Going to attempt to solder steel sheet metal to an AR15 (M&P 15-22LR) bolt catch.  Will it work?

Okay boys and gals, here is what I am going to attempt to do:

Problem:
My Smith and Wesson M&P 22 (AR15 style 22LR semi auto rifle)  shoots great except for the fact that the bolt catch gets caught into the notch cut into the bolt when the last shot is fired, making it impossible to press the bolt catch to release the bolt.  In order to fix the problem on the field when loading, I must pull on the charging handle to get the bolt loose from the bolt catch, then load the next mag, wasting time and energy.  Since the bolt catch feature is the main reason I bought this rifle, I want to fit.  To my knowledge, this is not a wide spread problem with the M&P22, and may be limited to my unit.  


The solution:
After taking pictures and observing the problem, I came the solution that the part holding the bolt back will need to be ~0.100 wider to prevent the bolt catch from going into the notch cut into the bottom of the bolt, thus preventing the two parts from binding.  The original plan was to mill out an entirely new slightly oversized bolt catch from steel barstock, but unfortunately, I do not have access to a mill at this time, and this route will require hardening and finishing, which requires lots of time and equipment I do not have.

I ordered a spare bolt catch to take measurements on from S&W, and plan to modify the spare so I do not need to remove the one in the rifle for now. My current plan is to cut a notch for steel sheet metal ~0.125 thick to make the bolt catch slightly oversized in the critical area, then file down to size.  To secure the steel sheet metal, I plan to solder it on the bolt catch.  I have a propane blow torch, some copper pipe plumbing solder, some brownells high temp solder (need to turn the garage upside down to find that one), some flux, and some pliers to hold onto the part.  

My Question:
I know the bolt catch is made from investment molded cast steel, but have no idea what grade.  The sheet metal I plan to solder onto it is CRS 1030.  My question is, will I have  a problem soldering these two materials together?  I know castings often have problems when trying to weld together, but will cast steel and steel sheet metal bond together?  If I can't find the Brownells high temp gunsmithing solder, will regular copper pipe solder work?

While waiting for a response, I will be gathering materials.  I plan to get this done this afternoon.  As always, speedy responses are welcome!

ETA:  Fixed the problem by using a piece of paper clip that I cut to size and placed it in the spring detent of the bolt catch, preventing the bolt catch from rotating too far in, causing the malfuction.  Will do a live fire test tomorrow at my first Appleseed class, and will post pics and more details later.  Thank you everyone for your help!

no.
no.
no.

You can only solder metal well if the solder melts below the melt point of the base metal.  otherwise you will alter the base metal properties.  If the metal goes full cherry then you have a potential failure since the alloy can form all sorts of wonderful crystalline combinations.

I'm a mechanical PE who solders bike frames ALL the time.  I deal with 4130 mostly and I would not do this without the RIGHT equipment.  A propane torch will distribute the heat too much and you will have to heat up too much of the base.    You can only do this right if you get a torch with a very precise nozzle.


Mill the part out and abandon this recklessness.

Cant you just send it back to S&W for warranty repair?

Thank you for saving me from my own stupidity  I was going to sporterize/ bubbadize my AR 22LR while I was at it

That said, still don't have access to a mill for the foreseeable future, so...

Now, say I have a notch cut into the bolt catch, the sheet metal is bent to the correct contour, and both parts are properly degreased with brake cleaner and handled with gloved hands.  What is the best way to glue these parts together?  JB Weld?  Red Locktite?  A makeshift rivet through both parts?

ETA: The reason why I don't want to send it to S&W is because of the wait, possibility of loosing it in transit, and the possibility of waiting so long only to have the problem left unfixed.  If all else fails, I will send it to them with the original bolt catch installed.

So an aftermarket part is causing the problem?

Why not put the original part back in and be done with the whole thing?

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If you've got steel cherry red to solder with regular solder, you're doing it wrong.



To the OP:



Before you go redesigning your rifle, you may want to ask the manufacture if there's anything they can do as well as if this is the intended operation of the rifle. Some firearms are designed to have a new mag inserted and then operate the bolt handle. I'm not familiar enough with the Smith .22s to offer an opinion in this particular case.



If the bolt catch is catching and cannot be disengaged, could you change the angle a bit on the engagement surfaces so that they slip apart more easily?

In before you become a meme.

don't be a pussy grind that bitch down and weld it back up.

But first show them who is boss.  Cut that fucker in thirds with a bandsaw first!





 

And post pics

You mean like this

Everything is factory, factory magazines (second generation with blue followers), and factory bolt catches.  I got the second bolt catch from S&W.

Grinding the engagement surfaces won't do anything.  The problem is that the part of the bolt catch that holds the bolt back when the last shot is fired is too narrow and gets caught in the grove cut into the bolt. My solution is to make that part wider to prevent it from going into the bolt.






Yes.  If all else fails, I will throw a sissy fit and proceed to cut up my rifle and post pics.  I do not have a band saw, so I will do the same with a hacksaw and dremel.

don't discount the possibility that the original part may have been out of spec, and the replacement may be proper, and fix the problem with no more effort than a swap.  at least, that's what I'd hope for.

If everyone elses works right and yours doesnt, get S&W to fix it.  Stop wasting your time.

He's not asking to solder a bike frame where failure could be catastrophic in nature.  He's asking about an MIM part that has absolutely no bearing on the function of the rifle if he removed it completely.  It's ancillary and nothing he could do to it could influence the inherent safety of the rifle.

You're being ridiculous.

OP, there's no reason you can't do what you're proposing.  When you ask, "will it work?" the answer is another question: "Can you solder for shit?"  

Clean the part of any coating or finish.
Clean the piece you want to add.
Wipe some flux onto either piece, on the joint face of each.
Clamp them together with a piece of leaf solder in between the joint.
Heat evenly until the solder flows out of the joint.

Test and file to fit.

wasnt there someone that designed a bolt catch for .22 uppers last year? i forget who it was but it was a huge thread. i wish i had tagged it for my upper.

TAG!





 

In for impending WECSOG dremel action...

Man i lost it  

 

Billy always says - Mighty Putty.

send it back.

Have you thrown it down the driveway yet? Just sayin'.

Thanks.  Might have some spare time to do it tomorrow.  Will post pics and AAR if I do.


That is for older style AR 15 22LR conversions that use black dog style magazines.  I think Spike or CMMG had some interest in this, and are selling there own versions.

The S&W M&P15 22LR that I have is 22LR from the factory, and uses a completely different magazine and internal parts, and thus, is not related to the bolt catch you speak of.  

Would if I had a $500 welder to go with it


Be patient


Yes.


Won't work after repeated impacts.

Won't do much good.  The M&P is made of fiber reinforced plastic, like the Carbon 15 from Bushmaster.  


Sorry, didn't catch that the first time around.  Advanced reading comprehension I have my ass

My S&W 22LR rifle operates exactly like the centerfire AR15 counterpart.  When the last shot is fired, the follower of the magazine pushes the bolt catch up, which in turn holds the bolt back.  Replace with loaded mag, press bolt catch and fire.