Open top that over rotates, What is the problem?

[chunik bair]

Hi

Am new to this forum and have a question. I have a Open top in 38 sp that over rotates cylinder if I cock hammer too fast, seems to work o.k if I cock slowly. Now have read Larson Pettifrogger's articles on tunning open tops, which were real helpful. and have had local gunsmith fit Plunger type hand spring which made the gun a lot smoother but still over rotates, Do I need stronger hand spring or is something else the problem?
Have founds lots of information on this forum and would appreicate any help.
N.B Ilive in New Zealand and Have 2 open tops in 38 sp,1 Dragoon, 1 1860 C&B and 1 1858 Remmington

THanks

[Pettifogger]

A couple of things to check before going to far.  First, what kind of bolt/trigger spring does it have?  Is it still the stock or an aftermarket leaf or has a wire bolt spring been installed?  If it has a wire, replace it with the original leaf and see how it works.  If it is the stock spring, the next thing to check is the bolt timing.  Cock the gun very slowing and watch the bolt.  Where is it dropping?  If it is dropping to late in the cycle it can cause over rotation.  Sounds like from your description that it was over rotating before the hand spring was converted to coil so that is not likely the problem.

[Raven]

I second Pettifoggers advice!

Raven

[rifle]

Usually an out of time bolt doesn't wear and get late in the cycle. It would get early and then at least be there on the cylinder to catch the notch. If someone worked on it and timed it wrong or  didn't  time it then it could be late in the cycle.
I'd check it's trigger bolt spring first. Check for invisible fractures in a flat spring or weakness to  a wire piano wiire spring or even a loose or stripped threads trigger bolt spring screw.
Worn cylinder notches,a bolt with the leading edge that stops the cylinder being worn or not centered, bolt loose in the frame window and/or loose on it's screw are some things to look at/for.
You may have to fresh up the leading edge of the bolt  and get the worn or overly rounded edge back to being a little sharper.
Your hands spring initially may have been weak and the new coil spring may also be weak. Simply half cock the gun amd turn the cylinder and listen to the hand click as it leaves one ratchet tooth and hits below it. The clicks shouldn't be weak sounding. If the bolt is prime and your cylinder turns and free wheels very easily like it's been really polished in the cylinder hole and on the arbor and gets too fast because of a weak hand spring that could be a problem.

[Raven]

Good advice Rifle.

In my experience these revolvers are not timed for SASS competition shooting.
When cycled at the speeds competition shooters use a NEW gun with standard timing will carry past.
The bolt must be timed for the style of shooting that the owner practices.

Raven

[Abilene]

I was told by Loose Cannon Lou, who was taught by the late Bob Taylor, that the ideal timing for OT's and conversions can be checked visually by looking at the top of the gun while working the action.  While cocking the gun very slowly, the bolt should pop up when the leading edge of the bolt slot is perfectly lined up with the left edge of the hammer cutout in the frame.  See the attached picture.  The picture is a conversion but the same principal holds for the '72 Opentop.  Of my four '51 Richards-Masons, three were timed fine from the factory and would lock up every time with fast two-handed shooting.  One of them would over-rotate about once per match.  Lou advanced the timing just slightly on that one and it has been fine since then.  The timing will slowly advance (the bolt pops up sooner) over time as the bolt leg wears, but that is fine.  If it gets too advanced, the bolt will start popping up before the lead-in ramp to the bolt slot and you will start to see a line on the cylinder before the ramp.  On my guns, the timing has advanced over time so that the bolt pops up just very slightly before the cylinder reaches the point shown in the picture.  If the bolt on your gun pops up after this point, you may need to have the timing advanced.  Fortunately, advancing the timing is much easier than retarding it 

[Fox Creek Kid]

Rifle ol' buddy, it's good to see you back!! Where ya been? 

[Pettifogger]

"Usually an out of time bolt doesn't wear and get late in the cycle. It would get early and then at least be there on the cylinder to catch the notch. If someone worked on it and timed it wrong or  didn't  time it then it could be late in the cycle."  True, but he didn't say if this was a used gun that has just started over rotating or a new one.  I have had several new ones that the bolt dropped way to late.  Basically, easy to check as you don't have to take the gun apart and gives us a starting point for trying to figure out what is wrong.

[chunik bair]

Thanks Guys

i brought gun new 2-3 years ago and have put 1000-2000 rds thru it, it only started over rotating about 6 months ago which is why I put plunger hand spring in.
it is still standard bolt /trigger spring. If I put it on half cock and turned cylinder slowly and hand sounds like it is strong enough.
If I cock it fast and it over rotates, I can turn cylinder back slightly and it locks up, and looking at bolt notches on the cylinder it appears almost like the bolt isn't fitting in right, altho if cocked slowly it never over rotates.
Also a light ring has appeared on cylinder from the bolt touching and appears to be more pronounced at back? side of notch,ie score mark brightest as cylinder is rotating away from firing position, ( Hope I made that understandable!!!) also slight wear mark on foward end of lead ramp, just before notch - not sure if making that clear as just trying to describe as i see it.
Have read and checked out what abilene said about cocking slowly and lining up notch and both my OT are the same, ( one doesn't over rotate, least not yet!)
From reading what you guys have written it most prob is a bolt or timing problem.
How do I check if bolt is dropping to early or to late?
The problem here in New Zealand is most gunsmiths don't specalise in pistols as they are not that common so I need to narrow problems down to get it fixed.
I really appreciate you help and have found you guys real informative. Also how long should these guns last as I also have Uberti SAA clone that is ten years old, had heaps of rounds thru it and never misses a beat!!

Thanks again

[Fox Creek Kid]

For fast & furious two handed (non-historically correct) style shooting you will need to have someone advance the bolt. It is not a job for any amateur. If you absolutely must shoot this way and no know no 'smith thereabouts then buy the Kunhausen book on Colt SAA's as he explains how the bolt works and you can attempt it. There are no shortcuts. Practice on a "beater" gun if you must.

Better yet, shoot them as they were meant, one handed & with real BP like a man. 

[chunik bair]

Thanks for that,
altho i don't shoot real fast! it still doesn't solve the problem really, just would like gun to run well, I might have to practise shooting one handed just in case. Also have a couple of C&B for black powder!
The dragoon is a bit heavy for one handed though!

Thanks

[Goody]

I would say the first order of business is to get a new Wolff flat bolt/trigger spring and give that a try. You will venture less than $25 for both pistols, and it just might fix the one and stave off the breakage of the second. I have broken these before and it is not usually a snapped off leg. If you look closely at them as was suggested earlier you may see a crack developing where the bolt spring portion begins, just ahaead of the screw.

[Nine Toe Jim]

I had two SAA that I put Wolf wire springs in and they worked well. I passed the pistols on to my son in law and obtained an 1872 open top and an 1860 Richards_Mason. I put the wire Wolf springs in them and had over rotation quite frequently. I tried to bend the springs to adjust then but no luck. I put the original springs back in and have never had a problem since. Both pistols are in 45 S&W.

NTJ

[Niederlander]

I've tried the wire springs in both an original SAA and in replica SA's and C & B's.  I've since gone back to Wolff flat springs.  They have a much better "feel".

[chunik bair]

 
Thanks guys,

have ordered new flat springs but won't get them for a few days, will let you know how I get on

[rifle]

"Number one" step I use to tune a single action for the rigors of Cowboy shooting is to make a "bolt head bolster" part to add to the gun. The bolt head bolster part stabilizes the bolt head supported by the thin edges of the frame window and by it's loose fit on it's screw....so the bolt head can't retract into the frame under the force of the cylinder turning fast and cause over rotation.
The bolt head  bolster can be used to help in aligning the chambers to the bore also.
The bolt head bolster can be made by hand but a mill used to keeps it's sides perpendicular to it's top and bottom is a good thing.
Describe the part? OK.
Looking into the gun with the trigger guard off and the gun upside down.......The part fits in the space in front of the bolt screw,next to the bolt head with one end fit to the curvature of the millout in the frame and the other end, having a groove in it, is fit to the bolts screw with a tab of steel above and below the screw. The other side opposite the side that is a real close fit to the side of the bolt head is against the frame wall . The part is made of steel but brass or any other metal can be used.
The part sits under the trigger leg of the trigger/bolt spring and if fit right can't move anywhere and supports the bolt head against the force of the turning cylinder. The bolt head bolster keeps the bolt head from canting under the force and letting the cylinders notch edge force the bolt head into the frame enough to let the cylinder over rotate.
This part is of great significance to a good tune up of a single action revolver for Cowboy Shooting. Why it isn't mentioned more I can only guess but......I'm hoping people will see the significance of this added part to a single action revolver.
Maybe someone can make one of the parts and show pics of it. Someone good at tune ups and gunsmithing and writting and taking pics...like Pettifogger......
I've made plenty of the "Bolt head bolsters" as part of a tune up for cap&ballers and cartridge single actions so I can answer questions about making one and fitting it in the gun.
Even a gun with a bolt head snug in the frame window and snug on it''s screw will be able to move under the force of the spinning cylinder and act against the bolt spring and retract some....since the frame window is thin and there is always some loose to the fit of the bolts screw in the bolts screw hole. A stiffer spring many times cures the symptom and not the cause.
One other movement of the bolt takes place at the other end where the legs are against the  frame and the hammer. This is not often mentioned. Simply put the legs of the bolt are springs and emitt force against the frame and hammer. The leg on the hammer emitting force against the hammer can,at the time it is almost to the top of the cam but the hammers cam isn't high enough for the bolt leg to get atop it, move itself up on it's own spring power and get ahead of the cycle snapping up onto the hammers cam. That happens because of a bevel to the top edge of the cam or wear to the top cam edge or a cannting of the hammer,thus the cam,  due to too much force the bolt legs are emitting between the hammer and the frame when the bolt leg is on the cam.
"Canting" of the parts in just the right way to make the force of the bolt legs springiness move the bolt leg under it's own powder up on the cam before the cam is actually low enough in it's cycle. This moves the opposite side of the bolt, thus the bolts head, down or into the frame just as the gun fires. This means the gun fires while it is actually not locked into battery and may actually be slightly over rotated and mis-aligning the chamber to the bore. An accuracy problem can result....a problem that is difficult to diagnos. It can be seen if the gun is worked in it's cycle very slowly with the cylinder off the gun and the person has a good eye for "eye-ballin".
The adjustment has to be made to the cams top edge and to the spring force of the bolt legs against the hammer and frame and the fit of the bolt on it's screw and the fit of the hammer in it's recess and on it's screw and to the stabilization of the bolts head in the frame window with a "bolt head bolster" part or oor a better fitting bolt screw or whichever of these solves the problem. It can be all the above or just some of the above. A stiffer bolt spring usually doesn't cure this self movement of the bolt leg snapping prematurely up onto the hammers cam. This problem can help the cylinder over rotate.
Anywhooooo........I post my opinions of things I post about independant of what someone else may post. I don't do it to contradict anyone but just to give my opinion. Maybe to clarify. That's how we learn from each other and help each other. I learn things from you Cowboys all the time. I even learned a coupla tricks from the "Illustrious Fox Creek Kid".
I've had computer problems Fox Creek. I gots me anuther now. Glad to see you are still kicking.

[PJ Hardtack]

One of my '51 Navy's (a Colt BP product from the '70s) would over-rotate on a 'speed cock'. The problem turned out to be a too-thick locking bolt. Thinning it down a bit solved the problem.

[Fox Creek Kid]

Rifle, I was reading Fox News so I missed your last post. Could you retype it, please! 

Rifle, I am almost positive ASM did this years ago on their SAA's. I had one once that I bought in early 2000 that had this bolt "block" off to the side to do just what you said. Pettifogger or Coffinmaker have surely seen more ASM SAA's than I have so maybe they'll chime in.

[Coffinmaker]

Every ASM Conversion I've ever worked on (quite a few) have had a little "block" or "spacer" fitted to the lock works to prevent the bolt from moving from side to side.  The bolts were a little small for the window.
The blocks were machined to be retained by the bolt spring screw and filled in the space from the side of the mortice to the side of the bolt.  It works.  If however, the bolt fits the window, it isn't necessary.
Most examples of "throw by" are a result of the bolt not fitting the cylinder slots correctly and or a weak trigger/bolt spring and or late timing.  The bolt must fit all cylinder slots. it should be timed to rise into the lead and the spring needs to be nice and crisp.  I don't like wire trigger/bolt springs (just a personal "feel" thing).

Coffinmaker

[rifle]

yer right Fox Creek and Coffinmaker about the ASM having those bolt bolsters/blocks. Not all had them though (I have one that came without it ....bolt bolster/block). I thunk maybe they used them for chamber to bore alignment. That purpose was when I first got the idea. I wish I had known about the ASM earlier to save me the trouble of ruining some brain cells thunkin it up. I only gots two or three left.   Sniffin that blackpowder smoke may be doing that. Of course that smoke is what is keepin me alive I thunk, See....that makes no sense to anyone but me and my coupla brain cells. If I keep all three of my brain cells I can name them Larry,Curly and Moe.
I don't think ASM used the groove to straddle the bolt screw though and that is a nice way to keep them(bolt bolster/block) right in place. You have to make it fit in that recess kinda tight like it sorta snaps in place.
I use that bolt bolster in conjunction with a flat shim of copper or brass or aluminum(between bolt and frame wall) to set the left/right to align chambers to bores. Alignment really helps the cap&ballers.
Anyway that bolt bolster/block does help stabilize the bollts to take the stress of fast cycling like in the Cowboy Competition, I don't see it mentioned much at all and that's strange because it's such a neat part and does several things that are posituve.
Anywhoooo.......I'd like to see one of those articles/tutorials/how to's with pics and all about the part so it can get more widely known/used by the Hombres that do the ultra shootin in Cowgoy Competition........used by the average cap&baller plinkers too. The "plinkers" are people that count for sumpthin too ya know.
I'd have to respectifully disagree with Coffin Maker when he says if the bolt fits the window the bolt bolster/block isn't needed. I tried to explain in my first post up there why /how a bolt can move even when it fits the frame window. The movement is caused by bolts that are loose on the screw and the thin border around a frame window and how far the cylinder is from the frame and how tall the bolt head has to be ect.ect..
All one has to do is set the bolt in the frame all by itself and notice how the bolt can move/cant even when it's snug in the frame window. The bolt has to move in the frame window and on it's screw and to move it needs space between it and the frame and to the hole the bolt screw goes thru so there is always some movement of the bolt that can let the bolt cant some from the cylinder hitting it. I believe every single action can benifit from having a bolt bolster/block. That's my opinion and it's stuck to one of my brain cells and I can't shake it loose and certainly don't want to shoot it loose.
I know that all that has to be brought  up is the evidence that there are millions of guns working well out there without the bolt block but......if used a lot for CASS shootin they all can be helped by the bolt bolster/block to be more reliable and lengrhen the longevity of the guns by helping to save the cylinder notch on that side that takes a real beating.
Coffinmaker mentioned fixing a lot of ASM conversions (are you a pro gunsmith Coffinmaker?)and I was wondering what the most prominent problem would be with those guns? I know the triggers on both mine came out of the box with too much negative angle to the tumbler notch(full cock notch on the hammer) and the triggers were way too light and one without the bolt block/bolster would do the "throw-by".(is that the right term for over rotation?) I like the guns now that I gots the triggers right and the throw-by stopped. Fox Creek didn't like how they gummed up from blackpowder fouling.