Texas Hunting Forum

Soldering Scope Base to Action?

Posted By: Wildhorse

Soldering Scope Base to Action? - 08/12/15 01:16 PM

Has anyone ever soldered their picatinney rail, or any other scope base, to their rifle action? If so, what method did you use and who did it? What all is required?

The reason I ask is that someone on here was discussing producing a new action with the action and rail made separately and later permanently attached by welding or soldering. I thought that sounded like a fall-down-the-mountain proof way of attaching a base so the idea appealed to me.
Posted By: J.G.

Re: Soldering Scope Base to Action? - 08/12/15 01:38 PM

I belive TIG welding is what is required, soldering is not strong enough. I wouldn't be scared to TIG weld them together. Some fine actions used to be put together this way, but now the action and pic rail are machined from one piece of steel.
Posted By: REALKILLER

Re: Soldering Scope Base to Action? - 08/12/15 01:43 PM

You cant drill and tap it. seems like if you solder it or weld it, it may be your baby after that. May even be hard to sell if you wanted to do so in the future. I think the recoil would break solder loose.
Posted By: Precision_Shooter

Re: Soldering Scope Base to Action? - 08/12/15 01:57 PM

Remington has been brazing (soldering) their bolt handles on forever. And there have been many instances where the solder has broken free when cycling the bolt. If you get a good strong bond between the 2, you may be ok, but for me, you are pretty much assured a strong bond when it's welded. TIG welding would be the way to go...
Posted By: SingleShot85

Re: Soldering Scope Base to Action? - 08/12/15 02:21 PM

seem like a lot more unnecessary work to produce an action with a built-in rail only to go back and permanently attach it, will be more costly in the end..... you have choice or flexibility w/ a detached rail, you have less "moving parts" with a built in rail all personal preference neither is better....

kt
Posted By: Wildhorse

Re: Soldering Scope Base to Action? - 08/12/15 03:35 PM

Originally Posted By: Precision_Shooter
Remington has been brazing (soldering) their bolt handles on forever. And there have been many instances where the solder has broken free when cycling the bolt.


True. I've had a Remington 700 bolt handle come off in my hands before, so it sounds like TIG would be better.

Originally Posted By: FiremanJG
I belive TIG welding is what is required, soldering is not strong enough. I wouldn't be scared to TIG weld them together. Some fine actions used to be put together this way, but now the action and pic rail are machined from one piece of steel.


I wonder if TIG welding the base would cause issues with the temper of the receiver and, if so, whether heat sinking the action could avoid the need to re-heat-treat the receiver after the action is complete.

Originally Posted By: REALKILLER
You cant drill and tap it. seems like if you solder it or weld it, it may be your baby after that. May even be hard to sell if you wanted to do so in the future. I think the recoil would break solder loose.


You're probably right about the solder coming off with recoil. The reason I though soldering might work was because many rifles have their iron sights soldered onto the barrel. But, on second thought, those sights don't have to hold a heavy scope to the firearm under recoil, they just have to hold their own mass.

Not to worry about the non-cost-effective nature of this idea, I'm just posing it as an academic question, not that I'm about to bite it off as a real project. If I feel like my base is too weakly attached I'd probably start out by drilling and tapping the action to accept a larger screw, which would provide more bearing surface to ensure that the base is securely attached.
Posted By: TDK

Re: Soldering Scope Base to Action? - 08/12/15 03:40 PM

I have a ton of experience with soldering and its applications to gun making. Strength is no issue when done correctly using a Hugh tensile solder like sold by Brownells.

This being said why not drill and tap it?
Posted By: Cast

Re: Soldering Scope Base to Action? - 08/12/15 03:44 PM

Silver solder like the A/C guys use and a torch will be strong enough. Brazing will be stronger. Make some sort of alignment jig to hold it in place while soldering and cooling. Interesting thread.
Posted By: Wildhorse

Re: Soldering Scope Base to Action? - 08/12/15 04:08 PM

Originally Posted By: TDK

This being said why not drill and tap it?


I'm actually conceptualizing this idea as a supplement to also attaching with screws. So screw, AND weld/solder/braze, kind of like a belt AND suspenders.

My interest in this idea comes from my experience elk hunting. I've had buddy's fall on a boulder on top of their rifle. Horses could also fall or lay down on a rifle in the scabbard. Thinking about all the potential things that could happen to a rifle miles into the back country where no repair or replacement is possible leads me to be interested in ideas for eliminating as many potential points for failure as possible. Four little screws holding a scope on has just never inspired a whole lot of confidence that they might not end up being the weakest link.
Posted By: Wildhorse

Re: Soldering Scope Base to Action? - 08/12/15 04:09 PM

Originally Posted By: Cast
Silver solder like the A/C guys use and a torch will be strong enough. Brazing will be stronger. Make some sort of alignment jig to hold it in place while soldering and cooling. Interesting thread.


