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Posted By: Shotgunlover BSA hinge - 01/23/16 10:42 AM
Does anyone know whether the hinge (cross) pin on BSA boxlocks is threaded with a left hand thread?

Reason for asking is the failure to remove the pin by a professional who treated it as a normal thread (ie right hand) but failed to budge it even with specially made tools.

It crossed my mind that perhaps the pin is threaded with a left hand thread and he might have been tightening it unwittingly.
Posted By: nialmac Re: BSA hinge - 01/23/16 01:57 PM
That can't be ruled out but very, very unlikely. Generally there has to be a good reason for left hand threads. In this case the gun maker would also have to make a LH tap. Possible, but why? Soak it in penetrating oil, heat it up, use an impact driver, do all the stuff that top notch screwers do to get unscrewed.
nial
Posted By: Der Ami Re: BSA hinge - 01/23/16 03:55 PM
Be sure to check very closely that there is no screw or pin, holding the hinge pin in place.
Mike
Posted By: nialmac Re: BSA hinge - 01/23/16 08:09 PM
Mike, I would hope that's the first thing a "professional" would check since it's not uncommon to have a set screw going cross wise from the front of the knuckle into the hinge pin. Can you imagine a "professional" who missed that. Scary, boys and girls.
nial
Posted By: gunman Re: BSA hinge - 01/24/16 12:15 PM
[quote=nialmac]Mike, I would hope that's the first thing a "professional" would check since it's not uncommon to have a set screw going cross wise from the front of the knuckle into the hinge pin. Can you imagine a "professional" who missed that. Scary, boys and girls.
nial


Actually yes
Posted By: gunman Re: BSA hinge - 01/24/16 12:19 PM
Joint pins can be an absolute nightmare to get out on occasion .
Some are so loose they virtually fall out and some mo matter what just dont want to budge without some serious brute force .Not unknown to have to be drilled out when all else has failed .
Posted By: damascus Re: BSA hinge - 01/24/16 08:34 PM
Hi shotgunlover.

What I am about to describe is somewhat brutal but it has an extremely good chance of helping you remove a seized rusted and other reasons that make screw threads virtually impossible to move. It does involve heat but in a very specific way applied to the joint pin its self. You will need a stick welder not a Mig or Tig just a standard coated electrode welder capable of providing a couple of hundred amps. You attach a carbon rod (the copper coated type used for ark brazing) to each output cable of the welder then apply the carbon rods to each side of the guns hinge pin then turn on the current. You will find that the steel pin will start to heat up because the steels electrical resistance is far higher than the copper wire of the welder leads plus the carbon rods, If you keep the connection on long enough you can get the joint pin red hot. This method has been used for many years for removing rusted or generally seized bolts nuts and studs but things do get hot so not for the feint hearted!
Posted By: Run With The Fox Re: BSA hinge - 01/25/16 12:44 AM
Originally Posted By: damascus
Hi shotgunlover.

What I am about to describe is somewhat brutal but it has an extremely good chance of helping you remove a seized rusted and other reasons that make screw threads virtually impossible to move. It does involve heat but in a very specific way applied to the joint pin its self. You will need a stick welder not a Mig or Tig just a standard coated electrode welder capable of providing a couple of hundred amps. You attach a carbon rod (the copper coated type used for ark brazing) to each output cable of the welder then apply the carbon rods to each side of the guns hinge pin then turn on the current. You will find that the steel pin will start to heat up because the steels electrical resistance is far higher than the copper wire of the welder leads plus the carbon rods, If you keep the connection on long enough you can get the joint pin red hot. This method has been used for many years for removing rusted or generally seized bolts nuts and studs but things do get hot so not for the feint hearted!
Batshit. You know as much about the SMAW aka "Stick" rod electrodes, polarity settings, carbon, copper and mild steel resistance to amperage flow, as old Neville Chamberlain knew about what made Hitler what he was- You can't do thus, as you describe, with the usual Lincoln Electric red "buzz box"transformer arc (not ARK-think Noah and the Bible with that spelling) welder most farmers and hobbyist metal workers here in the colonies have- why, might you ask, my ill-informed Limey- because the buzz box welders- fed with 220 single phase input current and a 10% duty cycle welding machine (except for the 75 amp setting-encircled on the front panel, by the way_ you need a 440 3 phase input transformer or rectified DC welder with a 100% duty cycle- with at least a 350 ampere output at 100% duty cycle- such as metal fabrication plants that tend to join heavy gauge steel with 7014 or 7018 AWS code rods, 3/16" to maybe 1/4" in dia. and run in the 1G or downhand position- If some beginner here who doesn't know this tries your suggested proceedure, he will not be pleased with his end results==
Posted By: Franc Otte Re: BSA hinge - 01/25/16 03:41 AM
Fox,
I find it pretty hard to believe that our learned friend, n my fellow countryman , Damascus has posted a load of bullshit...I'd bet what he said, if done as he says , will work fine.
Perhaps its the Separated by a common language thing?
franc
Posted By: damascus Re: BSA hinge - 01/25/16 10:29 AM
Well fox you never cease to amaze me, you have thrown all the technical though miss guided chaff in the air. Possibly caused by the “Not thought of by me syndrome” and my final word on this subject is this, high current applied using low resistance conductors through as in this case steel with more resistance than the conductors will always produce heat depending on the current flow applied, all governed by the emf. THIS IS HOW A SPOT WELD IS PRODUCED in steel.
So don’t knock it if you have never tried it please. Because what I described in my posting was a very large spot welder without the timer as you should know!!!!

