Ugh the saga continues, so I was able to acquire enough funding to buy a "delta ring parts kit" for this upper receiver I'm putting together cause I was missing the spring part  >< you know what doesn't need one of those? My fucking SKS xD

But so I used the spring out of the kit from CMMG and it made the original delta ring itself, the spring, and the metal ring that the gas tube goes through, whatever its name is it isn't in my AR15 builder book specifically, neither did the book tell me where this part specifically went, either up against the delta ring itself or the receiver, it just mentions the "slip ring spring" and aligning it with a screwdriver which I tried to give this a try and got that far before realizing the vice block that holds the upper receiver isn't a joke it's actually needed, so I just ordered one and the barrel nut wrench to finish this build.

Any explaining of what that metal ring that the gas tube goes through is? I will note that this AR15 is a true old A2 and maybe it's a little different than modern day, the lower receiver shell was the only part missing in the box, the guts and everything was in the box but I got a nice lower from palmetto state to avoid any possible issue with building it from literal step one, so I have a possible issue perhaps somebody can also explain, the buffer tube weight thingy

So apparently they come in different weights, you know what gun doesn't need that? Yeah apples and oranges I know, anyway my A2 upper is going on a completely new magpul furniture lower, the collapsible three (or six?) Position stock, so the classic huge A2 stock that this AR originally used I plan on switching over to it with a kit I can't find in stock to switch it from the magpul to the A2 apparently they are a different size tube or something, but my question is this, do these weights matter with these builds? Since they aren't compatable will this cause reliability issues?


FINALLY THE QUESTION I POINTED TO IN THE TITLE, Brownells sells a orange front sight pin alignment thingy, seems you lay your A2 with it in the right spot on the barrel and lay it upon this block and it holds it for you to tap the pins in, but it's expensive :( and it took me about a year to build up the money for a delta ring parts kit and the two other things needed to complete this, I have the patience of a saint in my 20s I'm weird... And self aware

So is that thingy really necessary or can I just lay the recieve in its side and place enough playing cards around to punch the pins in right? Ill have another set of hands on hand if needed during this part as well, AR15 DIETIES I call upon your help for this pathetic A2 swamp build, and I do live in a swamp with like zero service until Elon musk's device arrives so if I don't respond for a few days it's because I havent went to town for internet service, seriously welcome to Florida XD

"Mil spec" uppers, m16-modern ar15s, are all the same.  The ring clips onto the notch on the back of the bagel nut.  It holds the delta ring and spring onto the barrel nut.   Do this before installing the barrel in the upper.

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ETA.  You will need a vice block and clam shell or reaction rod.

There are 2 types of receiver extensions, commonly called buffer tubes.  One is for rifle stocks, not collapsible and one is for carbine stocks which change position.  They each use different springs and buffers.  So you cannot use one for the other.  The weight depends on your barrel length and gas tube length.  If you have a 14.5-16 inch m4 profile barrel, a standard carbine buffer and spring should work fine.  You dont need an H2 or H3 buffer.

I dont know if you can use a standard carbine buffer/spring with a 20 inch barrel?  Also, I have heard if you remove the front sight, it will not always go back on as straight.

Canuck Military standard issue

If you remove a pinned front sight base (which is not easy), you can easily pin it back in exactly the same place, but why would you want to remove it?

It should go back on straight.

Talk about the long way around things.....

OP, your delta pack should have 3 pieces: snap ring / spring/ actual slip ring for retaining the handguards.
You will need a set of snap ring pliers to install the snap ring into the groove on the barrel nut. Plenty of how to vids on YouTube, etc.


If your front sight base is taper pinned (standard application) it will return to the exact alignment once reinstalled. And no, you do not need a front sight block. A section of hardwood and a pin punch/hammer will get it done.

A bench vise , receiver action block, and proper barrel nut wrench are imperative.

Apply grease to the barrel nut threads, torque the barrel nut to the correct value, 30-80 ft lbs.
The torque sequence should be performed 3X. Torque/loosen, repeat.  

If using a true A2 rifle stock and "buffer tube", you want a rifle buffer assy.

I don't know if this will help or not but might help.

