SIG P320 & P365 FCU - Build Your Own

[Thy.Will.Be.Done]

So this has me tempted into just building my own to preference rather than going with an off the shelf option... but the cost is quite steep just for the FCU. Seems WAY overpriced for what it is at $350 just for the FCU, I could see it costing them not even 10% of what they charge to produce this. That said, I like it and want to build so of a Frankengun to preference with it but that would put the cost of the build at around $1k w/ TiN barrel and tan everything.

84968

https://www.sigsauer.com/fcu

Titanium Nitride looks cool but does it help the trigger pull smoothness or anything tangible other than add bling? Also had a thought to just buy an NRA P365 or P365XL for the coyote frame and slide than switch the FCU and sell the black standard one. Did I mention I don't like black parts on tan guns, lol. What are the standard FCU's selling for second hand these days?

[Guerrero]

Seems WAY overpriced for what it is at $350 just for the FCU, I could see it costing them not even 10% of what they charge to produce this.

Well, technically the FCU *is* the firearm.

[KevH]

So this has me tempted into just building my own to preference rather than going with an off the shelf option... but the cost is quite steep just for the FCU. Seems WAY overpriced for what it is at $350 just for the FCU, I could see it costing them not even 10% of what they charge to produce this. That said, I like it and want to build so of a Frankengun to preference with it but that would put the cost of the build at around $1k w/ TiN barrel and tan everything.

84968

https://www.sigsauer.com/fcu

Titanium Nitride looks cool but does it help the trigger pull smoothness or anything tangible other than add bling? Also had a thought to just buy an NRA P365 or P365XL for the coyote frame and slide than switch the FCU and sell the black standard one. Did I mention I don't like black parts on tan guns, lol. What are the standard FCU's selling for second hand these days?

It's significantly cheaper to just buy a pre-built P320 than it is to "build your own," especially if you are eligible for the "Pro" LE guns.

[Thy.Will.Be.Done]

It's significantly cheaper to just buy a pre-built P320 than it is to "build your own," especially if you are eligible for the "Pro" LE guns.

Yeah, like half as much it's brutal. Cashing in on parts is big business for SIG apparently.

[HeavyDuty]

It's significantly cheaper to just buy a pre-built P320 than it is to "build your own," especially if you are eligible for the "Pro" LE guns.

Even if you’re not and have a compliant dealer.

[Bergeron]

While I certainly get the downer of the price, this is the model of firearm sales that I most prefer. I'm gonna want something unique and peculiar to me, and I'd rather buy the parts I want, and avoid the parts that don't. It's still a price advantage over buying a whole gun, plus all the replacement stuff I want to play with, and letting the surplus pile up on a bench or in a box.

[KevH]

While I certainly get the downer of the price, this is the model of firearm sales that I most prefer. I'm gonna want something unique and peculiar to me, and I'd rather buy the parts I want, and avoid the parts that don't. It's still a price advantage over buying a whole gun, plus all the replacement stuff I want to play with, and letting the surplus pile up on a bench or in a box.

Buying just the Custom Works FCU and magazines alone typically costs more than buying a complete gun that comes with mags.

Buy a gun, keep the FCU and what you want and sell what you don't. You're still way ahead of buying just the FCU and everything individually (coming from a guy that owns a Custom Works FCU).

[tlong17]

Buying just the Custom Works FCU and magazines alone typically costs more than buying a complete gun that comes with mags.

Buy a gun, keep the FCU and what you want and sell what you don't. You're still way ahead of buying just the FCU and everything individually (coming from a guy that owns a Custom Works FCU).

That's what I did. Built the same gun I wanted through the custom builder but saved $300 by just buying a base 320 compact and going from there. These can be found for $450-$475.

[Mike C]

I think the idea behind building your own is excellent. But I hate all the stupid color schemes with the predominant issue being certain things aren't available. For example, I want a manual safety FCU for a 320. The only way for me to get such is to buy a stupid commercial version of the M18/M17 then buy the slide, grip module that I want, etc. It's frustrating. I would be fine with paying a little more for the ability to get a gun built exactly the way I want without having to piece mail, buy sell a bunch of different crap so I don't get wound up over having a bunch of half built guns laying around but Sig being Sig execution is generally shit. I say that having been super pissed at them in the past yet still owning 7 different guns from their current offering 5 being P365's/XL's and now a damn Spectre whatever comp model. Which by the way is freaking excellent.