Damascus
Posted By: Shotgunlover Re: BSA hinge - 01/25/16 03:24 PM
Looked again at the action, the gun belongs to a friend. There is no screw on the knuckle to act either as retainer to the pin or as anchor for the extractor cam. The cam appears to be one piece with the action knuckle.

I do not exclude rust on the threads as a cause for the sticking, however there is no hint of visible rust anywhere on this BSA and overall it is in excellent shape.

Failing pin removal it seems that bringing it back on face will have to be done solely via filling the hook.

Still would like to know about the that thread though, just academic like, whether it is left or right hand thread.
Posted By: mark Re: BSA hinge - 01/25/16 04:07 PM
If the BSA has dovetailed lumps welding the hook is not a good option. Welding across a solder or braze joint will bring no joy!
Posted By: Shotgunlover Re: BSA hinge - 01/25/16 05:32 PM
No welding, not when I can help it! A shim is a better option and follows the adage "do no harm". The setback required is in the region of 6 thou, easily within the capabilities of shim stock. A shim can be soft soldered and stay in place if the prep work is done properly. I used a Pape that had a shim in place for 30 years.
Posted By: nialmac Re: BSA hinge - 01/25/16 06:52 PM
I have in my past watched machinists with way more patience than I work away at a stuck bolt for what seemed like forever. Soak it, heat it, try it again and again. I would have been blue in the face and swearing that it has to be drilled out. Lo and behold, out it comes. Makes you want to kick the guy who got it out.
nial
Posted By: gunman Re: BSA hinge - 01/25/16 07:18 PM
Impact driver and a 2 pound hammer!
Shimming may give you .006" at the back of the hook but it will give you .012" off the diameter so the chances are the pin will nor reach the back of the hook and so not have a proper bearing .
Posted By: Shotgunlover Re: BSA hinge - 01/25/16 10:39 PM
Well, the shim will be smoked in, the top and bottom areas scraped so as to have the fullest contact possible with the pin.

The thought of the impact driver is scary. I guess it is all comes down to familiarity and experience as with any process.

In the meantime it is anointed twice daily with penetrating oil hoping that it will do the trick gently.
Posted By: keith Re: BSA hinge - 01/25/16 11:36 PM
Originally Posted By: nialmac
I have in my past watched machinists with way more patience than I work away at a stuck bolt for what seemed like forever. Soak it, heat it, try it again and again. I would have been blue in the face and swearing that it has to be drilled out. Lo and behold, out it comes. Makes you want to kick the guy who got it out.
nial


Yes, yes, yes! The most important tools you can have for removing a frozen screw on a gun are patience and a really good penetrating oil. Sometimes extreme measures and great force are required to get things moving, but if you do that with threads that didn't get a chance to get lubricated with penetrating oil, you risk galling or stripping them. Then you've really got problems that no amount of heating or soaking is going to help.

Just as nialmac says, I have had screws that defied all of my efforts of soaking, heating, rapid freezing, vibration, etc., so I just soaked them down with a GOOD penetrating oil, and wrapped the area with Saran wrap to keep it from evaporating, and set it aside. Often, when I went back at it 5 or 6 months later, it broke free as if it was never stuck. We have had discussions about GOOD penetrating oils here before. To me, Kroil isn't even in the top 50%.
Posted By: LeFusil Re: BSA hinge - 01/26/16 12:07 AM
Originally Posted By: mark
If the BSA has dovetailed lumps welding the hook is not a good option. Welding across a solder or braze joint will bring no joy!


