A3 upper receiver vs A4 upper receiver

[OmOpLaTa]

I recently got a 24" Luth-AR upper receiver and it came with an A3 receiver. From the research I've done online, I've found that the A3 receiver is the same as an A4 receiver except it has rifle cut feed ramps vs M4 feed ramp. Is there a benefit to having an A3 receiver with a barrel that has M4 feed ramps?

 

[AR15barrels]

You want the feedramps to match.

The absolute worst setup is rifle feedramp extension in an M4 cut receiver.
The absolute best setup is M4 cut extension in an M4 cut receiver.

 

[OmOpLaTa]

You want the feedramps to match.

The absolute worst setup is rifle feedramp extension in an M4 cut receiver.
The absolute best setup is M4 cut extension in an M4 cut receiver.

I've seen this photo and I completely understand it. But what is the benefit/reason/advantage of having an A3 upper receiver with a barrel with m4 feed ramps? Was it just a matter of cost during assembly? I don't want an "okay" feed ramp system, I'd rather be in the "good" category.

 

[NedSled]

I've seen this photo and I completely understand it. But what is the benefit/reason/advantage of having an A3 upper receiver with a barrel with m4 feed ramps? Was it just a matter of cost during assembly? I don't want an "okay" feed ramp system, I'd rather be in the "good" category.

The reason is that whoever made the upper just did not give a .

It's really that simple.

 

[OmOpLaTa]

The reason is that whoever made the upper just did not give a .

It's really that simple.

If you don't know, just say so.

It's actually a pretty good upper for the price I paid for. 24" fluted 416 SS bull barrel with 5R rifling, brass ejects at 3 o'clock consistently.

Here is a link to the upper:

24″ .223 Rem Bull Barrel Complete Upper Barrel Assembly – Luth-AR

luth-ar.com

It is sub MOA with Hornady Superformance 75 grain ammo. I've seen some companies make complete uppers with barrels that have M4 feed ramps paired with upper receivers with rifle receivers.

 

[NedSled]

If you don't know, just say so.

It's actually a pretty good upper for the price I paid for. 24" fluted 416 SS bull barrel with 5R rifling, brass ejects at 3 o'clock consistently.

Here is a link to the upper:

24″ .223 Rem Bull Barrel Complete Upper Barrel Assembly – Luth-AR

luth-ar.com

It is sub MOA with Hornady Superformance 75 grain ammo. I've seen some companies make complete uppers with barrels that have M4 feed ramps paired with upper receivers with rifle receivers.

I do know the answer. It's the one I gave.
Either they give a enough to properly match components or they don't. There is NO 4-D chess "hidden benefit" for them doing this.

If you want a little more detail, it was one of 2 underlying things:

1) When they planned this offering out, they didn't think about the feed ramps when they ordered/built parts inventory and thought, "meh, good enough" when (or if) they realized the mistake

2) They had a buncha parts in stock, decided to make a packaged offering out of them in the form of this upper, and same "meh good enough it's 'ok' based on that picture floating around the internet" when (or if) they noticed the mismatch.

 

[OmOpLaTa]

I do know the answer. It's the one I gave.
Either they give a enough to properly match components or they don't. There is NO 4-D chess "hidden benefit" for them doing this.

If you want a little more detail, it was one of 2 underlying things:

1) When they planned this offering out, they didn't think about the feed ramps when they ordered/built parts inventory and thought, "meh, good enough" when (or if) they realized the mistake

2) They had a buncha parts in stock, decided to make a packaged offering out of them in the form of this upper, and same "meh good enough it's 'ok' based on that picture floating around the internet" when (or if) they noticed the mismatch.

If you don't know the difference between an A3 and A4 upper, don't feel ashamed. There's a lot of folks online writing hogwash opinions about topics they don't know much about. IMHO your answer is somewhat weak and lacking in expertise (I was expecting to read something more knowledgable and noteworthy). Obviously, you're not a rep of Luth-AR so unfortunately you don't know much about their assembly methods. I appreciate the help though.

 

[NedSled]

If you don't know the difference between an A3 and A4 upper, don't feel ashamed. There's a lot of folks online writing hogwash opinions about topics they don't know much about. IMHO your answer is somewhat weak and lacking in expertise (I was expecting to read something more knowledgable and noteworthy). Obviously, you're not a rep of Luth-AR so unfortunately you don't know much about their assembly methods. I appreciate the help though.

Word.

 

[AR15barrels]

I've seen this photo and I completely understand it. But what is the benefit/reason/advantage of having an A3 upper receiver with a barrel with m4 feed ramps? Was it just a matter of cost during assembly? I don't want an "okay" feed ramp system, I'd rather be in the "good" category.

That is my photo compilation created by myself in 2008 to explain feedramps.

There is zero benefit to the customer having M4 feedramps in the barrel but not in the receiver on a rifle gas system 20" or 24" barrel.
It's a sub-par product produced at a lower price.
The benefit of using less-expensive parts is lower cost to the manufacturer.

To better understand the A1/2/3/4 designations, you have to go back to where they came from:
M16A1: Light weight 20" barrel with a fixed carry handle receiver and safe-semi-full auto operation.
M16A2: Medium weight 20" barrel with a fixed carry handle receiver and safe-semi-burst operation.
M16A3: Medium weight 20" barrel with a flattop receiver and safe-semi-full auto operation.
M16A4: Medium weight 20" barrel with a flattop receiver and safe-semi-burst operation.
M4: Medium weight 14.5" barrel with a flattop receiver with enhanced feedramps and safe-semi-burst operation.
M4A1: Heavy weight 14.5" barrel with a [COLOR=rgb(18, 20, 22)][COLOR=rgb(18, 20, 22)][COLOR=rgb(18, 20, 22)]flattop receiver with enhanced feedramps and safe-semi-full auto operation.

M16A3 and M16A4 both have 20" barrels and rifle length gas systems.
20" barrels have rifle feedramps which are only cut into the barrel extension.
Therefore, the receivers do NOT have extended feedramps like an M4 carbine.
M4 carbines have extended feedramps in both the receiver and the barrel so make them feed reliably at the higher rate-of-fire that the shorter carbine gas system creates.[/COLOR][/COLOR][/COLOR]