robert1804
Member
Several of my newer Smiths with pre-drilled optic mount holes have a problem with circular burn marks/deposits forming on the sides of the cylinder, directly under the sight blade screw. This screw is too short to fill the hole. Hot gasses from the barrel-cylinder gap reflect off that hole causing very hard deposits to form on the outside of the cylinder. It happens on my K, L, and N frame guns. On my stainless guns its not hard to soak and brush off, but on the blued guns it's much harder to remove. On older Smiths, the sight blade screw is well forward of the bc gap so these guns tend to evenly spread the hot gasses so you don't get a concentrated gas jet reflecting off the top strap.
I did a google forum search and found another post from a few years back about this problem. It said to get screws long enough to fill fill this hole. There was a link to Midway with the screws for the job. They are Forster .200" diameter head, 6-48 X 1/4" blued 10 pack. I put one in a 586. It needed only a little filing down to square the end and completely fill the hole.
Took this 586 to the range and fired 160 rounds. The fix works. There was still some circular deposit but it was now diffuse enough to wipe clean easily. The screws should work in N frames since they use the same length screw as the L frame, at least on my guns. Have not tried a K frame yet, those screws might be a little shorter so I can file them down as needed.
These screws have a little thicker head than the original screws, but their beveled head fits the seat in the sight blade so it is not marred.
I did a google forum search and found another post from a few years back about this problem. It said to get screws long enough to fill fill this hole. There was a link to Midway with the screws for the job. They are Forster .200" diameter head, 6-48 X 1/4" blued 10 pack. I put one in a 586. It needed only a little filing down to square the end and completely fill the hole.
Took this 586 to the range and fired 160 rounds. The fix works. There was still some circular deposit but it was now diffuse enough to wipe clean easily. The screws should work in N frames since they use the same length screw as the L frame, at least on my guns. Have not tried a K frame yet, those screws might be a little shorter so I can file them down as needed.
These screws have a little thicker head than the original screws, but their beveled head fits the seat in the sight blade so it is not marred.
