Shot my R-M 51's, Do They Need Work?

[Dalion]

Got my second R-M Navy 51, after the 40 day waiting period, and shot them.  I am amazed how accurate these pistol are and how much fun it is to shoot them Gunfighter style.  But I had a couple of misfires that at first I attributed to a week hammer or maybe a burr.  But later I found that if I cocked the hammers a little too vigorously the cylinder would over rotate and the hammer would not come down on the primer.  Is this common with these pistols?  Or do they need to be timed?  When I shoot them one handed there is no problem, but I guess I got a little excited when I shot them two handed.  Any advise you can lend would be greatly appreciated.

[1860]

Well, they need something done, could be the bolt dropping in a little late(timing) but it is more likely the shape of the bolt head itself since they work OK one handed(slower/softer cocking).

With the hammer cocked, is there any side play in the cylinder when you rotate it back and forth?
  If there is none then it is possible that the bolt head does not fully engage the knotch in the cylinder (it's too fat) and when you cock it fast it skips out of the knotch and over rotates.
  Or the hand it a tad too long (don't file it yet) and it pushes the cylinder past the bolt.  (Not likly or you would probably get a lockup when first cocking, cylinder tries to rotate befor the bolt is withdrawn).

You can also check the above with the cylinder and bolt out of the gun, visually make sure the bolt fits complety in the knotch.  While you have it out, look at the top of the bolt, it should be slightly angled, the top of the right side should be a little higher than the left as it sits in the gun.  The right side is what stops the cylinder rotation and it's higher so that it gets a better "bite" in the knotch-also so it better rides down the little bevel cut in the cylinder knotches.  The right side of the bolt (not the top) should be perfectly flat, sometimes they take a little off to make it fit the knotches and if they did it on the right then it will be slightly angled and more liable to slip out of the knotch, don't file anything yet but if you have to, take it off the left side and only near the top(just the bolt head).

Of course, this could also be a weak trigger/bolt spring. 

Do both of your guns do this? 

These guns should run as good as your average SAA but over-rotation is not uncommon.  I mainly shoot a pair of those ASM Richards Conversions that had issues but are now fine, same with my Uberti C&B Colts but my Cimaron 72 wanted to over rotate when new.  Some minor polishing of the bolt took care of it and I can slam it around with no troubles.  That said, I shoot onehanded and don't often run them real hard.  Grace befor speed!!

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[Ottawa Creek Bill]

Just keep in that these are copies of 19th century black powder firearms for use with black powder, and not made to shoot CAS matches like you see in SASS 10,000 to 20,000 rounds a year unlike the Ruger which is not a copy of anything but is a modern hand gun and made to take the abuse of CAS. Smooth out the burrs and sharp edges and you'll probably be just fine.

OCB

[1860]

Ottawa,

That is why I asked if they are both doing it, if so then he may just be running them a little too hard as I doubt both will be fitted incorrectloy in the exact same way.  After all, they are just mechanical machines and any machine can be over stressed and made to fail.

Seth,

Just for my general knowledge, can you explain how/why the hand and spring can stop over rotation?

The way I see it, the hand spring ensures that the hand drops under the knotch and stays there so the hand can rotate the cylinder as the hammer is cocked. Once the cylinder indexes to where the bolt drops back onto and then into the cylinder knotch & then the trigger falls to full cock, the hands job is over.  If the spring is too weak then the hand may slip off the knotch and fail to rotate the cylinder completely.  It's the inirtia generated by the cylinder rotation that acts to have it "blow" past the bolt head as evidenced by the fact that his guns work fine when cycled slowly by fail when run hard.  At this point the hand should no longer be pushing the cylinder rotation-(Unless it's a tad to long)-and it has no power to stop over rotation because if will just slip down the beveled groove on the rear of the cylinder as if over rotates.  It would take a mighty strong hand spring to deter the cylinder rotation by applying the friction of the hand tip on the rear of the cylinder.  I can see what you are getting at but I think it may just be masking the real issue and by appling that much preasure between the hand tip and the rear of the cylinder, it may cause premature wear to the tip of the hand.  Just my .02


