Need some advice / first NEW build upper

[snipernuts]

hi guys!!  ok, so like I said, i'll be asking LOTS of questions!!  so here we go :)

Just bought a complete Alexandria pro fab 308 platform, AWESOME buid that this guy did, under 1MOA at 100yrds smoking accurate!!  So, NOW I went and bought a stripped PRO-FAB upper and started to buy some parts, here come the questions:

1.  I have a FN mfg 16" barrel, stripped, 1/10 twist - I also bought a yankee hill front flip up sight / gas block - Question - what is the best way to attach these?

2.  handguard selection - what models are compatible with the PRO-FAB (I'm pretty certain that these are DPMS compatible) just not 100% certain

3.  bolt selection - again, what is a good compatible BCG for this

 

 

any help would be greatly appreciated!!

 

thanks guys!!

kup

[survivalshop]

Some questions ,

 Is it a DPMS or AR 10 type Barrel ?

If so , what is the Gas Block diameter of the Barrel & did you get the same Diameter Gas Block ?   (   .750", .836" or .936 "  )

Gas Blocks on 308AR's are just like AR 15 's, they attach in several  ways , Set Screws , Clamp type & Pined type ( like the Tapered A2 sight tower ) What is your Gas Block attachment type ?

 BCG depends on Barrel type , some say it doesn't matter , but I like to keep to type , to pick the BCG to use , be it DPMS or Armalite .

[snipernuts]

oo, good question!!  how can you tell?  i can post pics.  right now, i have the clamp on Yankee Hill FSB. the diameter is the .750 

[survivalshop]

6 hours ago, snipernuts said:

oo, good question!!  how can you tell?  i can post pics.  right now, i have the clamp on Yankee Hill FSB. the diameter is the .750 

 Where you purchased the Barrel from or the Manufacturer . 

[shepp]

10 hours ago, snipernuts said:

oo, good question!!  how can you tell?  i can post pics.  right now, i have the clamp on Yankee Hill FSB. the diameter is the .750 

 

3 hours ago, survivalshop said:

 Where you purchased the Barrel from or the Manufacturer . 

There should be spec on it online where you bought it like SS said. kinda silly buy a gas block with no clue of your barrel spec?! 

[snipernuts]

i got these from AR15.com, the barrels were made for spikes from FN, but the contract fell through, what i was told, so, as far as specs, thats all i got.  took some pics, let me know what you guys think

[98Z5V]

You REALLY have to figure out what barrel extension that barrel was built with...  That's something that only you can research, from where you bought it...

[survivalshop]

  The Spikes 308AR's Receivers were built to DPMS standards ( some here have builds using them ), so more then likely its a DPMS type Barrel extension . I have been told , they are very good barrels & I believe they were .750" Gas Block Diameter. Your Gas Block looks odd , or the photo at a bad angle .

You can contact Spikes by email or phone call & they will know .

  Fn made 5.56 Barrels for Spikes also .

[EngrBob]

My first .308 build was on a Spikes upper, and it is DPMS pattern (I married it to a Faxon barrel and it is a tack driver).

[snipernuts]

i just talked to the guy i bought it from, and yes, its DPMS pattern, life is good!!  so with that being said, i'd like to use that Yankee Hill FSB, but, still concerned with how to align the gas orifices up between the barrel and the FSB.   has anyone else done this?  how?

thanks guys!!

 

kup

[ARTrooper]

he said orifices

[DNP]

Thats just for the above post...I didn't chuckle. I swear. 

Edited November 8, 2016 by DNP

[survivalshop]

9 hours ago, snipernuts said:

i just talked to the guy i bought it from, and yes, its DPMS pattern, life is good!!  so with that being said, i'd like to use that Yankee Hill FSB, but, still concerned with how to align the gas orifices up between the barrel and the FSB.   has anyone else done this?  how?

thanks guys!!

 

kup

    The Gas Block you have appears to be a two piece clamp type of attachment ( I don't care for this type of clamp attachment ). It should seat flush against the Barrels , stop flange for the Gas Block . There are a couple ways to align it , one would be to attach the Gas Tube & seat the Gas Block against the Barrels stop , with the gas tube inserted into Upper Receiver & measure the Gas tubes gap on both side of it compared to the Charging Handles Channel in the Upper receiver & center it as best possible .

 Another way is to mark a center line , in line with the Gas Port in the Gas Block , then mark a center line with the Barrels Gas Port & match them up when tightening Block down . A marker should work , mark the top of the bbl. & the face of there Gas Block where it seats on the Barrels stop flange .Acetone or Rubbing Alcohol should remove the marks when done with them . Use LocTite on the screws , blue should work , because you might want to take it off at some point . 

 Should give you enough of an idea of how to set it up , use both methods to check to make sure its centered . 

 You can also measure Gas Port locations , from Gas Port hole in Gas Block to end of Gas Block that seats against the Barrels stop flange & the Barrels Gas Port to the Barrels stop flange for the Gas Block & compare them . The Gas Blocks Port will be larger then the Barrels Port , proper size Drill bit Shanks can be used for measuring reference .

 If your Barrel has a dimple cut into the bottom of it , the Gas Block may have a reference on the bottom clamp to help with alignment & none of the above will be needed .

  

[snipernuts]

I meant gas port....I swear!!