I have spent dozens of hours reading current and archived posts, and find myself in the same quandary.  It's time for me to finally build a dedicated Colt mag AR.  I want to know your opinion on the best block, and who to pin it, along with what you think the best bolt and hammer.  Cost is no consideration here.  I would just buy a Colt and chop the barrel, but I'm thinking of a DOE replica, so my current focus is on the lower.

In advance, I thank you.

ok, not an expert by any means, but I have two Glock mag dedicated lowers for USPSA PCC that I've been competing with, and sorting out for a couple of years, and a bottom load Macon Armory mag adapter for my registered SBR lower... it is held up in place with a button head cap screw and fore and aft tension by two set screws in the front of the mag well....

I know you are you looking for a Colt clone... but other than cosmetics, I don't think you really need to pin the block... the side walls of the adapter are pretty thin, but the Metalform Colt style magazines are held well... unless you plan on slamming in reloads that is

I have both an AR claw and pistol style extractors that each work well... the claw is on an NFA two piece bolt, and I've used one PSA bolt pretty much exclusively for over 8000 rounds without a problem...

I've found it advantageous to round the strike end of the firing pin so the hammer strikes it close to the centerline

I've used OEM fire control group hammers as well as RRA NM hammer which has most of the mileage

Are any of these the ones you already read ??

https://www.ar15.com/forums/AR-15/Colt-633-DOE-clone-project/123-732492/

https://www.ar15.com/forums/ar-15/Colt_633_DOE_parts/123-702892/

https://www.ar15.com/forums/ar-15/Colt_633_DOE_barrel_question/123-699583/?page=1

https://www.ar15.com/forums/ar-15/Colt_633_DOE_questions/123-706920/

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Yep, sure did.  Your post reinforces not to do it, and get a CZ.  Don't want recreational play gun.  Thanks.

I use the Hahn mag blocks on my four AR 9mm.  Easy to install and you only tighten one set screw after inserting the bock into the mag well.  Built a couple of others for other competitors here.  I bought the bottom ones(you insert up through the bottom) but I've heard that the top loaders ones are good also.  Never a problem with any of them and I've shot thousands of rounds thru them in competition and practice.  Using a taccom bolt now, with the AR-15 claw extractor, but have also used the standard bolts also.  Your choice.

Colt is currently using a one piece mag block with only two pins holding it in place. I removed my 1 piece Colt block to refinish the lower and I found it to be the exact same block that Rock River Arms sells/uses.

And John Thomas will drill and pin new undrilled  RRA/Colt 1 piece blocks because they are aluminum. He doesn't like to do the 2 piece steel blocks for several reasons.

I had JT drill my third pin hole in my 2 pin 1 piece block lower so it looked like the older 2 piece block 3 pin lower on the out side on my DOE.

I used a Colt 9MM bolt and I had JT ramp it so I could use a standard hammer. But I would think the CMMG bolt would be a good bolt also.

I have several brand of bolts and they all work great I think.

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A dedicated Colt mag gun would imply buying a lower that only fits Colt mags, not a standard lower and mag block.

Thank you, sir!  Exactly the answer I was seeking:  well done.

I vote Hahn block with Metalform mags.

When I put my first 9mm AR together years ago this was the best recommended setup.

I run the top loader with a Colt long finger bolt catch. Runs everything without fail including hollow points and truncated bullets.

Never had a single failure.

+1 on the Hahn top loading block. Mine runs like a sewing machine. I have several bolts Colt and tool craft.  They run fine.  Plenty of used Colt Carbines out there that will require little modification to get to where you want to go.

If you want a 9mm built to a specific spec call Rudy at Macon Armory.

9mm carbines can be habit forming. Keep an eye out for Black Friday sales at PSA. If they mark mags down....buy a herd of them.