O.K., after some consideration of what I would be doing with the modification suggested here, I decided to ask S.A. Customer Support for a new takedown tool with a smaller diameter wire that would fit the opening in the guide rod. I did this because this EMP4 was purchased as an EDC and I am barely comfortable with a 1911 for this purpose, so I don't want to mess with something I don't fully understand that might affect its performance. So far, I've only put 50 rounds of Remington 115gr FMJ through the gun, because I don't have the ammunition for more. It was able to feed all the rounds without any problems and that was reassuring, but it's far from a final judgement on reliability. If you have more experience with your 40 S&W, I'd be happy to hear it, but for now, I'd rather put a few hundred more rounds of 124gr through the 9mm to decide if I really want to carry it. Thanks again for your time in putting in the post.