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There are a couple of things that I’d like to talk about, that I hope may help some fellow neophytes to avoid some of the mistakes that I’ve made along the way. This .303 British is my 5th build and on each one I’ve made some mistakes and hopefully learned from them, and been smart enough not to do the same boo-boo twice. I certainly am no expert. I’m a rank amateur who spent his working life as a grocery store manager. I have no experience as a machinist, but I do own, and am able to operate, a South Bend 9” lathe. The little that I do know, I learned from books, from these BBS’s, and from asking questions of those who do know. I have two great advantages in this hobby of building double rifles. A good friend is a master tool and die maker and has a Bridgeport clone mill in his garage, along with enough tooling for it, to start a couple of tool and die shops. I am also on very good terms with a precision welder who is probably among the most skilled on this continent! Also, my father spent 35 years as inspector and instructor for the Canadian Welding Bureau, so I at least know the do’s and don’ts of soldering and welding. So, at the risk of possibly sounding pedantic to the many out there who know a lot more than I do about this subject, here goes.

1) This soldering business seems like a bit of a black art to some who have not done much of it, but it is not. The only solder that I use on these jobs is Hi-Force 44 from Brownell’s, along with their Comet flux. Hi-Force is 96% tin and 4% silver. This solder flows at 475F, well below the temperatures at which the properties of the steel would be adversely affected. In order to get solder to bond to steel, you MUST use an acid flux, which removes the impurities and oxides that form on the steel as it is heated in an oxygen-rich atmosphere. However, you cannot do the final installation of the ribs, using an acid flux, because the flux which gets trapped under the ribs will forever cause corrosion problems. The answer is to pre-tin both the barrels and the undersides of the ribs, using your solder and liberal amounts of flux. Using a soldering brush, brush away as much of the solder as possible while it is still fluid. The idea is to just deposit as thin a wash as possible of solder on the mating surfaces. Let everything cool to room temperature, then scrub away every vestige of flux in hot, soapy water, then rinse under hot, flowing water. Once everything is dry, clamp the ribs in place on the barrels, and devise a way (see my home-made jig in the photos) to hold the barrels and allow them to be rotated as needed. Now, you place a thin trail of powdered rosin, the same stuff that baseballers and violinists use, as a flux, along the seam between the rib and the barrels. As you heat the barrels, the rosin will melt and flow, by capillary action, into the joint. Now touch your solder wire to that area and it will melt and flow into the joint as well. Once you’ve finished the top rib, turn the barrels over and repeat on the bottom ribs. BE CAREFUL NOT TO OVERHEAT. You only want enough heat so that when you touch the solder to the barrels, out of the flame of the torch, the solder melts and is wicked under the ribs. It is possible to get the steel TOO hot so that the solder balls up on it and will not flow as you want it to. Once you’re finished, let everything cool on its own. Don’t try to accelerate the cooling process. This is a good time to go have lunch and a beer. Now you need to clean up all of the excess solder. I use VERY sharp wood chisels, applied carefully and lightly, and machinists’ stones, flooded with lots of varsol. You’ll need to shape the stones on a grinding wheel or a large, coarse, whetstone, in order to get into some of the tight spots. That’s it for soldering.

2) If you look at these photos of the quarter rib and front sight ramp, and compare them to the photos posted a few weeks ago, you will notice that they are higher now, by a considerable margin. Here’s why. I bought these ribs from Tom Ondrus, at Crown Press. They are the same as those that I used on my last build, the .450 #2 NE shown elsewhere here, and they are great ribs. However, when I turned these barrels in my lathe, I wanted to make them as light as was possible, consistent with strength. So, these barrels taper fairly abruptly from about 4 inches off the standing breech, down to about the 7 inch mark, then change to a gradual taper on out to the muzzle. Because of this, it took a fair amount of smoking and filing to fit the top rib tightly to the barrels. Now, once the ribs are soldered into place and cleaned up, I like to clamp the barrels in the vise of the milling machine, with the bores parallel to the bed of the lathe, then take as light a cut as is necessary across the top of the quarter rib and the front sight ramp. This ensures that these two surfaces are exactly the same height above the centre of the bores and that they are parallel to the bores. If you don’t do this, you can end up with some serious issues down the road with trying to get iron sights to match up. Worse still, if you plan to install a scope, you may end up with a quarter rib, with so much slope to it, that the scope does not have enough adjustment built into it to compensate for this. Well, when we did this, we discovered that the quarter rib was running downhill towards the muzzles, in a big way, due to the rapid taper that I had turned on the barrels. . Also, the front sight ramp was .200” lower than the lowest point on the quarter ribs. There was absolutely no way to rectify this problem by machining. At first, I was just devastated, and couldn’t see any way to fix this problem. It was as if this dream project had just come crashing down on my toes. However, we came up with a solution. I went and got a bar of ¼” x ½” cold-rolled steel. I cut it to the exact same lengths as the quarter rib and the front sight ramp. Then we milled it to the same width as the rib. Then, we cut a chamfer on the bottom edges of the two pieces and on the top edges of the quarter rib and the sight ramp, for welding into. Then, I clamped these pieces to the tops of the rib and the ramp and went to see the precision welder. This was a darned tricky job as Rick had to TIG weld to a rib that was being held to the barrels with solder that melts at about 450F. He would weld about ½” in a couple of spots, hand the barrels to me, I would run over to the compressed air hose and blast the area with cold air until it was cool again. It took about an hour and a half to complete, but we managed it. Now I went back to my machinist friend. We set up the barrels in the mill, faced off the quarter rib and front sight ramp, milled the short ramp that you see that creates the transition from the height of the Greener cross-bolt up to the height of the new quarter rib, and mortised the scope bases down into the quarter rib. Then I headed home and spent a day with various files, stones, and eventually 320 grit wet or dry paper, to dress off the welds to the point that you see them now. After that, I used a 50 LPI checkering file to matte the top of both the quarter rib and the front sight ramp, as you see in these photos.

The next time, which will probably be a .577 NE, I will have a quarter inch thick piece of cold-rolled welded to the top of the rib, BEFORE I install it! It would have been a heck of a lot easier to do this on the bench rather than on the gun. If, once the rib is installed, it turns out to be too high, it’s a simple matter to run a carbide cutter across it in the mill and to bring it down to the required height. LESSON LEARNED !!!!

Edited by ronvella (15/02/09 08:35 AM)

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