Good morning all. I have a problem for which I need advice. A customer just brought in a Brazilian which shoots nice groups,,,,4-5",,,, to the left.This was done from a pistol rest so shooter error is pretty well ruled out. What sort of a cure , if any, can you folks suggest. We tried a variety of factory hard ball and reloads, all with the same result. Nice groups, just in the wrong place.
Thanks,
Brian

One thing you might check is barrel rotation. If the barrel is slightly tweeked to tighten in the frame. If the front is where it should be, mount a WONDERSIGHT adjustable rear and make the correction. Only requires the use of the top side plate screw. Give her a try.

If the barrel is clocked properly, and still shooting off, the factory would use a lead babbitt bar and "adjust" the barrel as necessary to get it regulated to the sights.

Not something I would want to try for the first time. Not sure if they worked the frame, barrel, or both.

Check the muzzle crown of the bbl to make sure it is perfect.
Any imperfection or damage can throw shots.

Check the front sight to see if it's at 12 o'clock.
Look carefully from the muzzle end. If it appears tipped a bit towards 11 o'clock,,that's most likely the reason it shoots left.
The bbl can be tightened the few degrees to put the sight up top and most likely will bring the group closer to center..

Remove the bbl pin before tightening as a precausion,,though most can be done w/o doing that.

You can also over tighten it a tiny bit if the sight is at true 12 oclock and shooting left (or still shooting left after doing the above). That will bring the group to the right some more.
It takes very little to move the group and most never see the slightly off center blade.

*** You can't go too wild turning a S&W bbl to adjust groups as the ejector rod lock under the bbl will be out of position as you turn the bbl.
A few degrees rotation you can get a way with,,but that's about it.

Bending the blade itself is sometimes mentioned as a way to do this. It will work, but I was never a fan of doing such. Bending the bbl itself can leave you with the same problem as over rotation in tightening. The front lockup won't be in line anymore.
It can be done well on a Colt (no front lock-up) but on a S&W, I'd rather rotate the bbl than bend anything.

One other way we used to adjust the fixed sights was to thin the front blade. It worked well on the later mfg guns that have an 1/8" wide blade. Taking a touch off the correct side to in effect move the blade over to move the group worked well.

The older guns with the 1/10" wide blades don't leave you much to work with though and how much alteration you might want to do on a 1937 Bazilian Model S&W is a question only you and owner can answer.

Widening the rear sight notch can also gain some lateral movement along with the blade alteration but you have to really be conservative in the amount(s) removed.
Otherwise you end up with some pretty wierd looking sights.

A pinned front sight blade like on a Webley made it easy. They issued different sight blades with different offset dimensions for putting groups on center. You'r only talking a few .000" to change the impact point.
Such an alteration done in the original profile on the Brazilian may be an alternative if none of the other methods is possible.

"A customer just brought in a Brazilian which shoots nice groups,,,,4-5",,,, to the left.This was done from a pistol rest..."

At what range were you shooting? To me, that's not that great. I have a .44 Special Triple Lock, shipped in 1910, that will stack 'em into 2" or less at 25 yards.

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John 3:16
WAR EAGLE!

This may help you.

1950 Army - Out of Mothballs - Conclusion

You really have to move the front sight a very small amount to move POI 4 inches. I did the math on it when I was working on the 1950 and it's about 1.5 degrees. It will work and hard to tell when you're done. I am reticent to use the babbitt method - just don't like whacking stuff.

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S&WCA 1729

Thank you very much for the info on this Brazilian I have here . I will get set up and turn the barrel a tiny bit and see how we make out. I'm sure with your imput I can get it right!
Thanks again
Brian