use Rooster Lab's Red Zambini on mine with great results. The 156 grain Lyman Devastator HP id have driven to 1400 fps from the S&W 1006 5", slightly slower from the G-29 3.78".
I cast my own bullets for every caliber I load for and shoot other than rifles, gas checks really are not necessary in most instances for pistols unless driven above 1300 fps.
I use gas checks for some of my 30 cal, 357 mag and 44 mag rifle rounds as these are slighty above pistol velocities.
The other thing is finding a gas check mould...I believe SAECO has some but open your wallet wide! Then the cost of adding the gas checks (making them yourself) adds even more to the cost of shooting.
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