What is the difference between brazing and soldering?
Posted By: Cast

Re: Soldering Scope Base to Action? - 08/12/15 04:24 PM

Originally Posted By: Wildhorse
Originally Posted By: Cast
Silver solder like the A/C guys use and a torch will be strong enough. Brazing will be stronger. Make some sort of alignment jig to hold it in place while soldering and cooling. Interesting thread.


What is the difference between brazing and soldering?


Silver solder vs a brazing rod. Solder for aluminum receiver, brazing rod for steel. Everything else is pretty much the same.
Posted By: REALKILLER

Re: Soldering Scope Base to Action? - 08/12/15 05:31 PM

Im pretty sure once you screw it down your weakest link after that is going to be your scope itself. I hunt year round off the ground only. Needless to say that during my thousands of miles of walking there will be a few bangs and bumps along the way. A high quality scope will help you hold zero, but there isn't a scope out there that cant be knocked off zero. Ive always wanted to build a light protective cage around a scope. Now that's something you could build. kinda like a roll cage for a car. up
Posted By: TDK

Re: Soldering Scope Base to Action? - 08/12/15 06:35 PM

There is soft soldering, silver solder, and brazing. Silver soldering and brazing are considered the same thing, just depends upon which part of the globe you're on. Soft soldering is done at anywhere from 250°-600°. Brazing is usually done at around 900-1300°+. I'd recommend a higher temp soft solder in the 450-600° area.

If you're located in dfw I can give you a quick in person crash course on soldering.
Posted By: Korean Redneck

Re: Soldering Scope Base to Action? - 08/12/15 06:36 PM

I too am very skeptical of brazing or soldering. I'd imagine it ain't the strength of the braze and/or solder but adhesion to the steel that will ultimately be the problem. Even when u weld, if your temps are hot enough, then I thought that's were you'll have problems of the slag bonding to the surface of the parent metal.
Posted By: Cast

Re: Soldering Scope Base to Action? - 08/12/15 06:38 PM

I'm more worried about the heat warping the receiver. I think I would drill and tap it.
Posted By: TDK

Re: Soldering Scope Base to Action? - 08/12/15 06:42 PM

A mandrel in the raceway prevents warping. Color case hardening is done at 1450°, then quenched in 70° water. I've never warped an action. That being said welding would be more prone to warping die to uneven heat distribution.

High end custom makers usually tig weld bridges on the rear ring then drill tap the front.
Posted By: REALKILLER

Re: Soldering Scope Base to Action? - 08/12/15 07:09 PM

Ive had too many welders do a real quick and crappy patch job to my trailers to let anybody weld anything to a gun. They use the wrong rod, or don't get the surface clean enough and bam there you are stranded with a busted trailer on the side of the road. I would even go out on a limb and say that solder is a malleable type of material and I wouldn't want a weld holding my equipment to my gun with a softer than receiver material. smile
Posted By: J.G.

Re: Soldering Scope Base to Action? - 08/12/15 07:11 PM

Originally Posted By: Cast
I'm more worried about the heat warping the receiver. I think I would drill and tap it.


I wouldn't worry about that with TIG. The action is so robust you wouldn't have to penetrate even 25% deep into the action to get a steel pic rail welded to the action. And a good welder would make the weld look like a miniature stack of coins but only 3/32" wide.
Posted By: Cast

Re: Soldering Scope Base to Action? - 08/12/15 07:27 PM

Originally Posted By: FiremanJG
Originally Posted By: Cast
I'm more worried about the heat warping the receiver. I think I would drill and tap it.


I wouldn't worry about that with TIG. The action is so robust you wouldn't have to penetrate even 25% deep into the action to get a steel pic rail welded to the action. And a good welder would make the weld look like a miniature stack of coins but only 3/32" wide.


I can weld but the stack of coins is elusive.
Posted By: Wildhorse

Re: Soldering Scope Base to Action? - 08/12/15 08:02 PM

Originally Posted By: Cast
Originally Posted By: FiremanJG
Originally Posted By: Cast
I'm more worried about the heat warping the receiver. I think I would drill and tap it.


I wouldn't worry about that with TIG. The action is so robust you wouldn't have to penetrate even 25% deep into the action to get a steel pic rail welded to the action. And a good welder would make the weld look like a miniature stack of coins but only 3/32" wide.


I can weld but the stack of coins is elusive.


