Rovolver vs. closed breech pressures?

G

Gunn Smithy

New member
For a given load, is it more easily handled in a revolver such as a Ruger Super Redhawk say versus a closed breech system like the TC Encore or Contender due to the gas relief afforded through the barrel/cylinder gap? Or does that have anything to do with it at all? Smithy.
 
Good question,but I think the chamber thickness on the contender,would more than make up for the "pressure release" on the revolver.
 
Locate the sierra 2nd edition manual,...

they have a section on reloading for the contender. Compare those results against the same cartridges used in revolvers.

The 0.004 - 0.006 gap on new revovlers "should" not be significant factor.

Your taking from the side pressure, while still directing the majority of pressure behind the traveling bullet out the barrel.
 
The pressure of a handgun cartridge is contained almost completely in the chamber, or the cylinder of a revolver, so the barrel/cylinder gap has no effect on chamber pressure, but does lower velocity a bit as gas escapes behind the bullet.

Revolver barrels are measured from the front of the cylinder to the end of the barrel, while Contender/Encore barrels are measured from the breech face. So for a 10" barreled Encore, about 1.7" should be subtracted to correspond to a revolver barrel length, so about 8.3". The difference between the velocity of an identical cartridge fired in an 8-3/8" barreled revolver and a 10" Encore would be insignificant.

The advantage of the single shot comes in being able to load bullets farther out, increasing case capacity. I can get the same velocity with a 300 gr bullet out of my 10" Encore that I can from a 240 gr bullet out of my S&W revolver, at the same pressure. The difference is an extra 2 grains of powder space below the bullet.
 
For a given load, is it more easily handled in a revolver such as a Ruger Super Redhawk say versus a closed breech system like the TC Encore or Contender due to the gas relief afforded through the barrel/cylinder gap? Or does that have anything to do with it at all? Smithy.
Click to expand...

You have to look at the load path and how much metal is carrying the load.

Assuming you have enough material to hold all the "hoop stresses" around the case.

A stiffer structure handles loads better than flexible ones.
 
That's like asking if boxers or speedos are better. They're both made to "chamber" the same "cartridge" but do it in their own way. The designs are completely different.
 
The barrel/cylinder gap has nothing to do with how the gun handles pressure. In most cases, full pressure is developed before the bullet passes the gap. What a closed system does is allow full pressure behind the bullet as it travels down the barrel.

A Revolver allows some of the pressure to vent through the gap, but the majority of it pushes the bullet all the way out.

This does nothing affecting how the breech mechanism / cylinder handles the pressure of the round. You can say that the unvented system sustains peak pressure longer, but both systems contain the same peak pressure.

One individual gun might be "stronger" than another, allowing for a higher maximum working load, or a general design might allow a generally higher max.

The books generally list Contender loads a bit stronger than revolver loads, but I have shot ammo from heavy revolvers that was fine in them, but too hot for my Contender! (this ammo was also too hot for lighter revolvers). While general principles apply, there are exceptions.
 
Smithy, I have a question.

What do you mean by "...is it more easily handled ..." ?

Are you asking which mechanism can safely contain more pressure, or which type of arm generates less recoil? Or have I missed the point entirely?

Generally, a longer barrel gives more velocity from the same cartridge loading. However, different examples of the same type of firearm will give different velocities depending on a multitude of internal - almost imperceptible - differences.

Black Mamba correctly cited the problem of 'barrel length'. Holster makers measure barrel length of revolvers from muzzle to face of cylinder, and pistols from muzzle to breach face. Ballisticians measure barrel length by the distance the bullet is actually pushed by the power charge. So ballistics barrel length is from the base of the bullet (where ever it may be) to the muzzle. This means in practical terms a revolver ALWAYS has a ballistic length longer than the nominal length and a pistol (semi-automatic or single shot) ALWAYS has a shorter ballistic length than nominal length.

If the question is pressure containment, SAAMI (Sporting Arms and Ammunition Manufacture's Institute) voluntary standards dictate the operating pressure of a .44 Magnum to be XX,XXX copper units of pressure. So any firearm manufactured by a SAAMI member and marked as .44 Magnum will handle that level of pressure safely. Which is not to say each sample will do so forever. (Feel free to check out

http://www.saami.org/specifications_and_information/publications/download/205.pdf

to see why I'm being vague about the actual numbers.)

Revolvers 'wear out' by some combination of two major factors. The top strap stretches over time and therefore the cylinder develops end play. This gets worse with age. Double action revolvers also develop a bit end play by the crane and the axis of the cylinder getting beat back and forth.

Single shot pistols, like the Contender or Encore, can - over time - shoot loose by means of distorting the holes in the frame being pounded out of round, and/or beating the connecting pin out of shape.

Neither condition typically causes a catastrophic failure where something actually 'blows up' in the classic bits and pieces flying all over creation. More common is excessive headspace where the loaded round will not fire reliably - because the firing pin isn't hitting the primer properly.

I'm not sure there is scientific evidence to show one style gets beat up faster than the other.

Does any of this speak to your question?
 
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