ROA misfires


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ottsm
October 5, 2012, 06:41 PM
I have 3 ROA's. One SS, One Blued, both with target sights. Awhile back I ran into a SS high polished fixed sight version to make up my 3rd one. I took both SS versions out today at the range. I had never shot the fixed sight version yet. I've always used #10 Remington caps and they have always worked reliably.

Shot the target sight version first for awhile, everything great as usual.

Next I loaded the Fixed sight version, lined up the sights, pulled the trigger, misfire, backed up the cylinder and tried again, fired that time. Next time was also a misfire. Tried the other shots, some shot and some didn't. If I backed up and tried again they would eventually fire. Next round I made sure to get the caps down as far as I could. This seem to help some but still had misfires.

Not sure what the problem is, perhaps the clearance between the nipple and the hammer must be too great. I measured the nipples with a caliper and compared them to my target sight ROA, seemed to be the same overall length. The diameter might be a tad larger, the #10's seem to fit a little snug in comparison. Could this be the issue, perhaps it needs #11's?

Doesn't look like the unit was dry fired a lot, hammer seemed to be in good shape. One thing I do notice is that my target sight ROA has SS nipples and the Fixed Sight polished version has steel nipples (both had the Ruger hex head style nipples so they don't appear to be after market).

Anyone have a similar issue?

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Jaymo
October 5, 2012, 07:40 PM
Maybe the previous owner replaced the factory hammer spring with a lighter weight, aftermarket spring.
I'd try swapping hammer springs with one of your other ROAs, and see if the problem follows the spring. It's a quick way to confirm or eliminate light strikes as the culprit.
My 1976 ROA likes CCI 11s, which is good, because I can't find Remington 10s locally, anymore..
I save my Remington 10s for my Italian BP revolvers.

arcticap
October 5, 2012, 08:00 PM
The ROA was designed to have tight enough tolerances to allow dry firing without damaging the nipples. So it's conceivable that occasionally the tolerances will be too loose for it to function properly and as intended.
There's options for dealing with it. If the mainspring, better nipples or different caps don't help then perhaps if there's a part of the hammer that's engaging the frame too early, a small adjustment can be made to allow closer contact of the hammer & nipple. Or similarly, a small part of the frame could be interfering with the hammer fall which could be adjusted to a small degree.
If there's a choice, it's better to try to adjust or replace the part[s] that are easier to replace.
CCI caps are said to have the thickest amount of primer material inside of their cups, and they may have thicker metal too. Or try their magum caps which are also sold as #11 Winchester Magnums at many Walmart stores. So maybe that little extra amount could fill in the .00xx gap that's leading to poor ignition. Or try another set of nipples like the Slix-shot or Treso.

http://longhunt.com/storelh/index.php?route=product/product&product_id=267

J-Bar
October 5, 2012, 08:58 PM
I own a pair of ROA stainless fixed sight 7.5s that came with Ruger factory nipples and neither gun has ever misfired.

Then I bought a pair of 5.5s that had Ruger factory nipples and they misfired frequently. I changed to Treso nipples on this pair and have not had a misfire since.

So, some Ruger factory nipples are better than others.

Before you start messing around with springs and grinding critical tolerances, swap out the nipples. Please.

ottsm
October 5, 2012, 09:14 PM
Thanks guys. I'll swap the nipples with my other ROA for sure and see what that does. Believe I bought some spare nipples with my first ROA, now if I could just remember where I put them.

Guess Ruger must have changed from SS to steel at some point?

Pancho
October 5, 2012, 09:26 PM
You could try seating the caps with a wooden dowel to make sure they are in close contact with the nipple face. Thumb seating is the ideal situation but not always the case.
If the gun fires reliably after seating with the dowel I would suspect the nipples not being the correct size for your caps. Switching your nipples with the reliable gun would prove the same thing but is a little more complex.

arcticap
October 5, 2012, 09:44 PM
Another idea would be to shim the nipples in order to raise them. It's easy to make your own shims or they can be bought from an outfit like Mcmaster Carr.
Hellgate posted about how to make nipple shims:



-He needs to shim that one nipple up a few thou. Not just back it out. It is easy to shim nipples. Take soft fine steel or bronze wire and coil it around a nail or screw shank about 10 times to make a spiral the diameter of the threaded shank on the nipples. Then with wire cutters snip them off and you end up with a pile of what look like lock washers. I then I take a small hammer and flatten them on the vise pounding surface or an anvil to the desired thickness. They resemble small open ended lock washers. Slip one onto the shank of the low nipple and screw it in. I use anti-seize lube or heavy lithium grease on the threads so I can get the nipples back out. If the nipple is too high, pound the shim flatter or find some finer wire. If it still isn't tall enough, use two shims or get a thicker piece of wire to start over with. I've done this on several guns and have had no problems with it. If you have too high of a nipple then the hammer face gets battered and may not fire the other nipples or it will get burrs on it that may lift spent caps off the nipples and drop them into the action.

http://www.thehighroad.org/showthread.php?t=440611&page=2&highlight=shim

Shims:

http://www.mcmaster.com/#shims/=jlfy1v

Jim, West PA
October 5, 2012, 10:56 PM
The correct size 'shims' can be purchased at a hobbie shop that sells RC airplanes and cars.


Hey Steve, what are the cross holes for in the Slix-Shots ?

Patocazador
October 6, 2012, 04:29 AM
You could try seating the caps with a wooden dowel to make sure they are in close contact with the nipple face. Thumb seating is the ideal situation but not always the case.
If the gun fires reliably after seating with the dowel I would suspect the nipples not being the correct size for your caps. Switching your nipples with the reliable gun would prove the same thing but is a little more complex.
This is probably the problem since it fires the second time around. The 1st shot seats the cap, the second ignites it. Use a bigger cap like Pancho suggested.

AJumbo
October 6, 2012, 02:02 PM
I ran into this problem with CC Magnum #11s, versus standard #10s. The Magnums were just a little longer and that created enough extra grip on the nipple keep the cap from seating fully. I went back to regular #10s and there was no more issue.

It would be great if all the manufacturers #11s were the same size, but that just isn't the case. Since there are bound to be tolerance variations between runs of nipples as well, you just have to find a cap that works and stick with it. My ROA like CCI 10s and RWS 11s.

arcticap
October 6, 2012, 03:14 PM
Hey Steve, what are the cross holes for in the Slix-Shots ?

My guess is that the hole is to redirect the back flash out toward the cap's sidewall so that the cap remnant won't be as likely to get blasted backward off the nipple. :rolleyes:

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