Need help removing front sight assembly from FR-8

[henschman]

Hello,

I am trying to remove the front sight assembly from my FR-8 Spanish Mauser. Has anyone done this before? I got the pin/eye hook out, but the front sight doesn't want to budge with a hammer and block of wood. Is it soldered? How do I go about getting this sucker off? Any help is greatly appreciated.

henschman

Information

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[Aragorn243]

I have read that they are soldered in place in addition to the sling eyebolt which may or may not play a role in securing it to the barrel. I replaced a broken eyebolt recently but made no attempt to remove the sight.

[Patrick Chadwick]

For those who only have two hands:

Arrange a solid vice that overhangs the edge of the table.

Remove the barreled system from the rifle.

Remove the tube below the barrel

The jaws of the vice must be padded on the sides, with hardwood blocks on the tops of the jaws.

Set up the jaws so that the barreled system is supported on the top (sight hood) and bottom extension, with the suport lines being close to the barrel. You need both hands free later, so close up the padded jaws just enough that the barrel is barely held, but can slide down, when you...

...Use a hot-air blower, set to a narrow jet, or a propane torch, to warm up the ring of the sight around the barrel to the point that the wood starts to char (remember Fahrenheit 451?). At this temperature, the solder must have melted, or at least have become pasty.

Put the blowtorch/air blower safely to one side, hold a short piece of hardwood plank horizontally across the muzzle and strike it firmly with a downwards blow of a hammer. The piece of plank ensures that the force of the blow is spread around the crown and not skewed. I use a copper hammer for such work, as it provides a very heavy but "dead" blow without any bouncing.

This method will remove foresight blocks with solder and/or keyways. And will not harm the barrel if you pay attention to the wooden "temperature sensor".

[henschman]

Thank you Patrick, I really appreciate it. That sounds like a very well thought out way of doing it. Now could I trouble you for your method of re-installing the front sight?

[Patrick Chadwick]

I suppose the method "whack it on with a great big hammer" isn't quite what you are after?

On sights that have keyways (e.g. M1917) the difficulty in removal is largely caused by grease used in assembly nearly a century ago, that has long since fossilized into a kind of resin glue. The best material to remove this is acetone and a coarse cloth. Which you should let dry off outside the house!

On soldered sights, it is a lot more tedious. In the electronics business, I used to use a thing called "solder wick". This is was essentially a very fine copper braid, rather like the outer conductor in co-ax cables. One used a sizeable soldering iron to press this onto the surface to be cleaned, and as the solder melted, capillary action drew it up into the braid, like a wick.

I still have some of this useful stuff, but in these days of throw-it-away microelectronics it may have disappeared from the market. Failing that, you are just going to have to remover the solder by scraping or rubbing with carborundum paper.

The socket in the foresight is easy - one can scrape around the inside without hazarding any visible surfaces. And you need to clean until you are pretty much down to blank steel. On the barrel it is a lot trickier, as it is difficult to scrape only the soldered part and not to scratch the neighboring sections of the barrel.

But if you have the foresight socket reasonably clean, then you should be able to get away without much scraping on the barrel. The cleaned-up foresight should be a push fit back onto the barrel. If you smear a tiny drop of solder paste on the inside of the foresight socket and push it on, then apply the blowtorch or hot-air gun, then as soon as the solder melts the foresight will slip on.

The trouble with this is that you also have to fit in the cross-pin. So you have to have a very good eye when placing the foresight or a lot of patience to get it right. Or make a jig to get it oriented correctly. A well-fitting pin ought to make the soldering redundant for civilian use, but it may have some play. Unless, like me, you have many years of precision soldering experience (electronics in the pre-IC days and model-making in my case) then I would suggest that you forget resoldering the foresight. Push on the foresight, line it up, and spread one end of the pin, if necessary, to make sure that it is a tight fit. If the sight still has some play, then a drop of Loktite, or even superglue, will hold it fast enough for target shooting. Both will soften with heat if you ever need to remove the foresight again.

Before someone writes in to say that glue will not retain its strength when the barrel gets hot - yes, i know that, but the glue really only has to fill any gap between foresight and barrel well enough to effectively jam the foresight in position so that it cannot rotate - it does not need much shear strength and practically no tension strength.

[henschman]

Thanks again Patrick for sharing your immense knowledge. I guess I see why most sporterizers just drill and tap on an aftermarket front sight, rather than re-installing the original! Oh well, I figure it's a chance to learn something new.