Hey yall. Back in December, I decided to try the P320 Carry, my first and only Sig. I fell in love with the gun, it is accurate and easy for me to shoot well. I shoot quite a bit of steel case 9mm, and have quite a bit on hand. I expect any handgun I own to be able to shoot it in an emergency and at the range. The P320 ran the steel case at first, but over the last few months, it has began to completely choke on steel. Although I ensured the extractor and it's components were consistently cleaned, the P320 no chokes on every other round of steel and fails to extractor every time. I installed a Lone Wolf extractor hoping this might solve the issue, but it did not. I also ordered completely new extractor parts from Sig to replace them all, but decided I no longer trust this gun with my life and do not believe sending it back to Sig would solve anything, as they will only tell me not to run steel.

As a result, I made the choice to go back to an M&P, as the GEN 1 and 2.0 I've had over the years never malfunctioned with any type of ammo I ran through them. I now have a M&P9 2.0 FDE with the Truglo FTX sights on the way and plan to provide a complete range report.

Plenty of people shoot steel through their 320s without issue. Perhaps you should ask in a Sig specific forum. I have a 320 Compact, a few M&Ps and other striker pistols. I never run steel in any of them.

Nice pickup on your new M&P and Welcome.

I have attempted to diagnose the problem with other Sig owners, and none can offer any insight other than don't feed it cheap ammo. That argument does not hold water with me. I understand that steel case ammo is looked at as been lower quality and in the past maybe it was. I have shot case after case of the stuff and have seen good accuracy and reliability with it out of Glocks, M&Ps, Rugers, and even SCCY handguns; some people believe it is dirtier than other types of ammo, but I personally have not seen that. When I have to pry a stuck casing out of a handgun with a reputation like Sig, something is wrong. Some people may be able to live with the fact that their gun runs fine only with brass or they only intend to feed it with brass, but if I need to use any kind of ammo in an emergency, I want to be able to depend on my gun cycling that ammo.

Steel based shells whether handgun or shotgun can and do create cycling problems! The trapshooting forums report lots of extraction problems with steel based shotgun shells and I can testify I have, too. Apparently, steel cases expand and/or corrode barrel chambers in such a way that they cause cycling/extraction problems. Loose/oversize chambers seem to tolerate steel cases better for the most part. Polishing and/or lightly honing out troublesome chambers seems to help.

I don't shoot steel case in anything. I don't shoot aluminum in anything either for that matter.

You only run cheapest gas in your car or motorcycle? We aren't just talking about price here.

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ΜΟΛΩΝ ΛΑΒΕ

I've never had any vehicle I've ever owned break down from 87 octane, but then again I've never owned a Cadillac. I wouldn't call the P320 a Cadillac needing high test, just a combat handgun that should feed within reason anything that is SAAMI spec or factory built ammo.

I shoot A LOT of SCA thru my P320 without a hiccup. And, it's only 3 months old. You should send it back to SIG and see what the problem is. It can't hurt anything.
As a matter of fact, I shoot SCA thru my Rugers, Glocks, S&W's, etc. And, I have no problems with it in ANY of them. I even shoot SCA thru my AR-15's. SCA is no dirtier than any other brass ammo.

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How many guns are too many?

I initially intended to send it back to Sig, but I read an article reviewing the P320 Carry and their test gun wouldn't run steel out of the box. Here is the article: Sig Sauer P320 Review and Dirt Test [2019]

I contacted the author of the article and asked if they ever contacted Sig about the matter. He said he was told that the official company stance was not to use steel in their guns.

Georgian, I realize that some U.S. ammo manufacturers are introducing steel case ammo, and that is most likely SAAMI spec, but I have read that ammo coming from Europe and the former Iron Bloc isn't.

From talk in the pits at various matches and numerous years at Camp Perry, much has been discussed about shooting steel cased ammo in our target rifles. What I have learned is that steel cased ammo requires it's own cleaning regiment much like corrosive ammo. Apparently the sealant on the bullets creates a severe "super glue" effect after repeated use of steel cased ammo, and contributes to the non-contracting steel cases not readily extracting from firearms. I would suspect that the chamber of your P320 has a significant build up of the case sealant that is causing your extraction problems.

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Judge control not gun control!

Why use steel case ammo and complain about the pistol? Use brass.

