H&R 940 .22LR revolver - hammer won't lock back

[monkeylizard]

I have an H&R 940 .22LR revolver and the hammer no longer locks back to shoot it single action. It will work with double-action, and while I haven't tried it, I suspect I could shoot it old cowboy movie style by holding the trigger and repeatedly cycling the hammer. The timing is good on it and locks up tight. It's not worth what a smith would charge me to fix it, so I'd like to try it myself. I've never done any work at all on revolvers (this is the only one I have). Any advice on where to start?

[xsubsailor]

Here's a starting point.

 

http://www.gunpartscorp.com/Manufacturers/HarringtonRichardson-33274/Revolvers-36449/940-38114.htm

[Dolomite_supafly]

I would hose it down with WD40 and let it set for a few minutes. Then use high pressure air to blow it out. Repeat a few times and I bet it will start working again.

[graycrait]

First thing is find screw drivers that exactly fit the slots of the screws on your revolver.  Then take that thing apart on a light colored towel. Take pictures every step of the way so you can go in reverse.

http://www.gunpartscorp.com/Manufacturers/Revolvers-36449/940-38114.htm

I doubt it is something you can fix, you will likely have to replace something.  If you can't find the part from Numrich (above link) then try Bobs Gunshop:

 http://www.gun-parts.com/harringtonrichardson/

If you can't find the part at either of those places I wouldn't be suprised if you could find it with Jack First Gunshop: (605) 345-9544.  Jack First doesn't have online ordering but if you call them and know what you want for what you want there is a good chance they will have the part.

 

 

 

Edited May 16, 2016 by graycrait

[xtriggerman]

The first thing to check is the single action sear. It is #27 on the schematic. Visually, you can see it mounted at the trigger guard/frame junction behind the trigger. Take a small screw driver and push it back into the face of the trigger guard and quickly slip the driver off. The little bit off reward movement back, should "snap"  back freely from the sear spring #28. As you thumb cock the hammer back, you should see this sear move back toward the guard and jump forward slightly once the hammer obtains single action position. Holding the hammer back, get a tiny screw driver behind the sear and force it forward and then let the hammer up. The hammer should hang or stall in the single action position while you put a little forward pressure on that sear. If in fact the sear is working freely with noticeable spring tension and the hammer is still not holding back, either the sear tip where it engages the hammer is worn and/or the hammer single action sear cut is wore out. It is possible that enough dirt filled oil could hamper the action of the sear spring and make the sear sluggish enough as to where it is just not engaging the hammer. That is why I described how to over come the dirt by putting slight pressure with a screw driver while you put the hammer into single action position and see if the hammer will hold back on its own while pressure is applied behind the sear.

  As far as you taking it apart, You would need to have knowledge on how to make and use slave pins to reinstall the trigger assembly. If you know how to do that, your probably going to be OK replacing the hammer or sear.

Edited May 17, 2016 by xtriggerman

[graycrait]

great points xtriggerman and Dolomite.  Sometimes I've used both nails or drill bits as slave pins.  I've also used punches as slave pins.  I have also soaked whole handguns in solvent then used compressed air to blow gunk out.  If you have a friend who has an ultrasound cleaner that will fit your revolver you could try that first, just stick the whole thing in the ultrasound tank after you take off the grips.  

You might want to look at the schematic for internal plastic parts.  I was looking at a youtube video of a different model of H&R revolver and it had a plastic internal piece that caused a different issue.

One thing I found out is that there was some hand fitting of some/many parts in older revolvers and even if you need and find the replacement part it can be hard to hand fit the part.  In a couple of instances in my case it was beyond my skill set to hand fit the part. 

Edited May 16, 2016 by graycrait

[Jeb48]

I would never use WD-40 on any part of a gun, it is not a cleaner solvent and can gum things up worse over time. There are very good clear solvents made for gun use if you think the problem is a gummed up mechanism.

[Ugly]

My S&W 686 bound up one time, I took it apart and found the slightest amount of gunk and dust in the mechanical area. Cleaned it out and it is as smooth as butter. 

It could be that simple. 

[graycrait]

Not to nit pic or whatever, but WD40 used as a cleaner or water displacer, not as a lube, can clean up crazy junk.  I used it once to clean some stain off a friend's car interior where everything else I tried didn't work.  I'll bet WD40 would be cool to use in a ultrasonic cleaner.  I suppose so would Goo Gone or Goof Off. I wish I hadn't given my ultra sound cleaner away when I downsized my gun accumulation.  If I still had the ultra sound cleaner I  would try some of these mentioned products including Ballistol, the full can of which I have sitting on the shelf with about 15 other like-products, including a good part of a   gallon of CLP I am unlikely to use up this millennium. 

[xtriggerman]

WD40 can be a good cleaning agent and a lot of folks use it for that as Dolomite pointed out. I'v used it to clean off SKS cosmo after a heat gun more than a time or 2. But what you do not want is any WD40 residue within a critical part on part movement inside an action. WD40 will dry out over time and leave behind a fine waxy type film.  In Gunsmithing school, WD40 was used exclusively in washing down freshly blued parts out of the water displacement oil dip tank. In that application, nothing works better than WD40 for rubbing off residual surface oxidation from a fresh blue job. But, that WD40 was also rubbed off any internal moving parts and lubed with an appropriate gun lube. Its a gun bench standard......when used appropriately. 

[Dolomite_supafly]

I actually use WD40 to keep guns running longer than they really should. I always have a can at the range for when a gun starts to malfunction from being full of crud. A few squirts of WD40, a few racks of the bolt/slide and it will keep you from having to clean it until you get home. I had one 22 AR that was never cleaned in at least 10K rounds, and suppressed at that, all I did was shoot it full of WD40 and continue to shoot. My 22/45 had at least 5K of rounds through it between cleanings using WD40 to keep it running. Anyone who has shot with me knows that my stuff stays dirty from use.

 

When I do decide to clean my guns the first thing I do after disassembling is hoes the gun down completely and let it sit. Then I use a brush and some more WD40 to loosen everything up. Then I use high pressure air to blow everything out and then I am done.