Huh? There are literally thousands of dovetail lumped guns that have been rejointed by welding the hook. I've never seen an example that had the lumps come loose either. I've also seen chopper lump barrels that have had their hooks welded. Or...are you talking about barrels put together like a model 21? The BSA design is actually a combo of both. 99% of Damascus barrels are dovetail lump construction.
Maybe just too over generalized of a term and it caught my attention.
Posted By: mark Re: BSA hinge - 01/26/16 01:42 AM
Originally Posted By: LeFusil
Originally Posted By: mark
If the BSA has dovetailed lumps welding the hook is not a good option. Welding across a solder or braze joint will bring no joy!


Huh? There are literally thousands of dovetail lumped guns that have been rejointed by welding the hook. I've never seen an example that had the lumps come loose either. I've also seen chopper lump barrels that have had their hooks welded. Or...are you talking about barrels put together like a model 21? The BSA design is actually a combo of both. 99% of Damascus barrels are dovetail lump construction.


Maybe just too over generalized of a term and it caught my attention.


I'm talking about solder contaminating the weld.
Posted By: 2-piper Re: BSA hinge - 01/26/16 12:33 PM
Most, though admittedly "Not All" dovetail lumps are brazed on, not soldered. In either case there should be no solder in the hook.
Posted By: Der Ami Re: BSA hinge - 01/26/16 03:13 PM
Keith,
Thanks for the saran wrap trick, I never heard of that one before. Half/half ATF and Acetone is a very good penetrating oil, I wonder how the acetone would react with saran wrap.
Mike
Posted By: mark Re: BSA hinge - 01/26/16 06:17 PM
On BSAs and model 21s the lumps are dovetailed and soldered. the solder joint runs right down the middle of the hook.
Posted By: 2-piper Re: BSA hinge - 01/26/16 07:05 PM
Quote:
On BSAs and model 21s the lumps are dovetailed and soldered.

True, "BUT" that is a dovetailed Chopper Lump, not a dovetailed lump. On a dovetail lump the lump is all one piece & an entirely separate piece from the barrels. Inso far as I am aware chopper lump barrels have a joint in the lump whether dovetailed or not. Those which are not dovetailed are normally brazed, which I believe would likewise affect the welding.
I do know that some BSA guns had the dovetailed chopper lump, do not know if the all did or not. When just the term dovetail was used I was assuming this meant otherwise. The fact it is chopper lumped is what puts the joint in the lump, not the dovetailing.
Posted By: Gunflint Charlie Re: BSA hinge - 01/26/16 08:50 PM
These drawings from Burrard's "The Modern Shotgun" were scanned and posted by someone here in 2007, but the host site no longer has those images. I printed copies back then and added the handwritten notes. Scanned them again today for posting here, sorry for the weak images and text.

Jay

Posted By: 2-piper Re: BSA hinge - 01/26/16 09:41 PM
Jay;
Thanks for the illustrations. as can be seen in fig 4 the lump is a solid & separate piece in the dovetail lump. In fig's 7 & 8 are the two types of chopper lump barrels. The seam down the center is obvious in these. The chopper lump barrels thus, whether dovetailed or not, are the ones which could give problems with welding. I believe that when Winchester designed the model 21 they [laced the dovetail farther forward so it was necessary to increase the breeches as much as BSA did. According to Burrard this was a major complaint with the BSA in that it had very wide spaced barrels due to the dovetail.
Posted By: Shotgunlover Re: BSA hinge - 01/27/16 01:41 PM
To clear some apparent confusion. The BSA in question definitely has dovetailed CHOPPER LUMP barrels. I cannot discern even with a powerful lens whether the joint is solder or braze.

Looking at the construction I can see why the barrels are wider than "regular" chopper lumps. In the usual chopper lump joining metal is removed from the inner surfaces of the barrels, the lump sides, to bring them closer together. The braze is strong enough to form the middle layer into one solid wall which can be no thicker than the external barrel walls.

In the BSA-Mode 21 setup no metal is removed from the inner/middle layer. The same applies to monobloc barrels. The barrels must be totally round when inserted into the monobloc there is not chance to file the middle part to bring them closer together.

You have to wonder then whether the insistence on chopper lump and the dovetailed lump (the one inserted under the barrels) was to keep the gun slim and elegant, rather than stronger.

Personally I would rather opt for barrels that are a millimter or two wider at the breech ends and stronger.
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