Why did stoner put a angle on rear of upper reciever?

[Mj30wilson900]

Why did stoner put a angle Instead of the radius on the upper receiver of the ar10?
Trey Knight made a reference about their being a specific reason for it in a podcast I listened to but never got into it further. I am just wondering if anyone knows the why.
Did dpms put a radius cut to get around patents or something? Why did they design theirs different?

 

[...]

where specifically on the receiver are you talking about?

 

[Mj30wilson900]

where specifically on the receiver are you talking about?

At the rear of the upper on the ar 10

 

[Son of Dorn]

where specifically on the receiver are you talking about?

I'm presuming OP is asking why some Stoner-designed rifles (i.e., the OG AR-10s and the KAC SR-25/M110) have an angle at the back of the upper receiver versus the curve-ended upper of the AR-15 series.

"Sudanese" AR-10

vs

OG AR-15

Why they were designed like that, I haven't a clue.

 

[_Windrider_]

Probably had a lot to do with the machines and tooling at the time.

 

[...]

ah yes, just noticing now he was talking about the AR10.

so im not an expert in the AR10......but looking at it, i can only assume he did so to add more strength to the rear of the lower

a "chamfer" in that corner leads to more material that a "fillet" would, which strengthens the buffer tube threads....so perhaps he was worried about the aluminum in that area dealing with the higher recoil of the .308?

 

[Mj30wilson900]

ah yes, just noticing now he was talking about the AR10.

so im not an expert in the AR10......but looking at it, i can only assume he did so to add more strength to the rear of the lower

View attachment 7512820

a "chamfer" in that corner leads to more material that a "fillet" would, which strengthens the buffer tube threads....so perhaps he was worried about the aluminum in that area dealing with the higher recoil of the .308?

Trey mentioned that it had something to do with Strength so that seems like a logical idea.

 

[TheGerman]

How are you attaching the buffer tube to the lower without that curve?

 

[Mj30wilson900]

How are you attaching the buffer tube to the lower without that curve?

Screw it in from the rear like usual. Nothing changes there.

 

[HenryTheAce]

Screw it in from the rear like usual.

 

[TheGerman]

Screw it in from the rear like usual. Nothing changes there.

Well the buffer tube screws into that reinforced curve. It's the only way to get the buffer in line with the bolt inside the upper.

So its kind of a two-for reason; he had to get the buffer tube from the lower to be high enough to meet the upper, and it needed to be reinforced to take the bolt/buffer both flying back and forth.

A curve also has a stronger/better positioned fulcrum than a straight cut line. I'm sure someone who actually knows about engineering can explain that better.

 

[TheHorta]

You’re really asking why a dude named “Stoner” did something a certain way?

 

[Mj30wilson900]

You’re really asking why a dude named “Stoner” did something a certain way?

Well if he had a cool first name like max or something other than Eugene as that fact really offsets the stoner!
Just kidding all you Eugenes out there.

 

[Bart]

JFC!
Well done, sir.....well done.

 

[MPD142]

Why did stoner put a angle Instead of the radius on the upper receiver of the ar10?
Trey Knight made a reference about their being a specific reason for it in a podcast I listened to but never got into it further. I am just wondering if anyone knows the why.
Did dpms put a radius cut to get around patents or something? Why did they design theirs different?

Currious what podcast this was? I wouldn't mind checking it out.

 

[...]

so one thing a lot of people dont realize is that there is a lot less "engineering" in most products than they realize....

i hear this all the time, " oh the engineers made it that way for a reason"....well...sure...but its not always to optimize performance.

a lot of times things are made the way they are to optimize manufacturability...
a lot of times it done that way to cut cost...
and a lot of times they made it that way because the engineer liked the way it looked...

running any type of analysis is time consuming....and expensive....especially back in the day when it all had to be done by hand.

so what engineers rely on is rules of thumb....rely on previously done designs....and often times rely on overbuilding products.

if a full engineering analysis was run on every aspect of a given product....you wouldnt be able to afford it...

so like i mentioned earlier, im guessing Stoner designed it like that to add material to reinforce the lower....ide be surprised if there was much significant engineering that went in to that.....if anything, im guessing it was more a case of "eh, that looks about good"....

why did DPMS change it?.....i cant say......it could be they were basing their design on scaling up an AR15, so they copied that curvature...it could be so they could use existing tooling.....it could be they liked the way it looked better.

 

[MK20]

If all the cars I have worked on are any indication, engineers rely on being out of touch with the real world and slightly retarded.

 

[Mj30wilson900]

Currious what podcast this was? I wouldn't mind checking it out.

I believe it was the q and a podcast with Kevin brittingham
Episode 5 is where he talks with Trey knight at knights armament