Want to build an upper but...?

HA556 · Apr 23, 2020

I found this video and there seems to be some things missing. This looks pretty simple to do but, I notice this gentleman doesn't check head spacing so, is that something that is not necessary with newer technology?

And I apologize in advance as I'm not a gunsmith and usually buy my uppers already pre-assembled.

3MTA3 · Apr 23, 2020

HA556 said:
I found this video and there seems to be some things missing. This looks pretty simple to do but, I notice this gentleman doesn't check head spacing so, is that something that is not necessary with newer technology?

And I apologize in advance as I'm not a gunsmith and usually buy my uppers already pre-assembled.

I check it, but the AR bolt will fit perfectly in the AR barrel & barrel extension if all three are made to spec. The upper receiver isn't directly part of how the bolt fits since the bolt lugs fit into matching portions of the barrel extension.

Geardo · Apr 23, 2020

HA556 said:
I found this video and there seems to be some things missing. This looks pretty simple to do but, I notice this gentleman doesn't check head spacing so, is that something that is not necessary with newer technology?

And I apologize in advance as I'm not a gunsmith and usually buy my uppers already pre-assembled.

If you buy a barrel from ar15performance.com you have the option to include a headspace matched bolt.

titsonritz · Apr 23, 2020

HA556 said:
This looks pretty simple to do but, I notice this gentleman doesn't check head spacing so, is that something that is not necessary with newer technology?

It is something that is not necessary when using known quality parts that are within spec. Per TM 9-1001-319--23&P the only gauge used to check headspace is a field gauge...here is the civy version
BROWNELLS 5.56MM MAXIMUM HEADSPACE GAUGE | Brownells
...but that is used to check for excessive wear.

nk02442 · Apr 23, 2020

Anyone can slap some parts together. Most don't have a problem with it.

If you have the tools , Knowledge AND use the right parts you can build a fine AR. Lots of junk parts guns out there are nothing but ticking time bombs.

Its cheaper to buy a quality factory gun if you don't possess the above.

This is coming from someone who has build these guns for 20+ years. To do it right takes time and money.

HA556 · Apr 23, 2020

Taco_lean said:
If you buy a barrel from ar15performance.com you have the option to include a headspace matched bolt.

Wow, thanks for that very useful information. Going to check them out now. :s0155:

titsonritz · Apr 23, 2020

3MTA3 said:
I check it, but the AR bolt will fit perfectly in the AR barrel & barrel extension if all three are made to spec. The upper receiver isn't directly part of how the bolt fits since the bolt lugs fit into matching portions of the barrel extension.

Which a function of the barrel manufacturer, not an assembler.

HA556 · Apr 23, 2020

nk02442 said:
Anyone can slap some parts together. Most don't have a problem with it.

If you have the tools , Knowledge AND use the right parts you can build a fine AR. Lots of junk parts guns out there are nothing but ticking time bombs.

Its cheaper to buy a quality factory gun if you don't possess the above.

This is coming from someone who has build these guns for 20+ years. To do it right takes time and money.

You've got my attention!

I'm just feeling this out for now and if it is more than I can chew, I'll stick to my original steps and buy them already assembled. :s0155:

nk02442 · Apr 23, 2020

titsonritz said:
It is something that is not necessary when using known quality parts that are within spec. Per TM 9-1001-319--23&P the only gauge used to check headspace is a field gauge...here is the civy version
BROWNELLS 5.56MM MAXIMUM HEADSPACE GAUGE | Brownells
...but that is used to check for excessive wear.

The only known quality parts to spec are made by Colt. Everyone else is has either tried to reverse engineer the parts or is taking a guess. FN can't use TDP on commercial guns and neither can LMT (back when they had portion of mk18 contract).

Mil Spec and TDP don't really mean bubblegum to anyone not wearing a uniform and in the ordinance department.

nk02442 · Apr 23, 2020

HA556 said:
You've got my attention! I'm just feeling this out for now and if it is more than I can chew, I'll stick to my original steps and buy them already assembled.

There is alot of measuring and some handwork to get a parts gun build correctly, trued and it requires some special tools. That is to do it CORRECTLY.

Anyone can slap parts together and get the gun to go bang. There are hundreds of things that can and will go wrong eventually, but most people shoot less than 100 rnds a year at dirtpiles and don't actually understand their gear.

Let me know what you are looking for and maybe I can recommend something. Its very very hard to beat Colt and BCM for the money. Buy a factory upper and lower and slap together (which saves you the FET as well). For something higher end, the SR15 cannot be beat. It truly is the pinnacle of the AR15 platform.

If you really want to try your hand at a build, I can recommend some factory parts that are known quantities (BCM uppers, DD barrels, Giselle Rails & Triggers, KAC small parts and Colt Lower parts kit, BCM/COLT/LMT M16 Carriers, ect)

Quality costs money no way around it. Really hard to beat a Colt 6721, throw on a G rail and gas block, Add a G2S trigger, and put an Aimpoint Pro on top. $1800 or so for a first class rifle system that will not only appreciate in value but you can trust your life to.

