Question for the gunsmiths

So kind of unrelated, but you can buy shim stock in whatever thickness you want, .002", .005", .007", .010", etc. Brass, stainless, etc. Hell of a lot easier to draw a couple of circles and cut them out with a pair of scissors than to try to machine a .005" thick washer on a lathe, lol. Then you know you're getting uniform thickness.
 
So kind of unrelated, but you can buy shim stock in whatever thickness you want, .002", .005", .007", .010", etc. Brass, stainless, etc. Hell of a lot easier to draw a couple of circles and cut them out with a pair of scissors than to try to machine a .005" thick washer on a lathe, lol. Then you know you're getting uniform thickness.

scissors kinda work like crap because you'd have to bend it for the inner cutout but I expect that if it's clamped to a wood block, a mill should be able to cut it out? (have a Taig CNC here - I think it should be quite capable of that)
 
I shimmed a barrel on a Winchester 1894 (circa 1912) that some gorilla used a pipe wrench on. The barrel was overtightened enough that once removed, just tightening snugly by hand would overclock the sights.

Took several tries with various shim thicknesses, tightening and loosening, to get the right one figured out. I could only get one attempt with a particular shim. Once tightened, if you broke it loose, it always damaged the shim. Then I just cut out a final shim and slammed it together. You can't tell it's there.

ZbWd5Vo.jpg
 
Rather than try to make a thin shim, I have machined the barrel shoulder back and made a breeching washer, perhaps 0.100 thick.

I would do that and have on firearms that aren't ''appearance'' sensitive. Much less time consuming, but even then, you need to be careful when torqueing up or the washer will bulge just enough to leave a visible ridge.

I don't like using washers unless it's absolutely necessary. Same goes for dimpling either of the faces.

Just depends on the job.
 
I shimmed a barrel on a Winchester 1894 (circa 1912) that some gorilla used a pipe wrench on. The barrel was overtightened enough that once removed, just tightening snugly by hand would overclock the sights.

Took several tries with various shim thicknesses, tightening and loosening, to get the right one figured out. I could only get one attempt with a particular shim. Once tightened, if you broke it loose, it always damaged the shim. Then I just cut out a final shim and slammed it together. You can't tell it's there.

ZbWd5Vo.jpg

That's a nice job, but it doesn't always turn out so nice, even if you're extremely careful.

As for Scotty454 cutting shims from shim stock, most folks don't have the right tools to do this properly.

I have a couple of circle punches that were modified by chucking them up in a lathe and turning the inside diameters to be a few thou larger than the tenon diameters on Lee Enfield barrels and on Remington tenons.

They work well for the center hole, which is the toughest to cut.

I also made up a mandrel to fit into the center hole, with two faces, one that fits in the center and another that overlaps the same as the barrel diameter, that I can use as a template to scribe a concentric circle around the inner opening. It works just fine but it's finicky and if care isn't used, very visible when locked up.

The other issue with shims is keeping them centered on the tenon while applying tourque, they have a tendency to shift.

One fellow I know uses wire that he wraps around the tenon shoulder juncture. It seems to work OK and doesn't leave a visible gap.
 
If I understand this right, the barrel has gone past the index mark, and headspace is now below minimum. Is this correct? I would like to know the diameter of the barrel shank (ahead of the shoulder) first. If the shank is 1.150 or less, there is not enough shoulder to tighten up against the receiver. In this case, I would make a nut and thread the barrel for it to set and maintain the headspace. If the shank is over 1.180, it should be large enough and I would then cut the shoulder back and use a spacer to establish correct headspace.
 
Back
Top Bottom