cylinder "lock up"

[J. Yuma]

both my SBH, and SRH revolvers have perceptible cylinder "rotation" when I hold the hammer cocked and trigger depressed, (which I read was a proper way to test lockup?)

Surprisingly, my Pietta .45, and my Heritage .22 do not have any noticeable rotation.
I asked a gunsmith about the SBH, he said "eh."

Any comments?

 

[arfmel]

Perceptible rotational play may not be worth worrying about. Measurable play more likely would be.
Some brand new revolvers have more than others. With enough use, most revolvers will develop some.

 

[NikA]

"Hold the hammer cocked and trigger depressed" doesn't sound correct to me. Moment of firing is trigger depressed, hammer fallen from cocked position. IME, lockup can be different between these two conditions.

 

[J. Yuma]

"Hold the hammer cocked and trigger depressed" doesn't sound correct to me. Moment of firing is trigger depressed, hammer fallen from cocked position. IME, lockup can be different between these two conditions.

ok, I'm on the road right now, but will try again with hammer "halfway home."

 

[arfmel]

Try it with the trigger held back and hammer all the way down.

 

[Sugar River]

Try it with the trigger held back and hammer all the way down.

This!
In other words: as if the gun has just fired but the trigger has NOT been released.

 

[rugerguy]

thats "correct" hammer down ( forward/fired) and the trigger held back, this is "in battery"...........its about all locked up as can be......

 

[J. Yuma]

This!
In other words: as if the gun has just fired but the trigger has NOT been released.

nope, SRH still has a bit o' wiggle

 

[gnappi]

My method... one foot off the ground, elbows extended like the chicken dance, hammer cocked, pull trigger and don't release it and ease the hammer down.

Maybe the one foot off the ground and chicken wing elbows extended is not needed?

 

[J. Yuma]

I could try that.
I think your message is that I'm obsessive compulsive.
A revolver reminds me of a WW2 radial engine, like a Wright Cyclone or a Pratt and Whitney Wasp.
I read somewhere that these engines were basically trying to destroy themselves, and worked well in spite of the physics involved.
So it seems with big bore revolvers...

 

[rkrcpa]

I don't believe holding the trigger back on a Ruger proves anything. That method is for checking a Colt action where the hand bears against the ratchet under pressure from the trigger.

 

[Fox Mike]

Just for S&G I tried the trigger back after firing on my SP 101. There is a very slightly perceptible cylinder movement, that I have absolutely no worries about.

 

[J. Yuma]

as shall I.
case closed.
onward.

 

[stonebuster]

"eh"

 

[Hondo44]

The slight movement is by design: it allows the bullet to align itself with the bore as it enters the forcing cone. You only want zero play if the gun is line bored.

Do a search. There's several discussions on this forum explaining it.

 

[J. Yuma]

like a Harley bottom end, or the pinion gear mesh on rear wheel drive car!
All sliding, rubbing, or rotating bearing surfaces have play.
dunno why I couldn't figure that out.
thanks!

 

[larry8]

The rotational and axial play should be absolute minimum amount as measured like the method above.

 

[J. Yuma]

The rotational and axial play should be absolute minimum amount as measured like the method above.

this was today with the Super Blackhawk, maybe a little play is ok?

 

[DGW1949]

I don't believe holding the trigger back on a Ruger proves anything. That method is for checking a Colt action where the hand bears against the ratchet under pressure from the trigger.

What he said.

As to the OP's observation relative to his Pietta being "tighter" than his Ruger, it's been my observation that Italian 6-shooters often display a very high level of fit 'n finish....On the other hand, American lean-manufacturing?...not so much.

DGW

 

[J. Yuma]

The slight movement is by design: it allows the bullet to align itself with the bore as it enters the forcing cone. You only want zero play if the gun is line bored.

Do a search. There's several discussions on this forum explaining it.

Whelp, I did a search as per your suggestion. It turns out that my analogy to an aero radial engine might be spot on, that being: it works, don't it?

here's the most interesting post (IMHO)
"...incorrect assumption here is that a revolver with no cylinder movement is more accurate, and somehow better and more reliable once all this work has been done. Not so - in my personal experience. Not only that, but normal use will easily wear in those carefully selected parts because they are small bits of metal that cannot withstand many rounds of hot ammunition without deformation. A number of experienced revolver smiths have weighed in on this topic on this very forum. They have repeatedly pointed out that the cylinder and forcing cone are self-aligning if there is a small amount of play in the cylinder.

Furthermore, the claims are that alignment problems are eliminated. Also incorrect. Fussing with pawl thickness and hand thickness might result in one or possibly two chambers lining up exactly. But since there are boring tolerances on the chambers, you have just produced a revolver that "locks up tightly" but incorrectly on all the other cylinders. The only exceptions to this manufacturing reality are when the chambers are line bored with the barrel axis at the cylinder's lockup position. And only a few manufacturers do it that way and at a hefty cost.

One more consideration - reliability. All our careful fitting and choosing of parts down to the last .001" to achieve this amazing no movement lockup situation has to result in greater sensitivity to dimensional changes related to heat as well as sensitivity to powder fouling and debris. That translates into intermittent problems with that action. So where does that leave us?

We know the main critical parts of the revolver that must be right for the gun to shoot. Of primary importance is having the cylinder face parallel to the forcing cone face. And having a smooth and correct angle on that f/c. A nice crown will improve a bullseye gun. And, obviously on a D/A revolver, the cylinder must lock up before the hammer falls. The rest is just show and tell. My personal opinion, of course.

It seems that revolvers have an ethereal quality; how they work is difficult to distill, describe or explain, but they work nonetheless.

My affinity for revolvers, especially my SBH, is unsurprising, as I believe that form follows function and the best ability is dependability.