CLee0507 · Apr 23, 2020

nk02442 said:
The only known quality parts to spec are made by Colt. Everyone else is has either tried to reverse engineer the parts or is taking a guess. FN can't use TDP on commercial guns and neither can LMT (back when they had portion of mk18 contract).

Mil Spec and TDP don't really mean bubblegum to anyone not wearing a uniform and in the ordinance department.

The TDP has been out there for a long time. I am absolutely sure folks like BCM, LMT DD along with others have and use the TDP. Milspec isn't even a something one should care about since the only "Milspec" "AR-15's" are machine guns used in the military.

titsonritz · Apr 23, 2020

nk02442 said:
The only known quality parts to spec are made by Colt. Everyone else is has either tried to reverse engineer the parts or is taking a guess. FN can't use TDP on commercial guns and neither can LMT (back when they had portion of mk18 contract).

Mil Spec and TDP don't really mean bubblegum to anyone not wearing a uniform and in the ordinance department.

That is true, but some do it better than others and has mention above the TDP isn't some big secret.

3MTA3 · Apr 23, 2020

titsonritz said:
Which a function of the barrel manufacturer, not an assembler.

Exactly - I use the gauge to double check the barrel. Never had an issue, but I've never bought cheap, either.

nk02442 · Apr 23, 2020

NO it hasn't. The actual TDP is a trade secret and only shared with those under contract from DOD and FMS for the purpose of building rifles/componets.

And it doesn't matter if LMT,. DD or FN have the TDP, they cannot use it to build commercial guns. Period.

Geardo · Apr 23, 2020

nk02442 said:
There is alot of measuring and some handwork to get a parts gun build correctly, trued and it requires some special tools. That is to do it CORRECTLY.

Anyone can slap parts together and get the gun to go bang. There are hundreds of things that can and will go wrong eventually, but most people shoot less than 100 rnds a year at dirtpiles and don't actually understand their gear.

Let me know what you are looking for and maybe I can recommend something. Its very very hard to beat Colt and BCM for the money. Buy a factory upper and lower and slap together (which saves you the FET as well). For something higher end, the SR15 cannot be beat. It truly is the pinnacle of the AR15 platform.

If you really want to try your hand at a build, I can recommend some factory parts that are known quantities (BCM uppers, DD barrels, Giselle Rails & Triggers, KAC small parts and Colt Lower parts kit, BCM/COLT/LMT M16 Carriers, ect)

Quality costs money no way around it. Really hard to beat a Colt 6721, throw on a G rail and gas block, Add a G2S trigger, and put an Aimpoint Pro on top. $1800 or so for a first class rifle system that will not only appreciate in value but you can trust your life to.

Hmmm. I agree with the spirit of what you said, but I disagree with some specifics.

The 2nd AR I built Has had 5-10k rounds through it, all full power m193, quite a bit of mk262, and the majority with a 5.56 suppressor on it. Its going fine. Still accurate. Still runs great. I don't dump mags in the dirt but I run my guns hard doing drills.

The tools to build these guns are pretty simple, unless you are installing an FSB on your own?

I agree a first gun should be from a known good factory, but no reason not to DIY the 2nd or third as long as you have some mechanical aptitude and use high quality parts.

What tools and parts are you specifically referring too?

CLee0507 · Apr 23, 2020

T

nk02442 said:
NO it hasn't. The actual TDP is a trade secret and only shared with those under contract from DOD and FMS for the purpose of building rifles/componets.

And it doesn't matter if LMT,. DD or FN have the TDP, they cannot use it to build commercial guns. Period.

The TDP is a living, breathing spec., it has changed with time. My point is there is known tolerances covered by the TDP and any good quality manufacture adheres to it. Colt has sometimes outsourced components that adhere to that spec, it is a known spec and other manufacturers do as well.

Colt gets a royalty for every M4 made by whoever is contracted by the military. The TDP cannot be used for commercial sale because that is the contract, not because its a big secret.

3MTA3 · Apr 23, 2020

Yikes - the OP just wants to build an upper and had a simple question. Somehow we opened a rift in time and space continuum of the forum dimension big enough to let a fair amount of m4carbine.net dogma leak in.

"I hearby banish thee salesmen moderators back to the horsey roll marks of m4carbine.net!" (did that work? I didn't think so)

Yes crappy (or even non crappy) parts crappily assembled will work like crap. Understood. Even with the mighty TDP, Colt lost the M4 contract to FN due to quality issues. Yeah, they did eventually get half of it back. The AR platform is a well designed machine that can be properly assembled by anyone who has a few specialty tools (that every owner should have to perform proper maintenance and repair), who takes their time and doesn't cut corners. No magic here. It's a machine and parts are parts.