I have several firearms that were designed with steel case ammo in mind and zero experience SIGs, so take this for what it's worth. To me it sounds like you are getting varnish or other case coating/lubricant build up in the chamber. If one of my firearms was getting balky with steel case ammo the first thing I would do is thoroughly clean the chamber and barrel with carb cleaner and a good brush. Among other things carb cleaner is designed to help soften and remove varnish.

I once had an issue with some steel ammo in my P320. A friend of mine said he heard of the issue and advised me to dump the box of ammo on a piece of cardboard and put a few drops of gun oil in the rounds and roll them around. After I did that I didn't have anymore issues

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Shot placement is key!!

I do. I don't own any vehicles that won't reliably run on 87 octane.

Hmmmmm, interesting!

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How many guns are too many?

A lot of cars will run on lower octane gas, the knock sensor will cover your butt for a long time among other things. Guns don'thave those unfortunately. My point was, obviously, that when you run the cheapest junk you can get, it often affects performance. It doesn't have to be a Cadillac or high end sports car to need decent gas. Doesn't mean you have to put premium in it. I bet you wouldn't put old or gas with water in it just to save a few bucks, but often people do when they look for the absolute cheapest gas around.

A lot of people use cheaper ammo in their pistols, you can get factory new brass ammo pretty cheap. Even that has issues sometimes, far more rarely in the scope of how many use it, but sometimes. Steel ammo is probably the cheapest stuff you can buy, pretty dirty too. Some guns run it and some not so well.

Brass is literally a few cents more per round, but its your gun, so run whatever you want, if itll run it.

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By the way, the Sig 320 X Carry has a Match barrel.

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ΜΟΛΩΝ ΛΑΒΕ

Georgian, you say you don't trust the Sig, but you aren't going to be using steel case as carry/self defense ammo are you ?
You just run it for practice/range ammo ?

I used to avoid steel in my rifles but have eased up on my dislike of it.
I run the better brands of steel along with some brass as well.
Never had the desire to run it in handguns though.
Rifles have a lot more extraction power than handguns, so are less likely to have problems extracting steel.

I think Old Goat hit upon the problem when he talked about tighter chambers being the cause of extraction problems.
Steel doesn't contract as much as brass during that millisecond after firing. Brass does better as it expands to seal the chamber, then shrinks after the bullet and powder gases have left the barrel, making extraction easier. Using steel case ammo can also be harder on your extractor because of it's poor contraction properties.

It sounds like you have a tight chamber, polishing it with a Flex-Hone brush and Flex-Hone oil will help. A cheaper alternative than Flex-Hone would be to put some polishing compound like Flitz on a bore mop and chuck the mop in a drill.

I doubt that steel case residue is the problem but it wouldn't hurt to clean the chamber well also. There were problems in the past of lacquer used on steel case ammo depositing in the chamber, but that was more of an issue of guys doing mag dumps in rifles using higher intensity cartridges.
.45 Auto is a low pressure cartridge, and they just don't get that hot when fired compared to 5.56mm, or even 7.62 x 39mm.

Steel case ammo needs some type of coating to prevent the steel from corroding easily.
Most all Russian manufactures gave up on the lacquer and switched to a polymer coating some years back which eliminated coatings getting deposited in chambers.

Is this extraction issue in your P320 just with one brand of steel case ammo ?
If so you could try other brands.

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U. S. Army Veteran

That could compound the extraction issues. Why would a manufacturer put a match barrel with a tighter chamber on a carry/defensive pistol ?

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U. S. Army Veteran

Yes, sandog has excellent comments on this issue! Dare I say that lots of trapshooters have noted that steel based hulls expand on firing and do NOT retract in some rather tight chambers on some shotguns (Ljutic for one example). Cleaning, polishing, and light honing of tighter than normal chambers seems to help.

If it worked with steel ammo at first and now it doesn't, I suspect the chamber is cruded up with residue that the steel cased ammo leaves. Does it work now with brass cased ammo?

I have seen this issue many times. What I believe to be happening is an issue with chamber size. This happens in shotguns a lot.

People often say that brand X won't work with steel. I'm not convinced that's true. What I think is happening has to do with tolerances.

Chambers are built to a particular diameter. In the case of the 9mm, I believe it's .389" diameter. However, nothing is absolute and the chamber can be larger than that. If it is, the casing might not rebound as expected after firing and this can cause sticking.

So, it is possible that it's a barrel issue and SIG will fix it. Give them a call and see what they say.

Even so, I'm glad you like your M&P.

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Freedom isn't free.

I would never run steel ammunition through a pistol that I either needed to function 100% in a self defence situation or a competition. I have seen way to many extractors breake because of the steel casing. But I am very interested to hear how the M&P will handle long time use of steel ammunition.