This might help you

Because it was found completely disassembled X_x lol, I found a box in the corner of the family garage and opened it and to my shock was 98% of an upper receiver, completely disassembled so I didn't do that part. It was missing a few weird things, super cheap parts, and I had zero tools to build it, and only a rudimentary understanding of how to do it.

So after about ten years it's coming together! I think I'll have her running once the parts get here, I bought a torque wrench and have access to a pretty stocked shop so got a vice all ready. I'll definitely post a crap ton of photos once the super duper long term project is done.

The box contents were odd, contained enough parts for almost two lowers minus the shell, about four complete disassembled triggers, some assortments that I asked for help identifying here. It's from my dad's time having an FFL, he gave a few clues of the origins, the lower parts are DPMS and Colt, the upper receiver parts are Colt, and it's an Hbar 20ish inch barrel I took a pic here for everyone. When I measured the thickness it was smack between an Hbar and bull barrel thickness in the numbers I measured, and I measured with a micrometer not a measuring tape XD I know what I'm doing, if I don't then I ask so I don't F anything up (though I might have included the throat in the measurement of the barrel which isnt counted I don't think, but also doesn't have the A2 flash hider which I think is counted?)

But you're saying if someone took the pins out, which obviously they did, then they can be put back in just smack them in place once I determine which goes where? With care and precision ofc, and I don't need a special mould to cradle the whole thing in?

Thanks a bunch! It's like the guide I purchased, but it lacks the detail I need, for the step I'm doing which is step 8 as follows

"8. At this point, we need to remove the delta ring, spring, and snap-ring that holds it all together. Grab your snap ring pliers, and slide off the snap ring, spring, and delta ring as shown:"

So do I require snap ring pliers? I'm never one to skimp on necessary equipment, it's taken years to save up my pennys and get what I need, but I see a lot of stuff that seems to be to "help" you do the job easier, like a bunch of stuff for gas tube alignment like the Genie or whatever it's called, eventually I'll ask about those too, but back to the point. Snap ring pliers sound nifty but I still need help with the whole snap ring thing.

Because firstly I'm not sure what way the spring is supposed to be facing, exactly what do they reference when they say putting it on the spring? I have aphantasia somewhat similar to CWS disease, I can't picture something in the mind or easily learn through pictures unless it's extraordinarily specific so I can physically do it myself, normally I have no issue learning but small specific actions like snapping a snap ring onto a spring which isn't described except "snap it on with snap ring pliers", make zero sense to me, but for everybody with a functioning brain the walk through is perfect <3 I just need a tad bit more specificity

Thanks a ton for the info! This Sally is a true old build but because it's in a box of assorted other treasures, I'm unable to tell exactly what she looked like before being stripped naked, but from what I can gather it either had a carbine stock because it has the parts that go to one, including a fancy "clip" of sorts that allowed it to attach a sling to either side, it's possible I'm saying that wrong but anyway.

The other possibility that I think is more likely is she was truly a complete A2 build with big fat long A2 stock included good for my six foot frame! <3 but the one thing the box didn't contain was any lower shells, just the parts to lowers and a few 99% complete uppers minus barrel gas tube assembly and all, though all those parts were included... But they all were disassembled as I said. So I kinda skipped over buying a lower shell and putting all that together for the first time hoping it's all done right. So I purchased a very nice magpul furnished lower from PSA, and I only realized later that the A2 stock is incompatible with this magpul adjustable stock and needs a $80 conversion kit which is out of stock all the time and I never have that huge amount of money on hand to buy one.

But check out my picture of my barrel, so the magpul multiple position stock won't let my upper function properly?

Also side note, the 14.5in barrel you mentioned is an NFA item, do people really own that many of those short barreled AR's? Or do many people just assume barrels are that short often when they aren't?

Thank you so much!!! The pic helped somewhat, but I am still confused on the specifics of which way the spring faces and how you snap it on, as I explained once, that's not because your help is bad, I just have to have a bit clearer more specific directions if you can. And I require the special pliars? Or are they just a handy tool, I can have other pairs of hands to help if needed. Also what is a reaction rod, I've never heard that term and I don't think it's in my manual.

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