S&W M&P 9mm Pistol
I’m dating myself if I use the phrase “just a silly millimeter longer” but it often occurred to me on this next case. I say case, because it was more of an investigation than a gunsmithing repair. The customer brought me his Smith and Wesson M&P 9 mm. His complaint was that the magazine had started falling out after his last range session. I started the usual questions – Did it happen all the time? Yes, every time. Do you have more than one mag? Yes, I have three, including a couple of extended capacity mags.
Does the problem occur with every mag? Yes
Forgive me for asking, but are you sure they are the right mags for your pistol? Yes, they are the right mags.
He left the pistol and I started going over it. I know this and knew he kept all of his tools in top notch condition. This care extended to his firearms. This pistol was in like new condition. He had attached a laser pointer under the barrel. It was held on by two hex-head screws. I could find nothing wrong with the pistol, or its operation except for the fact that the magazine catch would not engage the magazine. Every time I inserted it into the well, even empty, it would snag and then fall free.
Figure 2: M&P Magazine Catch
Removing the catch from the frame, I could find nothing wrong with it. There was very little wear. I did observe that the magazine did seem loose in the mag well. There seemed to be a millimeter’s play and that was enough to slip the mag. I had a .40 mag in the shop, and it fit and engaged perfectly.
I called the customer and explained the situation to him. I told him I didn’t see how, but it seemed as though someone had put a .40 call frame on his pistol.
“I’ll get back to you.”
A couple of days later, my customer called back wanting to know if he could come to the shop. He was bringing another customer with a .40 cal. M&P who had just discovered that it would not take .40 cal. mags any more.
The Rest of the Story
The M&P 40 was nearly as pristine as my customer’s 9mm. The only visual difference was the laser pointer mounted on the 9mm. Both gentlemen were convinced they had the correct frames because of the laser sight. That is when I found out the rest. It seems the two gentlemen had taken a couple of young men to range to teach them to shoot. It seemed to them that having nearly identical pistols, it would allow for a comparison of calibers and allow the young men to determine which they preferred. As a part of the teaching opportunity, the two young men were instructed on how to clean the pistols, but not, shall we say, monitored very closely.
The two young men stripped both pistols at the same time and cleaned them. Although there were no allen wrenches in the cleaning kits, they were able to remove the laser sight from the 9 mm and inadvertently swapped frames. The slides fit perfectly on either frame. Seeing the laser sight under the slide that said 9mm, neither of the gentlemen suspected a thing.
It took about 15 minutes to set the two pistols to rights and verify correct function – after I stopped laughing. I didn’t even charge them. I figured the story was worth it. There are some good lessons to be learned from this and I use them whenever I teach any firearms class:
- When cleaning multiple firearms, only clean one at a time. This is not the first time I’ve encountered this type of swap, and in some firearms it can create a dangerous loose breech problem as parts wear to the specific firearm and each is unique in wear pattern.
- If “teaching” someone else, closely monitor their work and double check everything.
- Check fit and function of every firearm as it is cleaned, before it goes to its storage.
- When a customer brings you a firearm for repair, knowing the malfunction is not enough. Far too often the cause of a malfunction resides outside the firearm. Take a moment to explore the context and background of the malfunction as well. An MD friend of mine says he does more diagnosis just taking a minute to talk with the patient, and they will often diagnose themselves.
Finally,
- Never assume something is mistake-proof. I have a little card posted on my shop wall reminding me “Nothing is fool-proof. Fools are ingenious.”
Ken Finley
