Guys, I’m getting bogged down in the details.  I’ve read the thread on modified gas ports and I’m no closer to a solution.  

I have a factory 14 barrel for the SCAR 16.  I’m going to get it pin weld with a Dead Air keymo FH for the non SBR 16 inches.  I will be using a Saker 556 on the rifle.  

Where should I start with exchanging the gas port?   What diameter should I start with?

Ideally I’d love to have it run well with suppressed, flip the switch for non-suppressed    

Thanks.

Since your barrel is factory, it comes with the proper gas jet for that barrel length.  I have a factory 10" barrel on mine, and haven't changed a thing. It works great both suppressed and unsuppressed. The discussion about changing jets comes from people who are cutting down 16" barrels and need to swap jets to get things to work reliably.  Unless you are really trying to go down a rabbit hole, you should be fine with what you've got.

The gun is over gassed from the factory.  On the SCAR 16 I don't think it's as big of a deal as on the 17.  I don't hear of issues with canted receiver bolts, broken bolt carriers, etc.  If you want less gas in your face when running suppressed I'd swap the jets.  The 16" barrel comes with a 1.35mm gas jet and the the 10" comes with a 2.0mm gas jet.  I'd assume the 14" is around 1.5mm.  If you still have your 16", maybe throw the gas jet from that in and see how it behaves.  Otherwise, I'd order a few different jets and see what works.

Can’t stress it enough. Every scar owner should properly tune their SCARs with the gas jet. From factory. All of them are overgassed. If your gun runs in suppressed setting unsuppressed. You are over gassed.

Canted receivers are either from:

Running the gun suppressed without tuning the SCAR to that suppressor...created a severe overgas situation.  

People running KDG or other aluminum aftermarket stock hinge as that gets rid of FNs secondary buffer...the polymer stock hinge.

If you put those two together...you are just asking for more trouble.

There are two things you need on a SCAR: gas jet tuning and mototech rubberized buffer pad....

When I had my 16" chopped to 11" - PMM set the jet size and provided a +/- size as well for tuning if needed.

Runs fine.

PMM did mine at 16” overall length and sent it back with his Recommended gas jet.
I have played around quite a bit and it runs fine with a PMM 1.35 gas screw.
Much less gas and recoil.
YMMV.

There is a lot of good info in the "Gas Jet" thread a few lines down on this page.  It seems a 1.35mm is what most people are using in the stock length 17s.  I'm using one in mine and it made a noticeable difference in recoil impulse without a suppressor.  I haven't run it suppressed yet with that size jet to confirm, but I'm thinking it's the one I'll stick with.

Great Scar gas jet video, in case you have not already seen it.

I recently took my Scar16 to the range that I had the barrel shortened to 16” overall length. The muzzle device is an AAC flash hider/silencer mount.

It was 100% reliable with the factory gas port except it would only lock back on the last round approximately 40% of the time with quality 55gr ammo.  With 77gr MK262 it would lock back 100% of the time.

I ordered 1.4 and 1.45 ports to try. I hope this helps and always appreciate feedback. Thanks.

The 1.4 gas port locked the bolt back on my ~14.5" SCAR16 barrel 100% of the time with Federal 55 grain .223 pressure ammo.  I assume my factory port was 1.35