Kano383
Member
I’ve been giving a look at the ballistics of various .45 loads, in standard .45 ACP, in .45 ACP +P, and in .45 Super.
Before starting the discussion, I must say that I have no real interest in the .45 Super per se, but I’m very interested in understanding better how things work in a 1911 - and in guns in general.
Now, as I understand it, the pressure limit for the .45 ACP comes from the unsupported portion of the chamber in the original design.
In barrels with fully supported chambers, the limiting factor becomes the .45 ACP case, which is not designed to handle high pressures.
And here comes the .45 Super, which uses stronger cases, hence can handle higher pressures - pressures that 1911 chambers and barrels can handle without problem, as long as the chamber is fully supported.
Searching for wisdom from those who have gone to .45 Super in 1911, it appears that there is consensus on the need for heavier springs (recoil and FP) to handle the added Oomph.
Now, back to ballistics...
Comparing loads in the three versions, it is apparent that most .45 ACP loads generate between 26 and 30 lbf*s of momentum, +P loads between 30 and 34 lbf*s, and .45 Super between 30 and 40 lbf*s.
The +P range overlaps with the bottom half of the Super range, while the top of the the .45 ACP range stops where the Super starts.
It wouldn’t make much sense, then, to simply say “Use Xx# springs in your 1911 if you want to shoot +P ammo, or .45 Super”, especially seeing that within the .45 Super moniker, you have differences of +33% in momentum between some loads.
So... Is it not a more sensible approach to consider various loads’ momentum, to see what would work in a gun with a particular configuration?
And, important question, is it correct to assume that loads developing the same momentum, regardless of bullet weight or velocity, will work as well as each other in the same gun?
Here is a sample of a few loads for comparison:
Before starting the discussion, I must say that I have no real interest in the .45 Super per se, but I’m very interested in understanding better how things work in a 1911 - and in guns in general.
Now, as I understand it, the pressure limit for the .45 ACP comes from the unsupported portion of the chamber in the original design.
In barrels with fully supported chambers, the limiting factor becomes the .45 ACP case, which is not designed to handle high pressures.
And here comes the .45 Super, which uses stronger cases, hence can handle higher pressures - pressures that 1911 chambers and barrels can handle without problem, as long as the chamber is fully supported.
Searching for wisdom from those who have gone to .45 Super in 1911, it appears that there is consensus on the need for heavier springs (recoil and FP) to handle the added Oomph.
Now, back to ballistics...
Comparing loads in the three versions, it is apparent that most .45 ACP loads generate between 26 and 30 lbf*s of momentum, +P loads between 30 and 34 lbf*s, and .45 Super between 30 and 40 lbf*s.
The +P range overlaps with the bottom half of the Super range, while the top of the the .45 ACP range stops where the Super starts.
It wouldn’t make much sense, then, to simply say “Use Xx# springs in your 1911 if you want to shoot +P ammo, or .45 Super”, especially seeing that within the .45 Super moniker, you have differences of +33% in momentum between some loads.
So... Is it not a more sensible approach to consider various loads’ momentum, to see what would work in a gun with a particular configuration?
And, important question, is it correct to assume that loads developing the same momentum, regardless of bullet weight or velocity, will work as well as each other in the same gun?
Here is a sample of a few loads for comparison:
