Cylinder lockup

[5of7]

Is it better in terms of accuracy that a cylinder lock up tightly, or would it be an advantage to have a few thousandths slop in the lockup.

I ask this because we can be pretty well assured that there is always some misalignment between the cylinder throats and the bore of the revolver and it seems that if the cylinder was free to turn slightly as the bullet leaves the throat and enters the forcing cone, that there would be less deformation to the bullet and hence better accuracy.

Has this ever been tested to find out one way or the other? One of the most accurate revolvers that I ever owned was little sloppy in the lockup. 8)

 

[Jimbo357mag]

I'm sure it would depend on the particular gun but generally for a Ruger I think a little loose is good because the parts are not as carefully fitted as they could be.

 

[GP100man]

There`s 2 schools of cyl lock up ,1 is tite as a rusted nut ,must be perfectly in time or accelerated wear on parts & spitting is inevetable & 2 a bit of loosness so it all can wiggle as it all lines up , much less maintenence & wear in the long run.

 

[Carry_Up]

Is it better in terms of accuracy that a cylinder lock up tightly, or would it be an advantage to have a few thousandths slop in the lockup.

I ask this because we can be pretty well assured that there is always some misalignment between the cylinder throats and the bore of the revolver and it seems that if the cylinder was free to turn slightly as the bullet leaves the throat and enters the forcing cone, that there would be less deformation to the bullet and hence better accuracy.

You are absolutely correct and will find tons of information on this very topic if you take some time to search out "lockup" and related terms. Unless a revolver is line bored (let's see, how many companies offer it???) it cannot mechanically align the chambers with the bore perfectly on every chamber. The majority will need some rotational and vertical play to compensate for normal machining tolerances. Installing oversized cylinder locking levers and oversized base pins remove all play and in most cases will adversely affect the accuracy due to bullet deformation. The forcing cone is the 3rd feature in this scenario which also allows the cylinder a bit of time to self-align as the bullet jumps forward from the throat.

 

[WOB]

If a revolver's chambers are line-bored while the cylinder is locked with the gun's mechanism, then a tight lock-up is desired. However a so-called tight lock up is only relative. There has to be enough clearance between the cylinder's locking notches and the cylinder bolt to allow reliable functioning. And there must be some clearance between the frame slot and the cylinder bolt for the same reason. In a well fitted custom revolver, there might be about .001" clearance in both places. This could theoretically sum to .002" total at the cylinder OD. The barrel's forcing cone can easily handle that much with very low bullet distortion. However, the gun must be kept clean and lubed to insure reliable operation.

WOB

 

[sixshooter_45]

Brownells sells a tool that checks bore to cylinder alignment to acceptable tolerances. I have one somewhere.

 

[Carry_Up]

If a revolver's chambers are line-bored while the cylinder is locked with the gun's mechanism, then a tight lock-up is desired.

Yes, that is what line boring does. It makes certain that the chambers will all line up with the bore.

However a so-called tight lock up is only relative.

I'm not sure what you are saying. There is nothing sneaky about the term "tight lockup". It means that the cylinder has no vertical or rotational play. The cylinder still rotates and carries up, it just doesn't move when it does carry up. There was a post here not long ago where a fine machinist went to unbelievable lengths to eliminate all play in the cylinder stop. I suggest you read the post. Strangely, there was never any question about whether the function of the gun would be compromised.

And there must be some clearance between the frame slot and the cylinder bolt for the same reason.

See the article referenced above which appeared here in the smithing section.

The barrel's forcing cone can easily handle that much with very low bullet distortion.

That's the whole point of line boring. Either you have normal play in a revolver and let the forcing cone "self align" the chambers, or you line bore the cylinder and forgo the forcing cone.

However, the gun must be kept clean and lubed to insure reliable operation.

I think we can all agree on that subject.

 

[flatgate]

Freedom Arms way vs. the Ruger Way.



flatgate

 

[cadillo]

Well today I fitted yet another oversized cylinder stop to one of my Old Model Blackhawks. I also fitted a Belt Mountain base pin, stretched the gas ring and fitted the cylinder with zero end shake, and then shimmed both the hammer and trigger. What a feel of quality such work gives to a single action. It may well be that doing so is somewhat detrimental to mechanical accuracy, but I'll never know, because I can't see well enough to shoot to the gun's potential either before or after, so smooth action and rock solid lockup are what matters to me provided things lineup within reason.

The largest pin gauge that will enter the muzzle is .351", and it will drop through to the recoil shield on five chambers, and a .350 pin will work in #6. No, it's not perfect, but I doubt that it's bad enough that I would ever notice any degradation of accuracy or propensity for fouling.

