Magazine capacity - new with gun 17 round exceeds Colorado limits

Hello All. I’m new to the gun world so please don’t assume I should know this. I’m on a steep learning curve right now.

I just bought my first handgun, a Sig Sauer P320. It came with two 17 round magazines. I live in Colorado which has a 15 round magazine limt. My question is ---- Do I need replace the two mags I have with 15 round mags to stay legal?

I don’t know when or where anyone would examine my magzines. I’m guessing it would only be if I have to interact with law enforcement or possibly in a training class. If it happens, am I legal since these came with the gun in the original box.



Welcome to the Community @Greg153. It’s great to have you with us.

I would suggest purchasing 15-round magazines, so you don’t find yourself in violation of the magazine limit in Colorado. I understand that it can be a pain, especially since the 17-round magazines came with the firearm, but this could keep you from having to deal with any unwanted attention or legal issues.

Here is a link directly to the 15-round magazines that are sold by Sig Sauer. If you are an active USCCA Member, be sure to utilize the available discount code that Sig Sauer offers, which can be located in your Member Dashboard, under the Perks & Discounts tab.


Welcome to the community @Greg153

Did you buy these from a licensed gun store? It is my understanding that it is illegal to sell or purchase magazines with more than a 15 round capacity in CO unless things changed recently. If you bought them from a licensed dealer I would ask if they can supply lower capacity mags or reducing plugs for the mags you have.

I have read that some sheriffs departments have said they won’t enforce this law but I wouldn’t count on that. The penalty for breaking this law includes jail time. If you ever need to defend yourself you want to make sure you have done everything by the book.


I agree with @Calvin_USCCA and @Shamrock . Get a couple 15 rd mags and use those. If you wish to keep the 17’s, that’s you, but I would make sure I’m 100% legal when carrying. If, god forbid, you had to defend yourself, idk how much USCCA could help you, since you’d be in the act of committing a crime by carrying illegal mags. If you’re not a member, and a self defense incident occurred, you may automatically have a partial loss because of the illegal mags.


@Greg153 Welcome to the community. I, too, have the same, at first I thought Co. was going to 10 rnd mag, so I bought 10 rnd mags for my Sig P320, Now they decided 15 rnd :+1: so I’m good with my 10 rnd mag, and so is my Sig P365 compact 10 rnd mags. BUT YES you SHOULD purchase the 15 rnd mags, stay LEGAL! Stay Safe! NM is pushing 10 round magazines with ongoing Legislation, AND “GUN REGISTRATION” if you want to keep what you have :worried: among other :poop: on the Bill they’re pushing that Will make Felons out of law-abiding citizens if these anti-gun bills pass.


I really hate to ask this, but here goes, what the heck do we do when they change it to a ONE ROUND magazine? And please don’t tell me it can’t happen, look where we are! How much rope are we going to give them?

Welcome aboard!

Me, I look to the future, better get your hands on 1 round magazines!
Why buy a gun to begin with, when they will be banned, take my word for it, by election season!

The W.H.O. is in charge and when the 2nd PLANDEMIC arrives, the constitution will be void, and by executive decree, Guns will be banned!
We’ve seen this movie, except in our case, NO ONE, NO CAVALRY is coming to save us! We haven’t done anything up to this point what makes anyone think we’re going to do anything when it gets worse and worse.

If you’re serious about saving lives, keep your 17 round mags and move to a free country, I hear Florida is still a free country!


I also live in Colorado and have found that some gun shops enforce the magazine capacity limits and others do not. I bought 30 round AR magazines at a gun show in Colorado Springs where the vendors had piles of them for sale. I walked out of the gun show past 2 uniformed CS PD officers who inspected my purchase and had no comment on the fact that I had 4 30 round magazines.

What gives here is that the laws passed by the Colorado legislature are enforced in some counties and jurisdictions and not in others. We’re here from government to help, as the saying goes.


Welcome my friend.


Hi Greg153. Welcome.

Yes, please get the 15 rounders. 3-4 of em, in case one ever malfunctions, help you with range practice. Neat that someone posted a link where to buy, and a discount. First check your city, county, in case they have even lower capacities. I gotta work with limits where I’m at.

I regret the fact it came with it in the box - does not mean you’re legal.

Then destroy the mag which is more than 15. You’ll feel a ton of weight lifted, I know I did brother.

Take care.


Hello and welcome @Greg153
If the shop that sold you the firearm knew it had two 17 round magazines with it, then they should exchange them for 15 round magazines. You shouldn’t have to pay out of pocket.


If the store will not swap out magazines, I would suggest doing an internet search for 15 round magazines for P320. At a quick glance I found OEM Sig Sauer for $45 with $4.99 shipping to aftermarket magazines as low as $12.43. Watch Sig’s shipping rates, I’ve never bought anything direct from Sig because they are always so high on shipping. There are many more to check out, but here are the links for the 2 magazines I looked up:
Sig Sauer P250, P320 Compact 9mm 15-Round Magazine (
ProMag Mag Sig P320 Sub-Compact 9mm Luger 15-Round Steel Blue (

Also, I do not know enough about the P320 platform to know if Compact and Sub-Compact magazines are interchangable between various configurations.


I suggest reaching out to Sig. If your purchase was NIB they may exchange them.


Welcome to the Community @Greg153.


More than likely the gun will not be sold with a magazine at all, as there would be no need. If it is it will only prove that the seller sees you as a sucker, or of low intelligence.


“There’s a sucker born every minute”


If I were you, I would just buy what’s legally allowed and keep the 17-rd mags.


Wow! I am impressed! That was a lot of good advice. Most significant to me, the recommendations were consistent. That tells me the folks on this board know what they are talking about vs. just shaing opinions (which I’ve seen elsewhere). Don’t get me wrong, I value opinons along with facts. There’s frequently a gem to be found when someone throws out a unique idea.

In a nutshell:

  • Get the 15 round magazines to be in compliace with local laws. 3-4 seems mags to be the common recommendation for a newbie (me).
  • Check with the vendor who sold me the gun to see if they will swap the 17’s for 15’s. If not, check with Sig, if that doesn’t work, keep the 17’s for emergencies and just buy what I need.
  • I saw good recommendations for aftermarket suppliers. For Sig directly, I was cautioned that Sig charges high shipping costs.

I think those are the most common points. I appreciate the good advice from everyone.

Thank you all.



Incidentally, in reality - even though a Co. has advertisement that the mags fits, off brands do not always fit or work we’ll. You take your chances, some will re-accept for refund, but have deadlines as to how soon you can send it back.

I found that if it’s made by the actual firearm manufacture, their own brand, they tend to fit and work better, but that’s from my minimal experience. “Old Timers” here may know better.

When I registered each of mine with the manufacturer, as part of the warranty as well; I then noticed some replied with coupon codes to save even more on their products. Might Sig offer that?


When I bought my xdm, the optics plate adapter things weren’t included. However, they give a code for a free one and cover shipping. When I wanted a second different plate, I contacted them and they just sent it to me foc. When they messed up the address, they sent another plate to me at the correct address, again, foc. SIG may be different, but if you explain the situation, I’m sure they will help you out.


As others posted, definitely get the 15 round mags and only use them.
However, keep the 17 rounders in case the law ever changes. Just pack them away somewhere for future use.