Having an original 4006. A Sig 229 and a Shield all in 40 For many years. I say your blow up worries are unfounded.

BTW. When I bought my 4006. No 40 Ammo was available. The gun and caliber were brand new. I got one box with the gun. I trimmed and inside neck reamed 10mm cases for a long time. They shot well.

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S&W Accumulator