Lest we forget, one TFLer took his P220 to a "reputable" smith in TX. The 220 went full auto, cracked the frame and had to be sent back to Sig. To their credit, while the damage was not attributable to the gun or its design, nor was there any liability on their part, Sig replaced the pistol for free. Lesson: Be careful and go slow. George gave some good advice. Stick to it.
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Vigilantibus et non dormientibus jura subveniunt