Hello- real quick, I have a P320 that I converted from the full-size to a carry configuration for duty carry. The issue I'm having is the following:
1. Insert full (17 rounds) mag into pistol
2. Rack the slide to put one in the pipe; very difficult to rack the slide with a full mag
3. Drop mag and insert one more round to top off mag
4. Fire, slide does not come back to eject or feed a new round. Have to eject the spent round from the chamber. Sometimes it stove pipes.
5. Experimented with all 7 (17 round) mags; each one does the same as above.
6. Insert a full mag; rack the slide and let it operate with only 16 rounds in the mag- works fine.
7. Both 21 round mags function as should, no issues when fully loaded and topped off after putting one in the pipe.

I've used all sorts of different ammo- factory 115, 124, 147; FMJs, JHPs, & GDHPs with the above described failure. Reloads of the same weight created the same issue.

Approximately 400+ rounds have gone through the pistol. Could it be the recoil spring still needs breaking in? I've stored the mags with rounds in it for weeks hoping to break in the spring set of the mags.

Pistol has already been to the Sig factory for a once over replacing the extractor and extractor spring. The factory declared it G2G using 50 factory 124 gr. FMJs. Pistol never did act this way when I had it in the full-size configuration. I like the more compact carry version for duty carry, that's why I'm not converting it back to the full-size.

Hoping to hear from some that have a P320 with similar or no issues at all. Thanks, CJ

Hi! We've sern this before. Certain 17 round mags are just really tight. When fully loaded, the tension exerted by the top round is sufficient to retard slide movement during unlocking, thus stalling the slide. I had that same issue with some of mine. So, I loaded up each mag with 17 dummies, then pushed in on the top round by forcing it against the edge of my bench to break 'em in. . You'd be suprised at how much difference a tiny bit of "relaxation" of the mag body can make. The goal is not to kill the spring. I hope this helps?

-Bruce

Mr. Gray- I'm honored to have you respond to my post. Last week I spoke to one of your gunsmiths about this very issue. He recommended that I mark all of the mags and try each one individually in an effort to rule out bad mags. Well all seven of them did exactly as I described in my post. I'll give your solution a try. Sounds like the mags are the culprit after all. I guess this explains the reason the 21-rounder mags work well because the spring isn't as tight as the 17-rounders.

Mine had trouble with the first round in a full 17 round magazine when new. The springs will break in with use and it will go away. Just leaving them loaded doesn't quite do it. Bruce's advise to compress the fully loaded mag works well. My personal solution was to load the magazines, shoot them dry, and repeat.

quote:

Originally posted by copaup:
Mine had trouble with the first round in a full 17 round magazine when new. The springs will break in with use and it will go away. Just leaving them loaded doesn't quite do it. Bruce's advise to compress the fully loaded mag works well. My personal solution was to load the magazines, shoot them dry, and repeat.

Thank you for the advice, sir. I will do just that. However, I can say that I'm disappointed in this particular Sig pistol. I've carried Sig pistols for over 20 years in my LEO career and never had as much as a bobble with them. I'm still willing to give this one a chance. Thank you, again.

Is it really a problem with the gun? If you load 17 rounds it works just fine, is that correct? But if you load 17 plus 1 it doesn't work. Does it work if you are shooting and load a 17 round mag before the gun runs dry? If you reload? If it functions fine with 17, but not 17 plus one then in my opinion it works as advertised, unless you reload before empty and then it jams, that would be an issue for me.

quote:

Originally posted by JonFrost:
Is it really a problem with the gun? If you load 17 rounds it works just fine, is that correct? But if you load 17 plus 1 it doesn't work. Does it work if you are shooting and load a 17 round mag before the gun runs dry? If you reload? If it functions fine with 17, but not 17 plus one then in my opinion it works as advertised, unless you reload before empty and then it jams, that would be an issue for me.

