Colt Sporter Upper Needs a Barrel Assembly- Need Help

Yesterday was the 16th anniversary of my deployment to Kuwait (in preparation for the invasion of Iraq). Gripped by nostalgia I purchased a Colt Sporter HBAR Match upper last night in order to create an M16A2 clone to honor the musket that served me so well in the fight. The upper will be mated to a 6920 that I’ll put an A2 stock assembly on. My concern is which barrel to use. After several hours of researching the archives here, my understanding is that it’ll be fine (from the standpoint of reliable rifle operation) for me to use a Standard BCM 20” barrel with M4 feed ramps and a F marked FSB. Please let me know if I have erred in my conclusions.

Many Thanks!
A

That’s one of the better barrels that you can buy in that configuration.

To drill down a bit: are you saying that the barrel’s M4 feed ramps, mated to the Sporter upper, shouldn’t impede the proper operation of the rifle?

Your Colt upper from the 20" Match HBAR will not have M4 feedramps in it. The BCM barrel you have selected is not compatible with it. Are you trying to install the BCM barrel in the Colt upper receiver?

If you want to create an M16A2 clone, then you need to buy a preban R6551 Sport Target Model (this is not an HBAR rifle) and install a Colt M16A2 barrel in it.

Hell. That’s some sad face news, though much appreciated.

So I bought this upper off of Gun Broker. After reading your post, I contacted the seller and he told me that he has a Colt A2 style upper with M4 feed ramps that he’ll provide me in lieu of the Sporter upper. I reckon, however, this can’t be true given what you’ve just told me.

You are getting yourself into a massive rabbit hole.

Yes there are carbine A2 uppers with M4 feedramps.

You also have to pay attention to the front pivot hole of your lower. What size it it?

IMHO, you need to abandon the parts you already have and buy this:

https://www.gunbroker.com/item/795443098

Find a new old stock M16A2 barrel for it.

Also, perhaps I’m being imprecise using the word “clone.” I want a rifle comprised of a Colt upper and lower that has the major styling cues of the M16A2. I just want an Colt AR with a 20” barrel and a damn carrying handle :blink::blink::blink::rolleyes:

Apologies. I was writing my last note and didn’t see your last post. Thank you for the link. The pivot hole is .250.

So I have this $200 upper coming now. I don’t want a Colt paper weight. So, if this upper he sends me has M4 feed ramps and fits my lower, is the BCM barrel idea workable, if not perfect?

There is a 20" FN A2 barrel for sale in the equipment exchange. I am certain if you IM the seller, he could answer any compatibility questions.

I would provide a link, but I don’t know if that is Kosher…

Andy

This A2 upper from Fulton gives you the option of M4 or non-M4 feed ramps https://www.fulton-armory.com/upperreceivera2usgi-1.aspx

Check with https://retrorifles.com/collections/barrels/products/20-m16a2-rifle-barrel-assembly-with-a2-muzzle-device and see if their 20" A2 barrel comes with M4 feed ramps or not

Are Retro Rifles legit? I only ask because I’ve never heard of them in this forum.

I’ve yet to use them. Some guys on TOS have their noses bent out of shape over RetroRifles because shipping takes a few days longer than they like. RetroRifles has a 10" upper I’m interested in for a GAU-5/A build I’m planning. One reason we don’t hear about RetroRifles here is that they specialize in retro ARs.

Also check with https://www.tntesales.com/ for 20 inch A2 barrels

I’ll speak with them. They may be able to do something with the upper I purchased. I read their •About Us• and my instinct tells me they are earnest.

I’d love to see your GAU-5/A when you complete it. I think it and the XM177E2 are the sexiest ARs ever conceived. I was lazy and purchased Troy’s GAU-5/A and XM177E2. My dad carried the former and my grandpa the latter in Vietnam. It was worth buying both of those rifles just to see the joy both my dad and grandpa experienced when we took the rifles out to the range. It was also fun to hear them bitch about how much heavier the AR I had set-up like the M4 I used in Afghanistan was.

There are plenty of people that claim it’s perfectly ok to run a rifle upper with an M4 feedramp barrel. I’ve never done it, but I’ve seen a bunch that work just fine.

AK Doug,

Oh okay, I thought I gone batsh*t coo coo for Coco Puffs after all of my research last night. I know it’s can’t be optimal but I’d have to go through a few ARs and an ARX before I’d need this one to defend the family et al. Many Thanks!

So I’ve confirmed with the seller that he will be swaping out the HBAR upper for a lightweight Sporter upper with M4 feed ramps. Cloning asthetics aside, this lightweight Sporter with M4 feed ramps should have no issues being mated with a modern 20” barrel also with M4 feed ramps, correct?

M4 to M4 = GTG

Excellent. Thank you. Ha Ha Ha! I feel like a derp when you put it that way. It’s just that old Colts make my head spin with their myriad variations.

The Devil is in the details. Learning the details and paying attention to them will make your life easier.

We all gotta start someplace.