[HeavyDuty]

I think the idea behind building your own is excellent. But I hate all the stupid color schemes with the predominant issue being certain things aren't available. For example, I want a manual safety FCU for a 320. The only way for me to get such is to buy a stupid commercial version of the M18/M17 then buy the slide, grip module that I want, etc. It's frustrating. I would be fine with paying a little more for the ability to get a gun built exactly the way I want without having to piece mail, buy sell a bunch of different crap so I don't get wound up over having a bunch of half built guns laying around but Sig being Sig execution is generally shit. I say that having been super pissed at them in the past yet still owning 7 different guns from their current offering 5 being P365's/XL's and now a damn Spectre whatever comp model. Which by the way is freaking excellent.

There are currently two other ways to get a P320 FCU with MS:

1. Find a MA spec Compact, SKU 320C-9-BSS-MS-MA. This will get you one without an optic plate, or you can sell everything but the FCU and build your own. I found this would be quite a bit cheaper than a M17 or M18, but the M17/M18 parts might sell for more. Dunno.
2. Send your FCU to AB Prototype and have it milled and converted. This will kill your warranty. I have one out of a LE SKU AXG grip pistol there for this right now.

I also was able to find one of the elusive M18 Bravos. Homey don’t do goat poop brown pistols.

[Thy.Will.Be.Done]

Well, technically the FCU *is* the firearm.

That's a joke, isn't it.... :)

[Guerrero]

That's a joke, isn't it.... :)

Not to the ATF it's not.

[Thy.Will.Be.Done]

Not to the ATF it's not.

You're right. I just have to laugh at that definition, that would be like saying the chassis of your car IS the car lol.

[HeavyDuty]

You're right. I just have to laugh at that definition, that would be like saying the chassis of your car IS the car lol.

Well…

[Mike C]

There are currently two other ways to get a P320 FCU with MS:

1. Find a MA spec Compact, SKU 320C-9-BSS-MS-MA. This will get you one without an optic plate, or you can sell everything but the FCU and build your own. I found this would be quite a bit cheaper than a M17 or M18, but the M17/M18 parts might sell for more. Dunno.
2. Send your FCU to AB Prototype and have it milled and converted. This will kill your warranty. I have one out of a LE SKU AXG grip pistol there for this right now.

I also was able to find one of the elusive M18 Bravos. Homey don’t do goat poop brown pistols.

I wasn't tracking the MA spec model. Thanks but it's neutered, which super lame... On another not aren't the internals of the commercial M17/18 and the MA different than the DHS/Pro model for LE? I thought I read a post by HCM or someone in the know that they were and were not on the approved list for IOP. But seriously either way you slice it you still have to buy one of the two models, gut it and get the slide you want, (pro for me) I love the RMR mounting footprint. As for sending a gun in to be fiddled with I looked at it but at this point it is just out of my comfort zone. I just want an out of the box solution, I'm okay with paying a premium because I don't want what they are offering but am beside myself that they offer everything but what I want. Story of my life.

Sig is essentially king of modularity, I love being able to gut, strip or canabize any of the P365 series to use with anything else in the family. It is incredible. Not to mention ridiculously reliable. Repetitive I know but I just wish that Sig would stop with all the weird custom baby poo color schemes/stupidity and just focus on being innovative like they have with solid execution. This is not to say I am shitting on them as I feel like I probably sound like I am because they have absolutely changed my mind between the P365's, Cross and Rattler. All have preformed exceptionally. They are really the epitome of what modern engineering and production are capable of.

[Dave Williams]

I’ve also been specing out custom sig 320s on the website. It reminds me of when I was a kid and I’d spec out an entire bmx bike piece by piece. I’ve been renting various sig320s every week seeing if that scratches my itch.

[Hambo]

You're right. I just have to laugh at that definition, that would be like saying the chassis of your car IS the car lol.

So you've never built a car or motorcycle.

[Thy.Will.Be.Done]

So you've never built a car or motorcycle.

No but I'd argue it's only a car or pistol when it has ever piece needed to make it function, assembled correctly. That's why we call a car a car and chassis a chassis, the chassis is a part of the whole... not the whole.

