D.W. 357 Maximum cylinder "over throw"?

[HolyHotLoads]

Hi everyone,

I'm hoping someone can shed some light on a problem I'm having with my D.W. 40 silhouette. In double action I will eventually be able to get the cylinder to over rotate the bolt. I noticed it because of some incredibly off set primer strikes, I mean the firing pin was hitting the brass next to the primer! I've only put a few hundred rounds through this pistol as it's new to me but until yesterday I think they were all in single action trying to reach out and touch something and everything was fine. So, its obviously out of time but is it the bolt that needs to be replaced or worked on or the hand or both? I've already stripped it down and cleaned her up. A new cylinder bolt spring perhaps? Any help will be greatly appreciated. Thank you.

*****

billy357.... THROW-BY is manufacture jargon for the occurrence you call “over throw.” You got the mechanical event 100% right, and the lingo half-right.

THROW-BY
Cylinder over-rotates, beyond CYLINDER STOP (a.k.a. bolt or cylinder latch). May occur with both single and double action cocking, and on single and double action revolvers. Generally, throw-by occurs as bolt fails to engage stop notch in cylinder. TIMING (coordination of clockwork & cylinder) may or may not be at issue; a weak or broken STOP SPRING may cause throw-by.

Now, let’s look at the big frame Dan Wesson. The M-40 .357 Maximum is a stretched-frame M-44 .44 Mag. Very strong sixshooter. To pull the stop notch away from the chamber under it, the stop notch is offset to the right. To increase the offset, the stop is angled even more to the right. The top of the stop is angled to match the offset & canted cylinder stop notch. The DWA M-44/M-40 cylinder stop is big and strong. However, its angle of engagement makes throw-by a distinct possibility, even when timing is perfect.The faster you cock the gun, the more likely. You will notice the stop rises through the frame at an angle.

Remedy
With parts stripped from revolver, check fit of cylinder stop in all six stop notches. Fit should be close: not so firm as to resist engagement; not so loose as to wiggle at lockup. A weak stop spring should be replaced. By the nature of its operation, operation of a DA stop is more complex than on a single action.

DWA DA
Double action is an affectation on the large frame DWA. To my mind, the gun is a single action built on a double action frame.
David Bradshaw

[bradshaw]

The exaggerated angle added to the offset CYLINDER STOP resulted in throw-by on some revolvers. Dan Wesson Arms fixed one of mine on a visit to the factory in Monson, Massachusetts. I think it was a Model 40 Super Mag .357 Maximum. Greater mass of the .357 Maximum cylinder may have contributed to occurrence of throw-by on the M-40, as opposed to the M-44 .44 Mag. It’s a shame development of the M-44 & M-40 didn’t reach full refinement, as these revolvers are strong and incredibly accurate.

Jerry Moran, maestro of the Colt Python and IHMSA All-American, spoke yesterday, during which he brought up manufacturing issues at DWA, particularly towards the end and as Dan’s son Seth Wesson took the reigns, along with the shift of manufacture from Monson to Palmer. Moran mentioned problems with chambering, chamber-to-bore alignment, and barrel quality of later guns. None of mine were anything but super-shooters. I did talk with DWA about quality control, competitors returning a new gun for correction, etc. My position was, It must cost less to ship a gun once, than twice.
Your throw-by problem sounds curable, more likely due to conditions mentioned earlier.
David Bradshaw

[HolyHotLoads]

David,

Thank you for your detailed explanation, I appreciate immensely. I will tear her down again tonight and go through the punch list. It is an incredible shooter and as you said I shoot in in single action 98 percent of the time anyway. Its strange, if I pull back on the trigger just the right way I can get the cylinder to spin fast enough to miss SEVERAL chambers! But pulled steady and smooth it seems to be fine. I cant do that with any of my other revolvers. There is certainly a lot of mass in that big ol' cylinder! Thanks again for your reply on this one.

Billy357

[bradshaw]

billy357.... extreme throw-by, as you assert when 2 or 3 chambers pass the stop notch as the revolver is briskly hammer or trigger cocked, adds another point of attention. Check fit of cylinder stop where it rises through frame. Lateral movement should be minimal. Any slop here contributes to cylinder’s ability to skate over stop notches, situation aggravated by beveled stop.
David Bradshaw

[HolyHotLoads]