 

[contender]

The thread mentioned above about line boring & lock-up was posted by an excellent machinist who only works on his own projects. his forum name is; was1911
If you are truly interested in his work, look up his posts. He is a master in his understanding of how things SHOULD work. I was just surprised at how few folks truly appreciated his postings.
But, as noted, it's kinda like a Freedom Arms vs a Ruger. Just look at the expense of a FA vs a Ruger. You have to pay more to get a tighter gun.

 

[cadillo]

................But, as noted, it's kinda like a Freedom Arms vs a Ruger. Just look at the expense of a FA vs a Ruger. You have to pay more to get a tighter gun.

Well as someone once said, "There are no absolutes." I too have a Freedom Arms gun; a Model 97 in .44 Special. It locks up no more nor less tight than my latest Ruger tune up gun mentioned above. The one thing that the Model 97 has that my Ruger doesn't is measurable bore choke just aft of the front sight, probably a result of a little overly judicious application of heat during the soldering of the front sight mount. It IS tighter there alright.

Also, the chambers of the FA actually gauge a little looser than those of my Ruger Flat Top .44 Special. The throats gauge fine, but the chambers are on the loose side, at least compared to my Ruger .44.

Freedom Arms guns are nice, but they do cost several times more than my Rugers, and they are not perfect, and if I had to sell one in a pinch. The FA would go before any of my Old Model Blackhawks, and also before any of my New Models that have been tuned.

Did I mention that for the price of a Model 97 FA, I can buy and tune to my liking three (3) Blackhawks?

Sort of reminds me of something once said by one of my favorite authors:


“There are as many answers to that one as there are reasons men hunt, fight, skydive, gamble or take up with redheaded ladies”

Peter Hathaway Capstick

 

[contender]

Well, I own only one FA, and MANY Rugers. The fit, finish, lockup, etc of the FA is tighter than any of my Rugers. But, both shoot pretty darned good. However, overall the FA is put together with a lot more detail to how well it will shoot & lock up etc. And, I've had the pleasure of visiting the FA plant. The folks there spend a lot more time putting together a handgun than the mass produced Rugers. I'm not knocking Rugers, Lord knows I love mine. And I can fully agree that anybody can make a mistake or a bad gun etc.
But in general, I feel the FA's are put together with more attention to tolerances than Rugers. But to get that kind of workmanship, it costs more.
I don't doubt your FA is looser than a Ruger. And I can agree that for the price of one FA can equal 2-3 good OM Rugers. But I think the OP & that discussion is a general question about Rugers & other guns in regards to lockup.

 

[flatgate]

I worked at Freedom Arms for around 3 years until an "off the job" accident ended my job there. I've been shooting/collecting Rugers for many more years but there is NOT any comparison between the two guns.
Compare a '63 Corvette with the latest version. The more modern version wins every time

JMHO,

flatgate

 

[cadillo]

I worked at Freedom Arms for around 3 years until an "off the job" accident ended my job there. I've been shooting/collecting Rugers for many more years but there is NOT any comparison between the two guns.
Compare a '63 Corvette with the latest version. The more modern version wins every time

JMHO,

flatgate

It appears that you really love Freedom Arms guns, and prefer them to Rugers. That's nice! I own both and actually prefer the Ruger Old Model to all others including Freedom Arms and Colt, but that's just the way I'm wired. Your statement about the Corvettes is so broad as to be simply not true.

If I had the latest version of the Corvette, I could check the oil; change a tire; replace hoses, belts, air filters, etc.; but if it ever developed a miss, like most folks, I would have to take it to the dealership and pay $100.00 plus per hour to have a 'Technician" do a diagnostics test on it.

If I had a '63 Vette, I, could tune it, rebuild the carb, pull the engine, tear it down, take the crank, block, connecting rods and heads to the machine shop for some TLC, and then reassemble the whole thing and make it run like new again, all without a computerized machine that costs thousands of dollars, and without having to go to some GM trade school to learn how to "Diagnose it". Plus the '63 Vette will go as fast as any sane man needs to drive anyhow. For me, that makes the '63 the clear winner.

"The more complicated they make the plumbing...the easier it is to stop-up the drains!"

 

[Jim Puke]

I worked at Freedom Arms for around 3 years until an "off the job" accident ended my job there. I've been shooting/collecting Rugers for many more years but there is NOT any comparison between the two guns.
Compare a '63 Corvette with the latest version. The more modern version wins every time

JMHO,

flatgate

Bingo!