[JCN]

No but I'd argue it's only a car or pistol when it has ever piece needed to make it function, assembled correctly. That's why we call a car a car and chassis a chassis, the chassis is a part of the whole... not the whole.

I’ve had plenty of race cars that I’ve blown engines that were still cars. You can swap engines like uppers, they’re not the defining characteristic of the car like a chassis is…

[Thy.Will.Be.Done]

I’ve had plenty of race cars that I’ve blown engines that were still cars. You can swap engines like uppers, they’re not the defining characteristic of the car like a chassis is…

My point is one of those 'cars' is about as useful as a hammer in getting you from A to B, therefore I wouldn't call it something it's not. If you took the head off of a hammer could you still call it a hammer? If I break a knife, I'm probably going to call it a 'broken knife' and not just a knife. I think I've made my point but I'm sure there's more that will be made of this, I didn't mean to derail the thread so let's get back on topic.

[JCN]

My point is one of those 'cars' is about as useful as a hammer in getting you from A to B, therefore I wouldn't call it something it's not. If you took the head off of a hammer could you still call it a hammer? If I break a knife, I'm probably going to call it a 'broken knife' and not just a knife. I think I've made my point but I'm sure there's more that will be made of this, I didn't mean to derail the thread so let's get back on topic.

Is a car without gasoline still a car?

What about a car that you forgot your keys at home? Does it cease to be a car because you can’t drive it?

[octagon]

To add to the build your own Sig FCU. When I was at SHOT there were two companies that said they were working on having 80% 365 FCUs. Seeing how they are not stamped like the already available 320 FCU 80% kits it will probably take more effort or cost more but the option is always nice to have if it works reliably. Polymer 80 also said they were working on Sig 365 stuff so that may be FCU or grip modules he wouldn't clarify.

[Mike C]

To add to the build your own Sig FCU. When I was at SHOT there were two companies that said they were working on having 80% 365 FCUs. Seeing how they are not stamped like the already available 320 FCU 80% kits it will probably take more effort or cost more but the option is always nice to have if it works reliably. Polymer 80 also said they were working on Sig 365 stuff so that may be FCU or grip modules he wouldn't clarify.

This will be interesting considering the current political climate and ATF/DOJ's present attitude.

[Hambo]

No but I'd argue it's only a car or pistol when it has ever piece needed to make it function, assembled correctly. That's why we call a car a car and chassis a chassis, the chassis is a part of the whole... not the whole.

I understand you, but according to ATF a fully assembled G17, an AR lower, and a SIG FCU are all firearms. The DMV may consider your whole car, truck cab with VIN tag, chassis, or bike frame to be the vehicle. They make the rules, we just play by them.

[Texaspoff]

No but I'd argue it's only a car or pistol when it has ever piece needed to make it function, assembled correctly. That's why we call a car a car and chassis a chassis, the chassis is a part of the whole... not the whole.

Well you can have it out with the ATF, because I can tell you as an FFL holder, you won't win that argument, and they will give you a nice place to stay for a while, if you don't agree and do it your way anyway.




TXPO

[358156hp]

Sorry to be a buzzkill. But I just bought one on GunBroker for about $260.00, new, from a dealer. Had to pay shipping and sales tax of course. Titanium Nitride is used to harden the parts surface, and apply a measure of lubricity. If you go the "buy it now" route, you will pay $350.00, sometimes with, or without shipping. FWIW. these FCUs were recently being scalped by dealers at auction at around $600.00 or so. They'd start the bidding at around $300.00 or so, and the bids would run up to $600.00, often with a $600.00 "buy it now". I've wanted one ever since they were announced, but not $600.00 bad. Like others have mentioned, used P320s are only around $400.00 or so in my area, BUT they don't have the same FCU that this Custom Works is. There are important differences.

Anyway, I got the one I need, and it cost far less than $350.00.

[Jimichanga]

To add to the build your own Sig FCU. When I was at SHOT there were two companies that said they were working on having 80% 365 FCUs. Seeing how they are not stamped like the already available 320 FCU 80% kits it will probably take more effort or cost more but the option is always nice to have if it works reliably. Polymer 80 also said they were working on Sig 365 stuff so that may be FCU or grip modules he wouldn't clarify.

I would be nice if some company would design the 320 clone with a replaceable ejector. That is definitely the weakest link of Sig's FCU design.