I was able to tear down the revolver and go through your checklist. The bolt fits the cylinder notches fine as far as I can tell and there is a minute lateral wiggle when in the frame. Upon further study I've come to develop this hypothesis: when first pulling the trigger and watching the hand rise it feels like a trigger pull should. Then, when the hand makes contact with the ratchet it causes what I can only describe as a hitch, then when enough finger power is applied to the trigger(and in turn the hand of course)the cylinder will rotate. So, this hitch is causing excessive energy to develop at the hand and cylinder,which is turned into excessive speed in the cylinder and the cylinder cranks around and the bolt misses. I had never considered end shake into this equation. I'm not sure how to measure end shake on a revolver that has an adjustable cylinder gap, but with the gap set at .002 and using end shake measuring techniques I get .006 of end shake. I've ordered some cylinder shims. So, I am thinking that the excessive end shake is causing the hand to push the cylinder forward and then up rather than up, thus causing the hitch which in turn is causing cylinder to spin 100 miles an hour and causing the bolt to miss. Please forgive the long winded post and if you can point out any flaws in my hypothesis I'd appreciate it.

Thank you,
Billy357

[bradshaw]

Dec 22, 2019 9:50:33 GMT -5 HolyHotLoads said:

I was able to tear down the revolver and go through your checklist. The bolt fits the cylinder notches fine as far as I can tell and there is a minute lateral wiggle when in the frame. Upon further study I've come to develop this hypothesis: when first pulling the trigger and watching the hand rise it feels like a trigger pull should. Then, when the hand makes contact with the ratchet it causes what I can only describe as a hitch, then when enough finger power is applied to the trigger(and in turn the hand of course)the cylinder will rotate. So, this hitch is causing excessive energy to develop at the hand and cylinder,which is turned into excessive speed in the cylinder and the cylinder cranks around and the bolt misses. I had never considered end shake into this equation. I'm not sure how to measure end shake on a revolver that has an adjustable cylinder gap, but with the gap set at .002 and using end shake measuring techniques I get .006 of end shake. I've ordered some cylinder shims. So, I am thinking that the excessive end shake is causing the hand to push the cylinder forward and then up rather than up, thus causing the hitch which in turn is causing cylinder to spin 100 miles an hour and causing the bolt to miss. Please forgive the long winded post and if you can point out any flaws in my hypothesis I'd appreciate it.

Thank you,
Billy357

*****

Good job, Billy. A mind is much better than an attitude at analysis. Much of my education came from the guns themselves, on the Firing Line and off. And LISTENING to sources of experience & knowledge. All based on PUSHING PERFORMANCE. You can’t get there without a TARGET in MIND.

The big frame DWA, the daddy M44 .44 Mag and its offspring M40 .357 Maximum, as with all swing-out double actions, depend on lockup of the YOKE (a.k.a. CRANE) to limit ENDSHAKE. Despite huge differences in execution, there are major conceptual similarities between the Ruger Redhawk and the DWA M44/M40 (and any other model designation of the solid frame Dan Wesson). Cylinder lockup and yoke lockup is tighter, more secure on the Redhawk/Suepr Redhawk, making it easier to limit endshake.

The ENDSHAKES (yoke + cylinder)
The shim which comes with a DWA to set barrel gap should stay in the box. Most DWA shims are .006-inch, with some .002” sent out. The DWA needs an automotive valve adjustment shim set to measure endshake and barrel/cylinder gap. (To shorten it to CYLINDER GAP is fine, as everyone knows what it means.) Gap cannot be set without taking endshake into account

Endshake vs cylinder rotation
What affects gap?
* Fit of yoke to frame.
* Yoke endshake.
* Cylinder endshake.
* Free rotation of cylinder; must not bind.
* Cylinder face square to cylinder axis.

Minimum cylinder gap requires zero yoke endshake + zero cylinder endshake. Difficult to achieve on big frame DWA. Singleactions based on the Colt Peacemaker with their antiquated single loading have only to fit their cylinder to the frame for MINIMUM GAP. Modern metallurgy as instigated by Bill Ruger keeps the single action phenomenally modern, as proven by field users, IHMSA silhouette, and Earthquake Artists led by Dick Casull and John Linebaugh. It is a near miracle, how Smith & Wesson and, Later, Dan Wesson Arms, held near-zero CHAMBER-to-BORE ALIGNMENT with swing out cylinders on a production basis. Ruger paid visits to this lofty ideal, but no-one held it with such tenure as S&W. If DWA had provided the big frame M44/M40 with a slack adjustment to eliminate yoke endshake, the revolver would rack higher velocity, with fewer spitting problems.

THROWBY on the M40
A .357 Maximum cylinder is heavy because it is built to take pressure. To set it in motion takes a push. To stop it takes a good brake----the cylinder stop. The offset stop notch, in conjunction with angled cylinder stop----beveled on top----presents shallow engagement on the stopping side of the cylinder stop. The slanted arrangement of the whole affair invites throwby. There is only so much spring g you can apply to a double action cylinder stop before it misbehaves. Whether the drag you feel as the hand (pawl) initiates rotation is due to cylinder inertia, or to drag of cylinder face against barrel face, I cannot say. But you can.

