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Discussion Starter #1 (Edited)
Dear all,

what is the correct value of B/C gap and the correct value of endshake on super redhawk 44 mag?

in my gun:

B/C gap is 0,004"

considering that the total gap is 0,008" , the endshake is 0,004"


What do you think about them? Are they correct or are too much?

thank you for your suggest!
 

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in my gun:

B/C gap is 0,004"
.004 is fine, my RH has .005 and works great.
Count yourself fortunate. I've seen factory gaps at .009.
There is a slight velocity loss as the gap increases.
 

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usually as the end-shake increases the gap diminishes. I had to install endshake washers in an old Smith once. The B/C gap became .000 and the endshake was .008. I installed 3 .002 endshake washers that increased the gap to .006 with .002 endshake. This was a perfect fit and freed up my cylinder from binding.
 

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Discussion Starter #4
thanks for the suggestion,

i am not so shure if the rings bearing are useful in my case.
What do you think? it is the time or is better to wait the increasing of the gap?
 

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If yours is functioning properly, I'd leave it alone.
 

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Giovanni.... if the an .008" feeler gauge is the thickest you can insert between cylinder and barrel----while pushing the cylinder rearward----that is the cylinder gap (barrel-cylinder gap) of your Super Redhawk.

As implied, endshake is the amount of forward/backward movement of the cylinder in the frame window. If endshake exceeds cylinder gap, or is limited by cylinder contact with the barrel, the cylinder will bind on rotation, particularly during double action carry-up, where leverage is less.

Endshake sequence:
1) Firing pin strikes primer, drives cylinder forward.
2) Primer detonates, tries to push itself out of the primer pocket, while pushing cartridge into chamber.
3) Powder charge ignites, pushes bullet forward, cartridge case backward.
4) Gas vents between cylinder and barrel, slams cylinder against standing breech.
5) Quite likely, the cylinder bounces fore and aft in the frame window. The greater the endshake, the greater the bounce, i.e. hammer effect.

Cylinder gap has little influence on accuracy. My guess is that endshake may influence accuracy, but that it would take considerable endshake to notice, and the revolver would have to be super accurate at the start.

Gap, however, dramatically affects velocity. The higher the pressure, the greater the disparity between a tiny gap and a large gap. That, and firm chamber exits, are reasons why Freedom Arms revolvers and high-end custom revolvers turn HIGH velocities when compared to production guns. And this is why it is virtually impossible for a Super Redhawk .454 Casull to approach the velocity of a Freedom Arms .454 shooting the same load.

Your SRH gap of .008-inch is, I believe, within Ruger tolerance. In setting up the Blackhack .357 Maximum for production, Bill Ruger, Jr., found a way to set gap very tight without derailing assembly. A .0015-inch feeler does not fit between cylinder/barrel of my #600-00018 .357 Maximum. Regrettably, the ".357 Maximum technique" for tight fit-up does not seem to have carried over to the regular production line.
David Bradshaw
 

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Discussion Starter #7
David, thank you for the good answer.
do you consider valid the use of endshake washer in my case?
The ruger customer service said that this operation isn't necessary in my case.
What do you think?
regards
 

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Giovanni.... I think you can live with .004" endshake. Wouldn't lose zzzz's over it. Factory service is unlikely to provide you a tolerance package, or to eliminate endshake, as yours probably fits well within those mysterious specs.

Cylinder/barrel gap must be greater than endshake for free rotation. Therefore, endshake must be taken up before the barrel can be set back to reduce gap.

Am not familiar with a procedure for elimination of endshake in the Redhawk and SRH. Old school S&W's are very much a hand-fit design, and stretching the barrel of yoke was routine for refitting or tuning a cylinder. Ron Power developed shims for the Smith, which were used on many PPC revolvers. I expect Ron Power, Hamilton Bowen, and Jim Stroh are intimately acquainted with RH/SRH endshake, and would put your mind at ease, either by fixing or not eliminating endshake.

I am adverse to gizmos on or in my guns, although endshake shims may be trouble-free. One thing that helps prolong service life is good motor oil and chassis grease. That's right, I prefer automotive lubricants, with sparing synthetic for deep freeze weather. Just as synovial fluid lubricates and cushions our joints, so too, good lube cushions steel.

