Building a Precision AR - Can I do it?

[Tarheelpwr]

So, basically looking to shave a few $$ off my 6.5 Grendel Build. Like everyone, money is tight, esp with a new baby girl. Assuming I buy quality parts, can a buddy with the tools and I put together a quality AR? Parts will look like (only listing main ones):

JP barrel kit; barrel, brake, gas block, thermal diss
Random FF handguard once I decided which will fit over the thermal diss
Daniel Defense A4 Upper
DPMS bolt carrier

Basically, I'm asking if the parts make the build in an AR, or if the smith actually works some magic when he assembles it all? I figured since JP headspaces/matches the bolt to the barrel, most of the "precision work" is done. Anyways, let me know if I could still put a tack driver together myself or if I'm wasting the potential of the system and need to just spring for a smith.

Chris

 

[Jumper]

If the barrel is already chambered and headspace set with the bolt I would say yes. The primary thing left for you to do is properly torque the barrel nut.

 

[LRRPF52]

There are some peculiarities associated with the PPC-based cases in the AR15 for reliability, namely radiusing the ejector face.

Will this be a 22" barrel? JP uses excellent barrels that usually will keep 10 rounds inside of an inch at 100yds.

As far as being able to assemble an AR15, there are people with IQ's of less than 85 that somehow get them together and working. It's a very simple design meant for ease of repair by someone with minimal training.

 

[Tarheelpwr]

I will be going with the 18" barrel. I have no doubt in my ability to get it together. I just want to make sure it runs and runs up to the parts abilities. After all, it's only another 100-200 to get a smith to do it an guarantee it.

 

[LRRPF52]

When I build an upper for precision, there is a laundry list of things I do, including

* trouble-shooting the gas system,
* lapping the bolt to the extension,
* bedding the gas block and barrel extension,
* Cerakoting the barrel, gas block, upper receiver, ejection port door,
* de-edge, blend, and polish the feed ramps
* radius the ejector
* de-horn the extractor if necessary

That's off the top of my head.

 

[Tarheelpwr]

When I build an upper for precision, there is a laundry list of things I do, including

* trouble-shooting the gas system,
* lapping the bolt to the extension,
* bedding the gas block and barrel extension,
* Cerakoting the barrel, gas block, upper receiver, ejection port door,
* de-edge, blend, and polish the feed ramps
* radius the ejector
* de-horn the extractor if necessary

That's off the top of my head.

'

That's the reality I was thinking. I think the most important part of the precision build is the Cerakote Just kidding though. That's for educating me.

 

[bustin]

'

That's the reality I was thinking. I think the most important part of the precision build is the Cerakote Just kidding though. That's for educating me.

If you use a Mega or Vltor receiver the fit will be tight to the barrel extension so you wont need to square the receiver or bed the extension.You may have to tap the barrel into the receiver, that's normal.

 

[Jumper]

Oops! Forgot about lapping the bolt to the extension. Still, its not difficult to do before everything is assembled.

 

[jevan126]

Just get a JP or a GAP and eliminate all the headaches you would have gotten.

 

[Why1504]

I have built one. I used a Shilen barrel and bolt I ordered directly from Shilen. Gun is a one hole puncher. IMO barrel, bolt, ammo, and trigger are the parts to focus on.

 

[Thebelly]

I've assembled 'precision' ARs from parts before. As long as you go slow, figure out what you're doing, and take the time to understand what can make an AR accurate vs. not accurate, then I think you'll be fine.

I use the words 'assembled' and 'precision' with that emphasis on purpose. I didn't create anything, really. I just put the parts together.

 

[Tarheelpwr]

Just get a JP or a GAP and eliminate all the headaches you would have gotten.

If that was an option I wouldn't have started this thread. But yes, that is def a better option.

 

[Tarheelpwr]

How are Black Rain Ordnance billet sets? I stumbled across a billet upper/lower for a .308 I was looking at. It's a different direction, but the price looked right and it's available. Assuming everything else quality, would the BRO be a good shell to start from? I'm looking at a normal black set. I don't know anything about BRO.

 

[Unknown]

After owning a number of different Grendels, and having a number of bolts break the lugs next to the extractor, the last smith to work on my rifles explained something important..

As the Grendel bolt has less material supporting the lugs, any inconsistencies in the face of the upper receiver where the barrel extension meets the receiver can cause problems such as broken bolt lugs. He said that the majority of upper receivers (at least the forged ones, not necessarily those from a billet) have faces on the upper that are not perfectly square with where the barrel extension mates up. He said is is important to square off the upper receiver before installing the barrel.

I presume he was correct, because prior to him squaring up my receivers, I had three broken bolts. I haven't had a bolt break since he squared the receivers. Brownell's sells the tool to square the receivers, and they are a better deal than buying more bolts.

 

[kjoens]

If I can do it anyone can. CLE Krieger 1:7.7 finished at 18.5" with headspaced bolt. Stick it all together with a good trigger and whoala you have a bugholer.

KJ