That would look so awesome! I kind of want to actually do that now just to see how sick the finished product would look.
Posted By: J.G.

Re: Soldering Scope Base to Action? - 08/12/15 08:29 PM

Originally Posted By: Cast
Originally Posted By: FiremanJG
Originally Posted By: Cast
I'm more worried about the heat warping the receiver. I think I would drill and tap it.


I wouldn't worry about that with TIG. The action is so robust you wouldn't have to penetrate even 25% deep into the action to get a steel pic rail welded to the action. And a good welder would make the weld look like a miniature stack of coins but only 3/32" wide.


I can weld but the stack of coins is elusive.


TIG welding is a dance. Two hands and one foot since I dont use the roller ball torch. No big deal if you have the machine set properly.

19 years of welding doesn't hurt either.
Posted By: Wildhorse

Re: Soldering Scope Base to Action? - 08/12/15 08:58 PM

Originally Posted By: FiremanJG
Originally Posted By: Cast
Originally Posted By: FiremanJG
Originally Posted By: Cast
I'm more worried about the heat warping the receiver. I think I would drill and tap it.


I wouldn't worry about that with TIG. The action is so robust you wouldn't have to penetrate even 25% deep into the action to get a steel pic rail welded to the action. And a good welder would make the weld look like a miniature stack of coins but only 3/32" wide.


I can weld but the stack of coins is elusive.


TIG welding is a dance. Two hands and one foot since I dont use the roller ball torch. No big deal if you have the machine set properly.

19 years of welding doesn't hurt either.


Do you think that could be done without compromising the action's original heat-treat?
Posted By: J.G.

Re: Soldering Scope Base to Action? - 08/12/15 09:12 PM

You will anneal the weld area during welding if it is not quenched afterward. The way to give you piece of mind after welding is to allow the weld to cool down from orange glow (estimated guess) is wait about 15 more seconds and quench in brine or oil. Water may or may not crack the weld. Again, you probably won't get the interior meat of the action steel hot enough to cause a problem. Quenching would just be insurance.
Posted By: QuitShootinYoungBucks

Re: Soldering Scope Base to Action? - 08/12/15 09:48 PM

I can do the stack of coins but it's usually dime-dime-nickel-quarter-nickel-quarter-dime instead of dime-dime-dime-dime-dime-dime. grin
Posted By: Wildhorse

Re: Soldering Scope Base to Action? - 08/12/15 09:59 PM

Originally Posted By: QuitShootinYoungBucks
I can do the stack of coins but it's usually dime-dime-nickel-quarter-nickel-quarter-dime instead of dime-dime-dime-dime-dime-dime. grin


Sounds like a custom signature to me, which makes it more exclusive and desirable.
Posted By: TDK

Re: Soldering Scope Base to Action? - 08/12/15 11:30 PM

By no means should you ever quench anything after welding! Let it air cool.

Welding is a toss up on the front ring. I would recommend properly annealing, rehardening, the tempering down to the correct hardness. Otherwise you will have inconsistent hardness levels in the ring which could leave to cracking. The rear rings isn't important as it's only purpose is a guide for the bolt.
Posted By: blackcoal

Re: Soldering Scope Base to Action? - 08/12/15 11:32 PM

Regarding strength, back in 1977 I had a welder use silver solder to attach braces to custom fuel tank which was then mounted to a rail dune buggy. That machine saw a great deal of hard action and stress of torque on both river mud and hard rock. Braces never came loose or cracked.
Posted By: REALKILLER

Re: Soldering Scope Base to Action? - 08/12/15 11:42 PM

Ive seen some beautiful welds done in the oilfield on pipelines and high pressure vessels, but they were done by pros that had to pass a welding test for that particular item to even be able to do the job. I welded some metal together to make v shaped metal with a torch and not a rig one time in metal shop in high school. The teacher looked at me and said nothing at all, but I could see the look in his eyes like he was too good to say that damn that looks good. It did, it was perfect little circles and even my friends thought it was cool. He was just that type of guy though. Ive always thought of solder like a glue and not a weld at all. up
Posted By: J.G.

Re: Soldering Scope Base to Action? - 08/12/15 11:49 PM

Originally Posted By: TDK
By no means should you ever quench anything after welding! Let it air cool.


I disagree. Ever is a stong word. And there have been occasions I have quenched welds. Look up the boiling point of water, brine, and oil and therefore the hardness/ brittleness achieved from each. Therea is also such a thing as an air quench. For instance, after welding cast iron with a nickle rod you have to keep it covered so that it won't air quench and crack.
Posted By: TDK

Re: Soldering Scope Base to Action? - 08/12/15 11:57 PM

I don't mess with guns made of cast iron, cant comment there. I will stick to my experience gained from making from scratch, heat treating, and welding on dozens of guns.