JonFrost- I'm not sure if I understand all of your questions. I was hoping that I made myself clear in my OP. If loading a 17 round mag and then charging the pistol, thus 16 rounds and one in the pipe, it works fine. 17 +1, it does not. I do not understand how you can say it works as advertised. If you're referring to a tactical reload, I haven't worked it to that point. I'm still trying to get it to work with an initial load of 17 +1 in the pipe. For all of my years in LE, that is the way we carried. That is the way I expect this pistol to operate. It is my duty weapon and I don't feel like I can trust it at this point. So to answer your initial question, I'm still trying to determine if it's the pistol or the magazine. I'll side with Mr. Bruce Gray's above comment as he's had a ton more experience with this pistol than I have.

Okay, a comment made on another forum regarding this issue pointed to the different loading ramps under the slides. I'm led to believe the Gen 1 slides had a steep loading ramp vs. the Gen 2 that had a more flattened ramp. I took a picture of the two slides. It would make sense now that the slide without the flattened loading ramp can put undue stress on the top round in the magazine and push up against the bottom of the slide to retard it's movement. I wonder why the Sig factory didn't point this out or say something about it?

It will break in after a few loading and unloading cycles. You think the 320 springs are tough, try to load nine rounds into a new 9 round Glock 30 mag sometime. Pretty sure that was one of the Trials of Hercules. 10 round mags were perfect, but those flush 9 round mags... those took forever to break in enough that the first round would feed smoothly. It's a side effect of cramming every last round possible into a magazine of a set length.

Having the same problem with a compact 320 using sc grip module and 15 round mag. Worked fine with the 15 round mag and compact grip module and works fine with the sc grip module and the 12 round sc mag or the 21 round mag.

Someone suggested that the 17 rd mag have two versions of springs. One is longer. I wonder if it is the size kf the 21 rd mag.
That would cause a stacking issue and a fully compressed spring with less room in the mag body.

I have some 17 round mags that will not accept 17 rounds no matter how hard I try. I have left them loaded with 16 rounds for months, unloaded and loaded them a bunch of times, but there is no way they are going to take 17.

quote:

Originally posted by cjklekar:I wonder why the Sig factory didn't point this out or say something about it?

Because they prefer people didn't know about it.

I found a fix for this problem. The problem is the magazine marked "made in USA" will not work as a 17 + 1, however the "Made in Italy" will. I took a mec-gar magazine (marked made in Italy) apart and a checkmate magazine (marked made in USA) apart and exchanged the guts. The checkmate magazine now suddenly worked. I examined all the parts and the difference was the plastic insert riding the bottom of the spring, and above the floor plate. The non-working checkmate magazine has a tab on the insert that fits in a slot at the front of the magazine. The mec-gar that functions correctly does not. I dremeled off the tab and assembled the magazine and it functions fine as a 17 + 1 just like the mec-gar does.

Austin- I appreciate the note about the fix. I thought all of the mags were made by Sig and not Mec-Gar. I'll double check my mags to see what's what. I'm not clear on the 'checkmate magazine'. Further, I'm so disappointed with this pistol; I'm going to probably sell if after it gets returned from its trip to the factory for the 'voluntary upgrade'. I'm switching over to a S&W M&P M2.0 pistol for duty work. Sig has left me disappointed...

The American say Sig Sauer on the baseplate and the Italian have the circle Sig logo. I am pretty sure you have the American. It should say Made in USA on the side where it has the witness holes. If you depress the round peg in the baseplate and put your thumb over it you can push it off. Look at the insert, the flat piece at the bottom of the spring, and you will see a tab that fits in a shelf on the front bottom of the magazine. Just lop it off and sand it round to match the rest of the contour. Reassemble and your in business. Seven mags make take you a half hour with a dremel. I just got my 320 last week. The mags that came with it were American and additional mags I purchased were Italian. Both companies are OEM providers to Sig. It just came to me today to disassemble them and see what the difference was. Sorry your disappointed. I actually like the way it shoots for me and the modularity. But it does look funky. Hope it works out for you. Let me know if you need any other help.