I’ve got a Govnah gas block that won’t cycle 223 with my new A5 setup so I would like to drill the ports out enough to cycle suppressed and unsuppressed. I haven’t been able to find any drill bit sets that go small enough to measure and/or dril the holes on the plates bigger

Individual pin gauges can be ordered.

Buy drill bits from drillhog on ebay. Drillhog #53 bit
And find a machinist drill bit size chart. https://www.engineersedge.com/drill_sizes.htm
That should get you what you need.
I usually use a caliper to measure mine and they work fine.

What bbl and gas system lengths?  What is the current gas port diameter?

Don’t worry, not drilling an actual gas port, but a plate on an older gas block. Look up the Govnah Gas block



Barrel is 14.5” midlength gas system with an A5H2 buffer system setup. Standard rifle spring but going to update that soon too.

Why don't you do something easier and less expensive and more reliable.
Go back to the mil-spec receiver extension, action spring setup and adjust mil-spec buffer as needed?

Barrels are hard - do not use chinese pile of shit drill bits or you're going to have a bad time.  Order the individual drill bits you need/want from McMaster, 100% chance they'll be american made.

Find a pin gauge set on ebay.  The only chinese pin gauge set I'd recommend is from a company named "shars".  They make surprisingly high quality metrology equipment.

https://www.shars.com/products/measuring/pin-plug-gages

If you drill it oil the drill and the gas port and go slow.  Low rpm.  Don't pressure the bit into/through the port/hole, let the weight of the drill slowly eat it's way through.  Stop and oil again.

I've only done two or three.  No problems so far.

My experience with drilling dimples for gas blocks is that the nitride surface is very hard. Once you get through the drilling seems to get much easier. You'll definitely want a cobalt bit, and I've heard carbide is even better but they are a lot more expensive. I ordered a couple cobalt ones rather than one carbide and was happy with that decision. If it's phosphate/CL it will probably be much easier. My understanding is that the hardness of cobalt is only slightly above that of nitride, which is why it's difficult to drill. I definitely benefitted from the use of a drill press.

I second the suggestion of buying from mcmaster. They have reasonable prices for individual bits.

OP is not drilling the barrel.

I do a lot of wildcats so I have drilled out dozens of gas ports.  It’s not Voodoo or rocket surgery.

 I have my barrel maker do the initial gas port at a much smaller than needed size and adjust the port size until it works with a powder that should work.  I’ve never needed an AGB yet.  I don’t get fancy with the drill bits but I do use good ones.  I like jobber length high speed numbered bits from Brownells, tap magic cutting oil, and a solid brass rod in the barrel to prevent drilling the off side.  Enlarge .001-.004” at a time and retest for function.  You remove so little metal each pass that you don’t really feel it cutting so don’t push.  Advance slow, use good cutting oil, and even good quality but cheap HS bits last forever.  And don’t use your gas port bits for other things.  If you do, replace it with a new one for future gas port drilling.  Sharp bits, good oil, and slow advance speed never leaves a burr inside.

This isn’t a fighting or go to war rifle. I’ve got a Colt with an ACOG if I need a rifle. This is just more for an all around build that can do a little bit of everything. I’d also like to see just how smooth shooting I can get it.

How does the extended receiver extension help?

I mean it’s not any easier or harder than a regular extension, and I have never read a claim saying that it’s less reliable when tuned correctly. The gun doesn’t cycle on a lower with a regular carbine buffer because I tried it with a different pistol lower so the plate has to be opened up either way. But I can honestly say that there is a difference, the recoil impulse is different as I tried 2 different uppers on 2 different lowers and preferred the A5. It’s only on one gun that’s not a fighting rifle, so it shouldn’t be a problem.

I bought a set of small bits from Amazon that cover the range of typical gas ports pretty well —  wire numbers 60 to 41.  I got it for $15, though it’s $25 now.  You can search for the stock ID:  B075RCB4Q6

I use their shanks as crude pin gages to figure out what size port I’m dealing with.  Drill shanks tend to run a smidge smaller than the nominal drill size, so measure.

That said, the preferred tool for opening up an existing hole is a reamer. They come in the same sizes as drills.  I’ve gotten a several off eBay for quite a bit less than you’d pay from a mainstream industrial supplier like MSC or McMaster-Carr.

best left to a smith

A set of drill bits