My agency (who had been in SIG Classic series since going to auto loaders in the early 90s; first .45 P220s then .40 P226s) decided about 2013ish to transition to a new gun. As senior Firearms Instructor I was tasked with this by the Sheriff and Major, and told to select a "committee" of officers from both sexes and different sizes and backgrounds. At the time the only guns we were given options on and had T&E samples of were the G22 .40 and the SIG P226 E2 Elite in .40. Since many officers carry Glocks off duty, me, the Sheriff, and the Major all assumed it would be the Glock. We had about 4 range sessions over different days, and presented the guns as unbiased and unweighted as we could (and even final votes were anonymous, however most folks openly shared their opinions). The G22 was the almost unanimous choice and I took this back to the Major. He is a good man but he is a big SIG guy (or was then) and he told me he wanted to "table" the test and decision until we could test the new P320 when it arrived.
We got two in on T&E and they ran like champs. Both guns fired at least 1200 rounds each, and were never cleaned. They were also more accurate for every officer than the P226 or the G22, given the awesome trigger. I was on the fence, and took one last magazine out to the 25 yard line, and with a witness I fired one round (granted, very slowly) and it cut the "X" in the dead center of the bullseye. We chose the P320, but it took a while to get 100 guns.
In the meantime, my brother-in-law in Georgia was looking to trade his well-worn G23 and called asking my advice. I told him about the P320 and how it had "wowed" all of our firearms instructors and deputies that shot it so he bought one in a store in GA. He called back a few days later and asked "Why do you hate me?" I was confused and he said that the P320 wouldn't even fire an entire magazine of anything but ball ammo, and would sometimes hiccup on that. He said he, nor even the staff at the range, could fire it without malfunctions. I told him it was obviously a lemon and how to go about sending it back to SIG. He did, and got it back two or three weeks later, with a list of changes (I think barrel and extractor?) He took it back to the range and STILL Had malfunctions. He AGAIN sent it to SIG. We still did not have any of our P320s, but I called our SIG rep and he said he would handle this. He "had the gun brought over to the law enforcement side" where he said he could better address it, and had a senior gunsmith handle it. My BIL got it back in a couple weeks and that thing never missed a beat. It fed anything you loaded in it. After my BILs unexpected death in 2015 I inherited this pistol and it was flawless.
We did get our agency guns in and began transition training, and all FIs were given free "Armorer" training on the P320 (we were all already SIG Classic Series armorers). During transition qualification, some guns did have malfunctions, but it didn't seem extreme...AT FIRST. After all, these were new guns fresh off the drawing board and I guess we figured we were Beta testers. MY gun never had a problem-I think it may have had a couple of "slow feeds" where I nudged the rear of the slide but that went away after 100 rounds. Others however were bad enough that the Major issued them another gun and took theirs to be inspected or sent back. We finally got through quals and were carrying them. Then I starting hearing the SWAT guys (far and away our highest round count shooters with monthly training and the annual SWAT competition) griping about them "jamming." The issues were across the board also-not one noteworthy problem. Different guns, or sometimes the SAME guns were Fail To Feed, Fail To Eject, Slow Feeds, and possibly a couple of Fail to Fires(?). SWAT guys running shields noted a higher number of problems as they shoot around the shield in a sideways cant ("gangster" cant in the movies.)
The guns affected were sent back to SIG and returned. Some indicated changes had been made, and some just said "Inspected-Found to be within specifications". The next spring during departmental quals, regular officers were experiencing malfunctions at a much higher rate than we had ever seen.
SIG then told us that our guns were victims of "tolerance stacking" and they would replace all our frames for us. We had to arrange for the entire department to come by the range while the reps were there which is HUGE headache, but then they gave enough to one of our FIs that he did the rest over several days. We STILL had problems. Then SIG replaced the BARRELS for us. Still, malfunctions continued.
In 2015 or 2015 we finally called SIG and the distributor and told them to come get every P320 we'd bought and the Major was a real hard butt on them and told them they had better give us the full value we had paid for them, and not to try and credit us with used prices.
By then, upper management, even higher than me (lieutenant/senior FI) had decided we were going to 9mm. We went to the G17 and I retired at the end of 2018. My department is immensely happy with them. There has only been one shooting and the 124 grain Gold Dot dropped the BG like a rifle.