As you surmise, the hand pushes the cylinder forward as it starts to rotate, which multiples resistance. Also, I happen to think the DWA requires more leverage to rotate than a Colt, S&W, or Ruger double action. More noticeable in DA, as single action cocking uses a longer stroke to advance the cylinder the same 60-degrees.
David Bradshaw

[HolyHotLoads]

David,

Thanks once again for your insight. The cylinder is not dragging on the barrel face. I'm starting to think that what I'm experiencing is normal operation of a DW 40 that has been well used. I will see what happens when I install the shim(s). I will order a spring kit and give it fresh springs and take it from there.
One thing I didnt understand is what you said about endshake needing to be taken into consideration for proper barrel gap. Did you mean that in order for the cylinder not to bind up in a revolver with significant endshake, you need to now how much movement you are dealing with before you set it? Or is there another equation I'm missing? I do use a set of automotive shims to measure cylinder gap, my revolver did not come with a shim.

Thanks again.

[bradshaw]

Dec 22, 2019 15:27:14 GMT -5 HolyHotLoads said:

David,

Thanks once again for your insight. The cylinder is not dragging on the barrel face. I'm starting to think that what I'm experiencing is normal operation of a DW 40 that has been well used. I will see what happens when I install the shim(s). I will order a spring kit and give it fresh springs and take it from there.
One thing I didnt understand is what you said about endshake needing to be taken into consideration for proper barrel gap. Did you mean that in order for the cylinder not to bind up in a revolver with significant endshake, you need to now how much movement you are dealing with before you set it? Or is there another equation I'm missing? I do use a set of automotive shims to measure cylinder gap, my revolver did not come with a shim.

Thanks again.

*****

Billy.... if yoke endshake exceeds cylinder gap, cylinder will drag on barrel when yoke is forward. Both cylinder endshake and yoke endshake prevent minimal cylinder gap. ENDSHAKE usually refers the fore & aft cylinder movement only. Because of the adjustable cylinder gap on a Dan Wesson and the way the yoke is secured in the frame, the yoke must be taken into account.

The fast locktime Dan Wesson demands leverage to rotate cylinder. Once that flywheel is set in motion, it wants to keep rolling. As for double action pull, smoothness depends on smooth movement of DOUBLE ACTION FLY on trigger. I think the big frame DA is an excellent design, poorly executed. The DW trigger and hammer cannot handle long term wear the way the old S&W case hardened parts do, nor Ruger’s through-hardened DA hammers & triggers. A properly set DWA single action letoff should last nearly forever; not so, its double action arrangement.

I treat Dan Wessons as a single action revolver with a swing out cylinder. If you want to shoot a deer double action, have at it, but not with that revolver. I’ve shot whitetail double action with the Model 29 and consider it a stunt. The gun can be carried into the wild anywhere, which cannot be said of DA-only competition revolver at the height of its glory. The rule applies triple in the North Country. A good DWA should be prized for what it is, not what it’s not. Of all the Dan Wessons which have paraded through the winner’s circle in silhouette, it must be a rare one indeed which has been fired double action once.

I trust when you get on it single action you will report back that throw-by is a thing of the past.
Good shooting,
David Bradshaw

[HolyHotLoads]

David,

Roger that. I appreciate all your help on this. Sometimes a man spends to much time picking out the idiosyncrasies of a firearm when he should be out at the range or in the woods trying to master it. I am impressed by this revolver regardless.

Thank you,

Billy357

[oddshooter]

I want to thank both you gentlemen for an excellent discussion of a superb revolver.

Prescut

[bradshaw]

Dec 23, 2019 12:41:38 GMT -5 oddshooter said:

I want to thank both you gentlemen for an excellent discussion of a superb revolver.

Prescut

*****

I trust we never stop learning. I was using a shovel this morning. Wish it was a magic shovel... I’d dig up some great individuals, sit them down by the fire.... and listen.
David Bradshaw

[awp101]

Dec 23, 2019 15:04:34 GMT -5 bradshaw said:

I trust we never stop learning.

The day I stop learning something is the day they'll need a shovel for me.

[HolyHotLoads]

That very thing is what attracts me to the sport of shooting and learning the art of marksmanship. There is an enormous amount of knowledge so vast that one can never quite fully absorb, as it has such numerous facets it would take multiple lifetimes to do so. Techniques and formulas passed down through time, gleaned from lessons learned the hard way. The question isn't how deep the rabbit hole is, but rather how far down are you willing and able to go? And it's available to anyone with humility and an ear(or two).

Plus, things that go bang are cool.