Dalion,

Don't file anything yet and don't bend that hand spring, leaf springs (even the newer semi-rounded ones) do not like to be bent and do not stay long where you bend them, especially the cheap hand springs commonly used on these guns.  There is a speciall tool called a 3-ball-bender that is used, Orthodontists use them to bend the thicker spring wire on brases, it puts a slight bend in the middle of the spring by using two points of contact on one side of the spring and one point that is inbetween them on the other.  To check the hand spring tension,remove the cylinder and with the hammer down, push on the hand tip, there should be tension and no "flop" in the hand.  Repeat this at half cock and full cock, at full cock there may be a little flop since the hand sticks out much further than it normally would with the cylinder in place.  Even a little @ half cock would be OK, a weak hand spring will cause the cylinder not to rotate, just spinning the cylinder @ half cock and getting a resounding click-click-click is a good indication of a healthy spring.

Let us know how you are doing..

60

[Dalion]

60'

My first one, which has been shot the most, does over rotate much less than the new one.  I really have to purposely jack the hammer back on the first one to get it to over rotate.  The new one is little easier to get to over rotate.  The hand spring tension on both is good.  Neither of them has much to any wobble. When I rotate the cylinder there is a good strong click to it. 

The bolt notch on the cylinder on the new one already has some blue worn of the right side edge of the notch.  Whereas the first Navy, which has been shot a lot, does not have any blue wear on the cylinder notches at all.

[Fox Creek Kid]

Firstly, if you're using piano wire bolt springs then throw them away. They can contribute to over rotation. As a few have pointed out, these guns were meant to be shot one handed & cocked authoritatively, but not "racked" with the other hand's thumb like a machine gun bolt. You can also bend the arm of the flat bolt spring up a tad to cause the bolt to engage with more "oomph".

Most of the serious CAS "gamers" will have a good CAS gunsmith time their guns so the bolt rises a little early to help. I don't recommend this unless you are Evil Roy's protegé. 

[Galloway]

I have an open top that over rotated when cocked hard at first. It turned out the bolt and trigger screws were loose. I tightend them down and its run fine ever since. Good luck

[1860]

Dalion,

When you say it has wear on the right side, is that with a particular knotch viewed while rotated on the top of the gun.  or another way to tell, is the wear on the side of the knotch that is beveled?

Either way, you need to remove the bolt and check how it fits in the cylinder knotches as I described above.  I've seen quite a few that are a little too fat and don't seat all the way to the bottom of the knotch.  Good enough to hold it under light force but it can skip out under preasure.  I think they do this so there is no wobble at full cock, most guys checking out new guns like it when they have no play but there should be just a very very little.  While you have it out, take a good look at it under a strong glass, make sure it has no burrs on the edges of the bolt and the top of it should be very smooth and shiny.  Either could cause your over rotation and/or wear to the blueing.

Something else to check or be aware of:  Before you remove the bolt, take the grip frame and trigger guard off and check the play while looking at the bolt from the bottom of the gun.  Sometimes the slight play you feel/see is the bolt assembly moving back and forth in the cutout where it goes through the frame-you may see the entire bolt moving back and forth.  If this is the case then the bolt head may indeed be too thick for the knotches and you just felt the bolt assembly moving.  Another reason to take it apart and check it.  I would not take any metal off yet!! Lets see where we are first because these things are hard to diagnose by remote control so to speak..LOL

Any polishing done to these parts should be done with stones, they come in different grits and do a fine job of polishing without removing too much metal.  You can also use crocus cloth-as fine as you can get-wrap it around something flat and take your time.
http://www.onlineindustrialsupply.com/crclsh.html

There are a few other things that can be the cause and also a rather quick fix that is not always the best way to go in the long run-I like to fix em right.  But if you are interested, the trigger/bolt spring may be a little weak, I had one made out of wire that allowed it to over rotate easily.  You can order another and give it a try.  If that is not it then cut off the leg of the spring for the trigger and double up on the springs, put the full spring in first and then the one that only has the bolt spring left.  Try it befor you install the trigger guard because there may not be enough room for both springs when you cycle the gun. Cycle the action and watch the springs if they stick out past the bottom edge of the frame you will have trouble once the trigger guard is installed.  This may stop the over rotation but it can also cause premature wear on the hammer cam and the leg of the bolt that follows the cam.  Might even accelerate your blueing loss and wear on the cylinder depending on other timing factors.

That's enough for now..

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