AR Sponsor
Posted: 2/2/2010 9:02:00 AM EDT
| What is the difference between a square forged upper, and a round one? How do you tell the difference? |
|
So, I've wondered about this for a while.
Is this a night & day shift? Did they suddenly switch from square to rounded? Or is this a byproduct of the forging process, where the mould slowly got worn down in that corner, such that there's really a gradient of early to late (square to rounded)? Are there "transitional" so to speak, uppers, that fall in between? |
|
Quoted:
So, I've wondered about this for a while. Is this a night & day shift? Did they suddenly switch from square to rounded? Or is this a byproduct of the forging process, where the mould slowly got worn down in that corner, such that there's really a gradient of early to late (square to rounded)? Are there "transitional" so to speak, uppers, that fall in between? Likely the made a new forging die when the old one wore out, and that straight line/radius was a non critical dimension, i.e the exact shpae didn't matter. You would not see a die wear that much and still be used. |
|
Quoted: So, I've wondered about this for a while. Is this a night & day shift? Did they suddenly switch from square to rounded? Or is this a byproduct of the forging process, where the mould slowly got worn down in that corner, such that there's really a gradient of early to late (square to rounded)? Are there "transitional" so to speak, uppers, that fall in between? According to Ekie's "USGI Colt 603 XM16E1/M16A1 upper buyers guide Edition II" thread, round forging began showing up in 1966. As to why the change occurred, I've wondered the same thing myself. And I do have what I'd call a "transitional" 604 rounded upper. It's not a true square like the early ones, but it's also far less curved than the "Late" one in the pic that Engineer5 posted. |
AR Sponsor