Most steels used in guns aren't air hardening with the exception of some of the newer steels like S7. 90% of actions are made of 4140 or 8620.
Posted By: J.G.

Re: Soldering Scope Base to Action? - 08/13/15 12:08 AM

And I will stick with my experience of working in a fab shop.

Exactly my point that those steels aren't air hardening. Wildhorse is worried about losing the temper of the action if a pic rail was welded on. And if you'll reread, I told him the action could be quenched if he was worried about annealed steel. I personally wouldn't be scared of it, but if he asked me to quench to give him piece of mind, I would but not in water.
Posted By: TDK

Re: Soldering Scope Base to Action? - 08/13/15 12:19 AM

Annealing wouldn't be my concern, additional hardening(introducing more carbon while the steel is at critical state, then quenching soon after) or inconsistent hardness resulting from welding then quenching would be. Oil quenching still increases hardness. It's safer to shoot an action slightly too soft than one that us too hard.

As a manufacturer I take additional steps to insure my ace doesn't get in the ringer. An individual isn't burdened with the same liabilities. I would run the action through a complete heat treating cycle if welding on the front ring.

Have fun playing gunsmith.
Posted By: J.G.

Re: Soldering Scope Base to Action? - 08/13/15 12:25 AM

I never said I was playing gunsmith, calling you ignorant, inexperienced, or uneducated.

A pic rail and an action are still just a machine made from a piece of steel. No one sprinkles pixie dust on them and makes them magical. And that is not to claim I am a good enough blacksmith or machinist to build one from bare stock. But welding a pic rail on top aint rocket surgery.
Posted By: TDK

Re: Soldering Scope Base to Action? - 08/13/15 12:55 AM

It's only a 50,000psi explosion and all the forces along with it 10" in front of your face.
Posted By: patriot07

Re: Soldering Scope Base to Action? - 08/13/15 01:20 AM

The area of the receiver directly around the weld will anneal, but there probably isn't any need to quench it. Even annealed steel is plenty strong in that area of the receiver.

What I would be worried about is warping the receiver. Warping is a very, very common problem with welding. It would not be worth the risk to me. If it ain't broke, don't fix it. Just tap the receiver and attach the rail with screws.

Just the opinion of a semi-humble mechanical engineer.
Posted By: Precision_Shooter

Re: Soldering Scope Base to Action? - 08/13/15 01:39 AM

Originally Posted By: patriot07
The area of the receiver directly around the weld will anneal, but there probably isn't any need to quench it. Even annealed steel is plenty strong in that area of the receiver.

What I would be worried about is warping the receiver. Warping is a very, very common problem with welding. It would not be worth the risk to me. If it ain't broke, don't fix it. Just tap the receiver and attach the rail with screws.

Just the opinion of a semi-humble mechanical engineer.


While I agree that warping is a common problem, a TIG weld represents the least possible chance of warping. Items warp from a continuous weld. Custom auto body fabricators TIG weld thin sheet metal all the time without warping them. It's all about spot welding and letting the metal cool between welds, which is the approach that should be taken if welding a rail on a hardened receiver...
Posted By: J.G.

Re: Soldering Scope Base to Action? - 08/13/15 02:43 AM

Originally Posted By: Precision_Shooter
Originally Posted By: patriot07
The area of the receiver directly around the weld will anneal, but there probably isn't any need to quench it. Even annealed steel is plenty strong in that area of the receiver.

What I would be worried about is warping the receiver. Warping is a very, very common problem with welding. It would not be worth the risk to me. If it ain't broke, don't fix it. Just tap the receiver and attach the rail with screws.

Just the opinion of a semi-humble mechanical engineer.


While I agree that warping is a common problem, a TIG weld represents the least possible chance of warping. Items warp from a continuous weld. Custom auto body fabricators TIG weld thin sheet metal all the time without warping them. It's all about spot welding and letting the metal cool between welds, which is the approach that should be taken if welding a rail on a hardened receiver...


^^Exactly^^
Posted By: J.G.

Re: Soldering Scope Base to Action? - 08/13/15 02:45 AM

Originally Posted By: TDK
It's only a 50,000psi explosion and all the forces along with it 10" in front of your face.


It is not an explosion, it is a burn.

And where does the vast majority of that occur? Again, TIG welding rails to actions is not a new thing.
Posted By: booradley

Re: Soldering Scope Base to Action? - 08/14/15 09:57 PM

If I wanted a permanently attached mount, I would have the receiver drilled and tapped and use red loctite on the mounting screws.
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