Endshake was reduced during factory tune-ups on several of my S&W's. The Redhawk and SRH are brilliant designs which still require hand fitting. Neither point anywhere near as well as a Model 29, but their mass and metallurgy put them on top in DA durability.
David Bradshaw
 

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Giovanni, Although Ruger doesn't publish their specifications, the established gunsmith endshake spec for all Ruger DA revolvers is a max of .005" and a minimum of .002". B/C gap should be no tighter than .004" and no wider than .008", with .006" being optimum (with the cylinder held fully to the rear). As David Bradshaw stated, the cylinder tends to move fore and aft when the gun is fired. The most violent movement is in the forward direction when the friction of the bullet grabs the cylinder throat and thrusts the cylinder forward with thousands of psi. This will cause the crane tube to eventually peen and will create a channel inside the cylinder center hole where the crane tube makes contact. Using oversized bullets will accelerate endshake because there is more bullet-to-throat friction. No type or amount of oil will prevent peening. Besides, oil will attract powder residue and cause more wear rather than reduce wear and can cause the cylinder to bind up.

Once endshake exceeds .005", the mass of the cylinder starts acting like a battering ram and will accelerate crane tube peening and deepen the channel inside the center hole even faster. Excessive endshake or an excessive B/C gap have very little (if any) impact on accuracy. Each .001" of B/C gap (measured with the cylinder held back) will lose about 1.5% muzzle velocity compared to a closed breach gun. In your case, .008" will lose about 12%, whereas an optimum .006" B/C gap will lose about 9%. In other words, you will lose about 3% more than normal, which would be about 50 fps with a standard 44 Mag factory load.

There are two primary issues with excessive endshake, the first being misfires. As the firing pin strikes the primer, any forward cylinder movement will cushion the primer hit and will cause light primer strikes. If endshake allows enough cylinder movement, light primer strikes will turn to misfires. The second and most important issue is safety. As you may have noted, the cylinder lock notches and the cylinder latch are crescent shaped. Further, the cylinder latch is only held in the lock notches by spring tension. If there is enough forward cylinder movement (endshake) the cylinder latch will cam down and allow the cylinder to break loose. This can be devastating because the cylinder can rotate slightly when it breaks loose and cause the bullet to strike the frame instead of being directed into the forcing cone.

There are two ways to repair excessive endshake. One is to use a special tool that looks much like a tubing cutter. This technique will actually stretch the crane tube, however this "Band-Aid" fix is very temporary because the crane tube will compress again when the gun is fired. The best fix is to install endshake bearings, which are nothing more than very thin washers that are placed between the end of the crane tube and the cylinder center hole mating surface. Before endshake bearings will seat properly, you must use a flat nose rotary grinder and remove the channel that developed inside the center hole. The more rounds that have been fired, the deeper the channel will be. Once the center hole bearing surface has been trued up, the next step is to square up the end of the crane tube. This is done with a facing cutter and must be a very smooth and uniform cut or the cylinder will have tight/loose spots. Of course these two steps will increase endshake even more but it's not a problem because you can stack endshake bearings until the gun is well within specs (.002" is optimum). Once endshake bearings are properly installed, the gun will last longer than it did with the factory setup. Besides, the added washers will allow the cylinder to rotate with less friction.

Because both of the above techniques move the cylinder to the rear, the B/C gap on your SRH will end up being .008", which is the upper limit. B/C gap is regulated by the thickness of the ratchet column. Besides a loss of velocity, wider B/C gaps will "spit" more powder residue and bullet fragments and will cause more flame cutting on the revolver's top strap. This is not a big deal ... just something you have to put up with when a gun starts to wear. Of course you can remove the barrel and trim back the collar exactly .042" (one complete thread). This will seat the barrel .042" deeper so it can be cut back with a facing cutter to change the B/C gap to .004".

Endshake and B/C gap are always a combination of how the gun left the factory and how many rounds of ammo have been fired. If the gun left the factory with a snug B/C gap and endshake, chances are it will hold up for thousands of rounds. Eventually, the B/C gap will widen as the recoil shield and ratchet column get peened and endshake will also widen as the crane tube and cylinder center hole get peened. This is unavoidable in any revolver, however a Ruger DA revolver will hold up much longer than a S&W or any other brand of DA revolver because Rugers are designed with more massive crane (yoke) tubes.

To fix or not to fix ... that is the question. If you plan to shoot this gun a lot with magnum loads, I would keep an eye on endshake. When it exceeds .005", it's time to take some action before the gun becomes dangerous. In it's current state, it is marginally in spec so it would still be safe to shoot. A SRH will hold up much longer if you shoot milder loads like 44 Specials. Just food for thought.
 

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Discussion Starter #11
due to your consideration , i am convinced to install the enshake washers.
I will buy they on midway italy.

Do you know where I can download a instruction/video that shows how to proceed?

Thank you for the good support.
Regards
 

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Discussion Starter #12 (Edited)
hi all,
today I assembled the endshake bearing washer on my SRH. It was a very easy operation and the result is good. Now the endshake is 0.002
thanks to all for the suggests.
tomorrow morning at the shooting range I will try the revolver and some shot also with my marlin 1894 44 magnum, nice carbine!
bye
 
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