Lowering POI

[03RN]

I've loaded up a bunch of 158gr bullets over 5.2 of unique. All of my .38s and my .357 love this load accuracy wise. Unfortunately my one fixed sighted gun shoots 5" high at 25 yards with it.

I had been thinking about opening up the rear sight channel for a while now. I typically like a little more light on either side of the front sight.

Would it be practical do take a little metal off the top strap while opening it up?

The 130 grain Winchester Rangers shoot a couple inches high too. 2-3" iirc which is just fine imo but if I could drop it to be a perfect poa/poi with the rangers and 2-3" high with the heavier bullets I would be happy.

Worth it?

[41magfan]

Before you contemplate doing anything permanent with a file, I would suggest that you find a gunsmith or S&W Armorer that can "adjust" your barrel with one of these.

[03RN]

What is it?

[SAWBONES]

What is it?

Them are babbitts, hey.

One who knows how to do it, can use a flat sided babbitt to whack the barrel with it to produce a slight change in POI in the direction of the whack.

[03RN]

So kinda in the middle. If you strike it from the top the poi goes up?

Interesting.

I took a tour of the Savage factory as a kid (my dad designed their ventilation system) and watched a guy looking through a barrel in a type of clamp tapping where needed.

Same concept?

[SAWBONES]

So kinda in the middle. If you strike it from the top the poi goes up?

No, if you strike the barrel from the top (a downward strike, IOW), the POI goes down.

[03RN]

Gotcha

[41magfan]

By striking the barrel with those impact tools, you're simply moving the location of the barrel relative to its position in the frame. Five inches @ 25 yards is a fair amount but it should be doable. Thinner barrels are easier to manipulate than heavier ones and longer barrels yield better than shorter ones.

When adjusting the relative position of the rear sight - you move the sight in the direction you want POI. When adjusting the relative position of the front sight (or barrel in your case) - you move it in the opposite direction you want POI.

In your case, moving the barrel UP, makes the relative position of the front sight LOWER than it was previously.

[Alpha Sierra]

moving the barrel UP, makes the relative position of the front sight LOWER than it was previously.

I've had fullbore and smallbore target rifles with height-adjustable front sight for years so I know how this works very well. Bending the barrel alone won't fix his problem.

If you bend the barrel upwards the POI will go up higher than where it is now. There is no doubt about that.

Yes, the front sight will appear now higher in the rear sight notch but the relationship between the top of the front sight and the barrel centerline is still the same. When the shooter aims down to bring the top of the front sight even with the top of the rear sight, POI will go back down to where it originally was (meaning 5" high at 25 yards).

What needs to change is the height of one of the two sights relative to the bore's centerline.

I'm pretty sure the smacking the barrel thing is done only where there's a gross deviation from POI to POA that sight adjustments alone won't fix and done in concert with sight height modifications.

[Alpha Sierra]

03RN, I'd plug in your numbers in here and think about what to do next: http://www.sdmfabricating.com/sightcalc.html