RG45-70 fail to fire/light hammer strike/no strike

Rossi's latest and past big game rifle based on the 336 frame!
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by Centaur 1 »

Arroyoshark wrote: I have followed a lot of comments and the gun smithing work on the Rio Grande by Tuco Ramerez as well as Centaur. Centaur has not posted here for over a year, so I do not know the final outcome of his work.
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After a lot of frustration I put my Rio Grande in the safe, where it sat for the last couple of years while I completed another project.
Arroyoshark wrote: Third, Hammer drop:

What was disturbing, back out at the range, was that I did continue to experience the hammer stopping several times at near the half cock position, causing a failure to fire.

I reviewed the modifications done by Centaur in this thread.

For reference,
http://www.rossi-rifleman.com/viewtopic ... 6&start=40

I would like to raise a red flag to the modifications he made to the hammer.

If you remove the cross bolt safety from the frame and peer into the hole for the safety, then operate the hammer, you will find that the part of the hammer that Centaur whittled away does not actually touch the receiver frame. That is the part that engages the interference portion of the cross-bolt safety. If you whittle much material from the hammer, it will compromise the hammer blocking safety. Just a heads up here ! I would not do this. I think Centaur was close to the problem, but he was going after the wrong part as I discovered.
Looking Back I should've included a warning to keep an eye on the space between the hammer and firing pin with the safety engaged. In my defense, even though I removed material from the hammer, the cross bolt safety still prevents the hammer from coming anywhere near the firing pin. When the hammer is compared with a 336 hammer, the Rossi has more metal where it meets the cross bolt safety. This extra material prevents the hammer from driving the firing pin all the way forward when the safety is off.
Arroyoshark wrote: Fourth, Cross-Bolt Safety:

This little part turned out to be a smoking gun !

Out at the range, I noticed that when the hammer was captured at the half cock position, when the trigger was pulled, it was due to some very minor interference with the safety. Seems the safety moved back and forth on my Rio Grande way too easily. The recoil, plus cycling the lever often caused the safety to move to right a slight amount, enough to block the hammer. If I pushed the safety to left before each shot, the round would go off - not a solution in my mind.

To test this I removed the stock in order to remove the tension screw, spring and ball detent for the safety, so I could remove the safety to the right. The first thing I noticed was that the tension screw was backed out a fair amount. This apparently significantly reduced the tension on the ball detent allowing some free movement of the cross bolt safety. I also discovered that tightening the tension screw down tight, resulted in making the cross bolt safety impossible to push back and forth. It was locked in place.

I completely removed the tension screw and ball detent, and the safety. Once more I tried some rounds. What I discovered was no hammer drop failures, no rounds that did not go off. In reviewing the symptoms that several other RG owners experienced, the failure of the hammer to fully drop when trigger pulled, and the fact it fell to nearly half cock position, supports in my mind, that either the cross-bolt safety is not manufactured to correct tolerances, and/or the tension screw backs out under extended firings, resulting in not enough pressure in the ball detent to hold the safety in the fire position.

If you experience hammer falling problems when pulling the trigger, check for interference with the cross bolt safety. Pull the butt stock off and examine whether the tension screw has backed out too far.
After a couple of years of messing around with this rifle, I never was able to make it fire reliably. Every time I made a change it would get better, but it always failed to fire a few times whenever I took it to the range.

Thanks to this thread I decided to take another look at my RG. The first thing I did was inspect the cross bolt safety. Not only was it loose, but it was able to rotate. Every time it rotated, the cutout that allows clearance for the hammer would block the hammer from striking the firing pin. I removed the stock and the detent screw was loose. After cleaning all the parts, I reassembled the safety and now it's working properly. Hopefully it'll fire every time when I take it to the range later this week.

The saga continues. :?
"We have federal regulations and state laws that prohibit hunting ducks with more than three rounds. And yet it's legal to hunt humans with 15-round, 30-round, even 150-round magazines." Senator Dianne Feinstein (D-California)
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by akuser47 »

Good to hear and good to see you +guns keep us posted +corn
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by Ranch Dog »

Welcome back! Great follow up, thanks!
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by Centaur 1 »

Well I finally got out a few days ago and put a couple of boxes of ammo through my rifle. For the first time ever it fired every single time I pulled the trigger, yay. As a retired tool and die maker and gunsmithing hobbyist, this rifle tested my patience. I knew that the work I did to the rifle was done properly, but the more I did the number of misfires slowly increased. Turned out to be the set screw holding the safety ball detent was loosening up. Without sufficient spring tension, the crossbolt safety would rotate slightly when the rifle recoiled. On the next shot the hammer would contact the safety just enough to soften the impact of the firing pin on the primer. The fallen hammer would rotate the safety back where it belonged, and the next time I pulled the trigger the rifle fired. I just tightened the set screw so it locked up the safety in the off position to test if it would solve the problem. Reading this post is what made me look at that screw, so thank you Arroyoshark for taking the time to post your findings.

