I picked up a previously owned MK40 last week and it runs great. The previous owner had installed a stainless steel guide rod assembly. After putting 200 rounds down range I noticed the guide rod was protruding about 3/8” past the front of the slide. It had been just slightly ( maybe 1/32”) past the end when I starting shooting. I disassembled and could find nothing wrong. Reassembled,still protruding. Has anyone had this happen? It still functions perfect! Any help would be much appreciated. Thanks Sears