I took the new P320 X5 full-size to the range for the first time after cleaning and oiling. I had consistent failures to eject. It happened every 3 or 4 shots with all of the mags. Ejection was weak and nearly straight up on the rounds that did eject. I only had two types of ammo with me, Freedom Munitions 115gr FMJ and Remington Green/White box 115gr FMJ. These are not the hottest rounds for sure, but they've run in all of my 9mm pistols, including the other P320s. I've never had trouble with either of these ammo choices in any gun. The range was sold out of 9mm, so I couldn't experiment right then, but I plan to test out the gun with some Geco FMJ that should be here in a few days. Geco is usually pretty hot. I also have a Gray Guns Fat guide rod on the way and will experiment with some different 1911 spring weights. Any other ideas? I'll obviously call Sig if it keeps happening after I get some more rounds through it with different ammo. I love the gun though.

I had multiple failures with 115gr. initially. I switched to 124 and have had zero failures. And I suspect when I go back to 115 after running 1000 124's through it I won't have any more. Keep in mind this is a competition gun with very tight tolerances and is a bit oversprung. I had a conversation with Yong Lee (you can youtube him) and he mentioned it's over sprung. You can switch the spring and guiderod or cut coils off of the one it came with. I have two, one with the different guiderod and 1911 spring and the "gen 2" version which is completely stock. Both run great but there's nothing wrong with the gun, but the spring is tight and requires either hotter ammo or a break in period to reliably shoot weaker ammo.

Have not had that happen at all with mine.

Cleaned and greased it up, and ~1,000 rounds of 124 gr 9mm later, no issues. All GECO and Aguila factory FMJ so far.

I did put in the GrayGuns guide rod right off the bat though.

I have shot a bunch of 115gr with no issues. The rounds I've used are Blazer Brass, Fiocchi, and American Eagle.

Before sending it back I would try another brand of ammo. Like you said, those two are definitely not very hot.

Are the cases a little swelled toward the rim, or is that just the light/angle of the shots?

quote:

Originally posted by jljones:
Are the cases a little swelled toward the rim, or is that just the light/angle of the shots?

I think it's just the light. I didn't notice anything unusual about the cases. I'll look closer next time out and have more ammo choices with me.

The reloads shown in your images appear as exhibiting excessive base expansion and improper resizing. This is not proper, factory ammo. Such ammo cannot be expected to function reliably.

I’d recommend trying the 15X ISMI recoil spring with some first-quality 124 grain factory ammo to start, and work from there. If you want to try some Lucas lubricant, let us know? Good luck!

-Bruce

quote:

Originally posted by Grayguns:
The reloads shown in your images appear as exhibiting excessive base expansion and improper resizing. This is not proper, factory ammo. Such ammo cannot be expected to function reliably.

I’d recommend trying the 15X ISMI recoil spring with some first-quality 124 grain factory ammo to start, and work from there. If you want to try some Lucas lubricant, let us know? Good luck!

-Bruce

I'll take it out again when the guide rod and spring arrives. I have a few different 124 grain ammo choices on hand and more on the way. I'm all set with Lucas gun oil and grease. Thanks!

quote:

The reloads shown in your images appear as exhibiting excessive base expansion and improper resizing

Resizing may be checked with a gauge; or remove the barrel, drop the cartridge in the chamber, & feel if properly seated. Then turn the barrel upside down & the cartridge should just fall out

guide rod, with 13# spring should take care of your issue.
Also, with the stock spring, if you watch your front sight, it dipps when the slide slams forward.
WAY to oversprung for normal loads, but, if you plan to shoot hot stuff like +P+, or, Winchester NATO, stay with the stock recoil spring assembly

My new 320 X-Five also had the same problem and I was using 2 different brands of 145 grain ammo. My slide would not stay locked open on the last shot/last round in the magazine. I sent mine back. Sig emailed me this weekend that they will be sending me a new 320 X-Five....so it may be worth talking to them.