Does anyone know if the Beartooth saddle ring safety delete made for the 336 will work in the Rio Grande?
"We have federal regulations and state laws that prohibit hunting ducks with more than three rounds. And yet it's legal to hunt humans with 15-round, 30-round, even 150-round magazines." Senator Dianne Feinstein (D-California)
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by Ranch Dog »

Thanks for your follow up report! Will keep an I on mine. In fact, going to pull the butt stock on all three of mine and check them.
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by Centaur 1 »

I actually worked for Knight's Armament Company in the R&D model shop. We designed and built rifle parts that worked just like the RG crossbolt safety. Part of designing a shaft that slides back and forth between two stopping points, is to also make sure that shaft doesn't rotate and cause another problem. Before you take the stock off the rifle, Grab the safety by whichever end is sticking out of the receiver, and try to rotate it. If the safety can rotate at all then the set screw is too loose. I tightened that set screw until the safety couldn't rotate, and now it's extremely difficult to move the safety on and off.

If I find out that the marlin 336 safety delete will work, this gun's going to get a saddle ring.
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by Ranch Dog »

Centaur 1 wrote:I actually worked for Knight's Armament Company in the R&D model shop. We designed and built rifle parts that worked just like the RG crossbolt safety. Part of designing a shaft that slides back and forth between two stopping points, is to also make sure that shaft doesn't rotate and cause another problem. Before you take the stock off the rifle, Grab the safety by whichever end is sticking out of the receiver, and try to rotate it. If the safety can rotate at all then the set screw is too loose. I tightened that set screw until the safety couldn't rotate, and now it's extremely difficult to move the safety on and off.
Thanks for the advice concerning the check. I haven't had any light strike problems with my rifles yet but it bears worth checking them.
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by Arroyoshark »

Centaur 1 wrote:Reading this post is what made me look at that screw, so thank you Arroyoshark for taking the time to post your findings.
You are most welcome, Centaur ! I was very frustrated with the Rossi Rio Grande and its non-firing issues. Likewise, mine just sat until I could be inspired to dig into it. It was the previous work by you and Tuco Ramirez that initiated my re-look into the matter. I may have just carried it to completion.

Glad my findings were of help to your Rio Grande.

While this model certainly is not Taurus/Rossi's best effort - sloppy is the word I reach for instead - it is a pretty lightweight example of a .45-70 which is what initially attracted me to the piece. I was coming from using an H&R Handi-rifle .45-70, so the idea of a lighter repeater was interesting to me.
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by Ranch Dog »

Arroyoshark wrote:While this model certainly is not Taurus/Rossi's best effort - sloppy is the word I reach for instead - it is a pretty lightweight example of a .45-70 which is what initially attracted me to the piece.
I was hunting a boar hog with this rifle a couple of evenings ago and just found myself admiring the firearm. It is too bad that Rossi did not give this series the attention it needed, but I also understand that it got as much attention as any of the other models. The thing with the 92 is that there is no competition if you are looking specifically for a 92 action. It is another story with a 336 based action and tales of woe with a manufacturers attempt to duplicate it can be a model killer. Better luck next time Ross :roll:
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Re: RG45-70 fail to fire/light hammer strike/no strike

Post by Arroyoshark »

Ranch Dog wrote: I was hunting a boar hog with this rifle a couple of evenings ago and just found myself admiring the firearm. It is too bad that Rossi did not give this series the attention it needed, but I also understand that it got as much attention as any of the other models. The thing with the 92 is that there is no competition if you are looking specifically for a 92 action. It is another story with a 336 based action and tales of woe with a manufacturers attempt to duplicate it can be a model killer. Better luck next time Ross :roll:

Michael, likewise have I found myself admiring the lines and weight of the Rio Grande .45-70. I've had some frustration with this arm at nearly every turn involving shootability and reliability. It cheated me out of a couple years of use. In the end I rendered a useable carbine, thanks to insight provided by members of this forum, including you. I would have loved it if your plan to use the reamer to open up the chamber throat had been feasible, as I would have checked out your chamber finish reamer. Instead I must trim my cases some 30 thousandths in order to chamber 405 gr. hand loaded cast boolitz. I had ordered a bunch of starline cases, and they warn on their website that their case mouths are thicker than other brands, but I ignored the warning. Rounds that would chamber in a friend's Henry .45-70 would not chamber and fire in the Rio Grande. I've now trimmed all the cases, eliminated the cross-bolt safety, whittled on the firing pin and the rifle performs like a show pony now.

I shot it from the bench a week ago, and with open sights and 405 gr. cast boolitz, backed by some Blue Dot powder I connected with steel gongs I set at 200 and 300 yards. That left me impressed and thinking I shouldn't be such a whiner ....
When sitting down to clean a gun, the first step is to load another gun - Elmer Keith
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