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Hello darknes my old friend

This fella has allegedly put 4,000 rounds, majority of which he says was steel case through his 2.0 5inch.
YouTube

So, according to your posts you are willing to consult internet boards, "expert" friends, authors of articles, and even some "fella".
However you are unwilling to contact Sig?

To each his own , as they say.
In my case , if any given action was causing undesirable results , I would eliminate the given action.
Thats just me...
No need to over analyze

I own an MP 9mm that I bought back in 2007. I have shot thousands of SCA thru it, from new up until just recently, and NEVER had one hiccup!

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How many guns are too many?

I've never had any issues using steel, brass or aluminum.
If SIG really made that statement then that would be the last SIG I would ever purchase.
Gun manufacturers are too lazy nowadays to make sure their guns are reliable so they just throw out a BS excuse hoping we accept their answer.
I'd send it back and make them fix it.
Anyone remember back when they'd send you the spent casings from test firing? I still have some and a few are steel cased So?

I'm not a fan of steel case ammo. I admit it. However, when one is talking about a combat firearm, the inability to use any round that is properly made in terms of dimensions, projectile, and powder is not even close to acceptable. Period. Given the well documented problems with the Sig 320 after its adoption by the Army, I would not get one under any circumstances. This is just another reason to not have one.

I have had more than one Sig. I still have a 239 9mm, which does not get used much. Given the history of crummy QC at Sig for the last 15 or so years (heavily discussed on a couple of fora and not really open to question), and my own experiences and perceptions (I ordered one a few years ago that was so bad when it came in the dealer rejected it), I would not own one. Anyone can make a lemon - look at the (relatively few) folks who have trouble with their Smiths and report that here, or the terrible problems with the Glock 22/23 along with some rare problems with their other models - but Sig is simply a no go.

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NHI, 10-8.

I recently came back to S&W M&P after about 11 years. About 4 firearms between 2 manufacturers and I'm settled on the 2.0 compact FDE 9mm with the 4" barrel (style 12458). Can't believe the changes since the 2008 M&P and the trigger is so much better.

The OP's first post was that he wanted to use any correct caliber he could find. The discussion about not using x,y, or z is irrelevant to him. It simply doesn't help him. I think of it like the rimfire guns that say don't dry fire. I don't dry fire them cause I won't buy them.

SIG says don't shoot steel case, fine I won't buy SIG. I have no problem with good correct maintenance as needed for the combination.

I have lived in areas where ammo choices weren't very varied at times before Amazon, etc.

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SWCA 3417 HF 642 NRA-TC

Good choice, OP. Make sure and give us that range report.
I like my 5" FDE MP9, the only thing I've ever shot better with were some high dollar 1911s.
I put Apex trigger parts and Tru-Glo sights on right away, this is the day after I got it, and it already has the Apex trigger and parts and TFOs.

Here it is at the range with my Mini-30 I Cerakoted in FDE (and Desert Sand).

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U. S. Army Veteran

Well here she is (range report to follow later in the week):

Looks good, Georgian ! I see it already has the Tru-Glo sights.
My MP9 is dead on with 115 grain loads, 124's aren't bad, just a tad high.

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U. S. Army Veteran

Well first range trip down. I put about 350 rounds through my new M&P today, without a single malfunction. I ran 200 rounds of brass FMJ through the handgun first (100 S&B 115gr and 100 Fiocchi 115gr), followed by 100 rounds of Tulammo. The handgun was only allowed to cool long enough to reload my five magazines, and first again. The sights are sighted for a combat sight picture, which I prefer. The first picture shows groups I fired at 15 yards. The top group was the first group I fired with Hornady 135gr Critical Duty. I probably could do better, given I was still learning whether it was sighted for a six o'clock or combat sight picture. The group directly below that was with the S&B and the right group was Fiocchi. The second picture shows a group shot at ten yard off hand with one of the brass FMJ loads. The trigger on this 2.0 is a very good factory trigger, with a short crisp break and short reset. The handgun is everything I expected it would be. All casing were ejected in a nice pattern 6-12 feet to my 3-4 o'clock.

Me too! I run cheap gas and cheap ammo. call me weird!

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S&W BG380, S&W 915 9mm

I split 1k case of steel for range ammo with my grandson. We’ve been doing that for 2 years. Never an issue. Thousands of rounds & my M&P 2.0 hasn't had a single problem.