Not exactly related to the different barrels,, but it does go hand in hand with this discussion. From another Forum, by a respected handgunner who's got the credentials to back up his information.
"Cylinder length is a long topic. A few basics:
Long cylinder
* Slower BARREL FACE EROSION (commonly called FORCING CONE EROSION, although, there is a technical difference). Applies especially to large charges of slow powder.
* Shorter BARREL TENON STICKOUT (for a giver length window). Support around forcing cone.
* Better combustion with some cartridges cases and powders.
* Accommodates long cartridge case.
* Accommodates long bullets.
Short cylinder
* Less weight, with less iflywheel effect. Rotation accelerates faster, stops with less impact on BOLT (aka stop, cylinder catch), and bolt notch.
* Faster cylinder face erosion.
* Longer BARREL TENON STICKOUT (for a given window).
* Faster BARREL FACE EROSION.
* Claims of improved accuracy with wadcutter target ammo.
Adapting .357 Maximum cylinder to Blackhawk/Super Blackhawk frame
Original prototype .357 Maximum used a New Model Blackhawk frame. (The New Model Blackhawk and NM Super Blackhawk are the same frame.) With a long cylinder to chamber the original 1.490-inch Remington Maximum case. The cylinder crowds the Blackhawk window. Shooting quickly progressed to a stretched frame----the SRM----and 1.605-inch case.
To shorten a .357 Maximum cylinder for the Blackhawk frame and chamber to .45 Colt, chamber-to-bore alignment should be checked, with chambers cut to align with bore. If there is runout and the holes are enlarged concentrically, misalignment will infect the finished chambers. Unless the gunsmith can correct a misalignment issue with the re-chamber, I see no point...
.... unless you have a long bullet of high ballistic coefficient.... Or, you want the look.
David Bradshaw"
"The physics of the difference in BARREL FACE EROSION erosion is not obvious. Assuming cylinder gaps are equal and the "short tenon" is other than completely flush with the cylinder frame as most appear to be. If the tenon were perfectly flush then that effect would be a little easier to grasp.
Whatever the physical property of compared metal, a large gap allows more particles to escape in the rush of combusting powder. My humble reading sees ball propellant more abrasive than stick or flake, but this doesn’t account for such things a s heat and presence or absence of nitroglycerine. Believe want you want. S&W has set back barrels on K and N frame revolvers for this shooter. Ruger, also.
As for the tenon perfectly flush against cylinder window, no thanks. This shooter likes a hub or gas ring for the bearing surface and for gas deflection. The .357 Mag is a great cartridge to demonstrate the slower face erosion from a longer cylinder.
I have no history to validate or refute some PPC claims of superior accuracy of. 38 Special 148 Wadcutter from a short cylinder. Nor have I tried 148 Wadcutter in a Blackhawk .357 Maximum----which shoots .38 Special JHP and .357 Mag JHP very well.
David Bradshaw"
"Sideblast is more fierce from the shorter cylinder.
As for the 11-degree forcing cone, it's been standard at S&W and Ruger since water ran downhill. Any “custom” 11-degree cone adopts an industrial standard. Doubt there is any magicc to the 11-degree included-angle cone; it’s a compromise to accommodate a bit of chamber-to-bore misalignment, while keeping the cone short. Also, don’t forget the ROOT DIAMETER of the FORCING CONE. For a given root diameter, a low-angle cone is cut deeper. For forty years, major manufacturers have screwed up forcing cones. All by itself, an off-axis, rough, or too-deep forcing cone can ruin the accuracy of a beautiful barrel.
Cylinder gap ranks low on the accuracy scale, well below the much ballyhooed crown. Were the ORCHESTRA of DIMENSIONS which compose REVOLVER ACCURACY described as a mountain, I would stack it from the peak...
* bore & rifling.
* forcing cone.
* chambers.
* chamber-to-bore alignment.
However, since accuracy is an Rochester of dimensions, the parts influence the whole in different ways, based upon individual relationships. Brilliant performances have been turned in with S&W, Ruger, and Dan Wesson Arms, and the Colt Python, each with noticeable tenon protrusion into the cylinder window. The drawback to tenon stickup is when the tenon wall is thin and subjected to 1) high pressure, 2) heavy bullets, 3) chamber-to-bore misalignment, or 4) all of the above.
If a shooter likes the look of a long cylinder, that is enough. To reduce wear on the barrel face from high pressure, tall powder charge, or hot powder, the long cylinder helps.
TTP (Time to Peak, or Time to Pressure)
We do not get to watch the burning curve of the loads we shoot. We do know a pressure CURVE is better than a pressure SPIKE. The more combustion laps into the cylinder gap, the more it acts like a cutting torch. If the powder contains nitroglycerine (double base powder), it acts like the oxygen trigger on an acetylene torch. Thus, a short cylinder exposes the barrel face to more torch.
David Bradshaw"
