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AR upper, build vs buy, need some help im overwhelmed

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first off let me get this off my chest, holy h e double hockey sticks are there alot of ar parts out there.

 

ok, now that thats out of the way, 

 

I've shot a few ARs, never owned one, have a basic understanding of how they work, etc. I bought a stripped AR lower, half as a whim, and have no problem getting a part kit and finishing the lower. I should mention at this point that i traded my mini14 and all of my 5.56/2.23 (for some cool stuff) and am sitting on a small hill of x39 commie stuff. so i am going to build a bastard. (please dont hate me.)The merits of alternate caliber ARs can be debated in another thread, i did my homework, i know theres shortcomings, etc. its to be a range toy that uses a caliber i already have, we have mag limits anyway, so the whole 30 never runs from anyones hybrid mags thing doesn't bother me at all, and i  like different things. I also have a soft spot for dissipator builds. I also know that id have to do a mock dissapator due to the x39 favoring the carbine gas system from my research. Model 1 has an upper that fits the description https://www.model1sales.com/index.cfm?fuseaction=category.display&category_id=294 and id consider that to be a viable option with the adition of a rifle length MOE handguard. Heres where my confusion sets in, i hear that the barrel is headspaced and no problem to install into a striped upper. I also hear that i should be using an action block and some other stuff to assemble it, wich i have no problem buying to do the job. What im looking for is some help from those who know AR parts better then i do to help spec an upper, because my head is spinning from all the options, and lead me down the path with enough info so i can do a cost analysis on weather i should buy a completed upper or build the whole thing myself.

I apologize for the slightly more rambling then normal post from me, but my brains cooked from thinking about this

 

this is an idea of what im going for for anyone whos confused

post-6543-0-16598200-1450152476_thumb.jpg

but using asc mags with magbloks in them, and probably a houge grip as i love the one on my bastard ak

 

I feel i need to say this before gettign into price. those who have seen pics of my ak *cough post-6543-0-21608000-1450152959_thumb.jpgcough*) know im not inherently cheap, it probably cost me 3 times what some will say it should have to build what i wanted, but it also took me a year and a half to buy parts when the budget allowed. this will probably be another process like that, as it has the wifes blessing. Im looking for more cost vs quality when comparing against the aforementioned upper, not necesarily just how cheap it could be done for. am i making any sense?

if i am thanks in advance

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x39 upper differs in 3 ways

 

1) Barrel - as you already knew pretty much all carbine gas systems as I have seen

2) Bolt- The x39 bolt sits inside the same carrier as a 5.56 bolt, so pretty much any mil spec upper will do unless your gettin' fancy. Most x39 bolt carrier groups will come with a firing pin designed to penetrate hard russian primers. You can purchase full BCG's for x39. Many will recommend headspacing as it only takes a sec and is recommended when buying the barrel and bolt from two different companies.

3)Mags - you already planned for that ( blocked asc mags)

 

I've found x39 parts at the following sites, you can always try ebay if your into that...

 

 Palmettos state armory, JoeBobOutfitters, Aim Surplus, AR Parts Depot, AR-Depot

 

Try ARPartsFinder.com as well

 

ALL that being said...

 

If you plan on building other AR's than it is worth buying the tools such as an ar armorer's wrench. Once you select something other than the a2 flash hider on the model 1 upper, you will be at around 450 or 470. I bet if you cost it out it will be very similar to building it yourelf, throw it in a spreadsheet and see what it looks like. For me a build is the most satisfying.

 

Good Luck!

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Well let's start small. There's a million upper receivers out there, what makes a good one good and a less one less good.

 

I didn't exactly shop around for the lower, it having cool engravings are what started this. Ordered the lower then figured out what to do with it. I'm a little behind the mental research curve due to jumping in that way

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here's one thing to consider with a dissipator.    the barrel in front of the gas block is thinner by a tiny bit than where the gas block is.  a lot of dissipators will either have a suboptimal fit for the front gas block or a clamp on gas block.  i think the best way to do it would be to have the front of the barrel turned down to fit a .625" A2 front sight post with a small lip behind it to stop it from going further back

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Well let's start small. There's a million upper receivers out there, what makes a good one good and a less one less good.

 

I didn't exactly shop around for the lower, it having cool engravings are what started this. Ordered the lower then figured out what to do with it. I'm a little behind the mental research curve due to jumping in that way

 

 

essentially 

 

1. is it a forging using the proper metal

2. were all the holes milled to correct size

3. was it finished properly.

 

stick with a known brand that sells quality parts and go from there.  BCM are generally considered some of the best mil-spec stripped uppers.  

 

for $80 an aero precision one is probably perfect for just about any use.  

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I got my Spikes upper (with the door and forward assist) for something like $65 from Primary Arms because it was "blemished". Palmetto State Armory also sells blemished receivers if you aren't worried about cosmetics. I never found any issue with my blemish other than I think it's missing the Spikes logo near the charging handle, and you still have their full warranty regardless (EDIT: perhaps Palmetto does NOT have a warranty [see below] but Spikes does).

 

As far as the carrier I have an spare nitrided carrier (only the carrier, the bolt and small parts went into a piston gun) if you want it shoot me a PM.

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PSA blems are a gamble.  Last year I bought one that looked great, not a blem to be found.  However, it was out of spec.  The diameter of the opening where you mount the barrel was a few hundredths of an inch too wide.  Non-returnable so I was boned.  They may all come from three forges and look more or less the same, but there is a world of difference in the machining.

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I got a complete 7.62x39 upper with BCG from PSA. Fired one brand of Russian ammo fine but the primer strikes were really light! I could not get a single Golden Tiger

round to fire though the primer strikes looked okay!

I called PSA and a woman answered the phone and she knew her stuff! She asked if I had the hammer spring in backwards, I said NO!

She then asked if I was shooting steel ammo, I said yes, She said the AR was intended for brass ammo as the the primers are too hard on the steel stuff!

 

She said I could send the upper back and they would test it with brass cased ammo and if it worked, they would just send it back! I checked around and found lots of

people with this problem so I ordered a 7.62x39 "enhanced" firing pin and a Wolff extra power hammer spring from Black Rifle Arms in Florida. The firing pin change alone should do the trick

from what I have read but I ordered the Wolff spring just in case!

 

Just something to consider if you will be shooting the cheap ammo!

AR 7.62x39 Enhanced Firing Pin - 9.90

Wolff Extra Power Hammer Spring - $4.99

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the hammer spring and firing pin part i knew about, and need to do as it will be fed commie rounds.

 

the more I look into this the more it seems like the barrel is where i need to figure out cost on. theres a few hundred dollar range in barrels ot seems

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Take the firing pin and a file and trim a little off the shoulder of the pin on the front side, or take the bolt and trim a little, up to .005 off the back end. Works every time.

I read about the same things you suggest and people do say they will fix the issue but some have said that having the pin extended even a little bit

could cause pierced primers on non commie ammo. They say the enhanced firing pin is the exact same length as a normal pin but other dimensions have been changed.

Probably the shoulder trim you suggested!! For 10 bucks I will let them do the work.

 

If the new pin fixes it, I will leave it at that! I really don't want to have to use the heavier hammer spring as it will most certainly add a few more pounds to the trigger pull!

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