2 replica peacemakers both shoot 2.5 inches left at 25v yards - Why?

[hawg]

Have you ever tried it?

 

[JimGnitecki]

My 60+ years tells me otherwise also. I do better with all my pinkies on the grip.

We're still talking about handgun grips, right?

Jim G

 

[JimGnitecki]

I found some very useful information tonight relevant to this windage issue, by accident.

I had recently accidentally got a bag of 357 SUPER Magnum cases from a friend, who thought they were 357 Magnum cases. Although the cases ARE marked as being "super", my fiend and I both missed that as the marking on the base of the case has "357 Magnum" separated from "Super" . The 357 SUPER Magnum cases are ALMOST identical to 357 Magnum cases but apparently have thicker walls. I went Googling looking for more informaiton on the 357 Super Magnum caliber, as I plan to resell the 357 Super Magnum cases as I have no firearm in that caliber.

On one Dan Wesson forum, I found a 2-year old posting posting in which the poster described his testing at different amounts of popwder and different powders. What struck me in his report was that different amounts of powder, OR different powders, each produced notable changes in POI and grouping at the POI, in BOTH windage and elevation. The elevation changes of course are no surprise given the differing velocities produced, but the windage changes were striking in their magnitude, moving the POI in both directions - left and right - depending on the powder and number of grains.

Now I have no way of knowing whether the POI changes in windage were a result of the LOADS themsleves, or whether they were the result of the shooter's grip on the firearm being affected by the changes in recoil.

Nevertheless, that shooter's experience suggests that regardless of what specifically caused the POI changes, the net results WERE chnages in POI as the loads changed.

That give me hope that I might be able to find a load that moves the POI closer to the POA.

Jim G

 

[Barbaroja]

I feel like your chasing your tail. Learn to shoot the single actions properly. There doesn’t sound like there is anything wrong with the guns but with your trigger pull.
You keep looking for other reasons why they are shooting left. You know why they are shooting left. You could try and spend time and money to modify the guns or you could practice your technique more. Which would be my suggestion.

 

[doubleh]

We're still talking about handgun grips, right?

Jim G

Of course. We aren't on that sniper website where about anything goes.

 

[JimGnitecki]

Figured out the windage problem: It's the sights on the 2 revolvers!



My laser boresighter arrived today:



This one has all the right features for accuracy, including 12 bore inserts, each of which is screwdriver-adjustable for a perfect fit.

Our home is what is called a "backsplit" with a very long garage right at the front under the bedrooms, so even after allowing a generous distance for myself to get a comfortable "shooting" position behind an unpholstered chair, I was able to set up a "range" for the boresighter of 47 feet.

I used the same paper target as I had used for the actual range session:



I aligned the sights as perfectly as I could with the vertical centreline of the target. Since the boresighter is coaxial with the BORE, not the sights, I had to RAISE the front sight high enough to see the red laser dot. But I kept the sights aligned with that vertical centreline.

I tested both revolvers multiple times and got consistent results, time and again, for each.

On the "better" revolver (the one with less leftward POI versus POA), The laser beam lit up the target on a vertical line that was approximately on the left tip of that small triangle. That tip is 1.44" left of the centerline of the target. The shooting distance was 47 feet, so at 25 yards = 75 feet, the POI versus POA would be 1.6 x 1.44" = 2.3". This matches very closely what that revolver delivered at an earlier session using Trail Boss powder. (I did not pack or fire this revolver at this latest session).

On the "worse" revolver (the one i fired at this last range session, the laser dot was vertically aligned with the point where the horizontal target line meets the inside of the black ring. That is 2.78" left of the centerline of the target. Extrapolating that 2.78" from 47 feet to 75 feet, I get 4.4". This is pretty close to the 4" I consistently estimated for all the groups fired at the actual range session using this revolver.

So, yes, BOTH revolvers have front sights that are misaligned with the bore.

Now I know that both revolvers also shoot low versus POA, but that is easily corrected via filing down and reblueing the front sight, once I have firmly decided that I have a handload that I am willing to live with.

The error on the "better" revolver is 2.3" at 25 yards (900 inches). I just measured the sight radius on the revolvers, and it is about 5.75". So, the "better" revolver requires a front sight movement of 2.3 / 900 x 5.75 = .015 inches to the left. OR, I need to add .015" x 2 = .03 inches to the left side of the front sight. OR, I need to widen the rear sight V by .03 inches on its RIGHT side.

The error on the "worse" revolver is 4.4" at 25 yards (900 inches). So the worse revolver requires a front sight movement of 4.4 / 900 x 5.75 = .028" to the left. OR, I need to add .028" x 2 = .056 inches to the left side of the front sight. OR, I nee to widen the rear sight V by .056 inches on its RIGHT side.

I'm very glad I found out WHY I have been shooting left so consistently. Given all the above, apparenrtly I am a pretty good shooter. I just need to correct those built-in errors in the sights.

Jim G

 

[Tallball]

I apologize for doubting your technique and I'm glad you found the problem.

 

[JimGnitecki]

I apologize for doubting your technique and I'm glad you found the problem.

No apology needed! I appreciate ALL the observations and suggestions made. You never know which one made will be the one that "triggers" the solution. In this case, someone at the SASS Wire (the forum dedicated to Cowboy Action Shooting) suggested testing with a boresighter, which made perfect sense as a way of either finding the sights are the issue OR eliminating them as a "suspect".

I was pleasantly surprised at how little a reasonably high quality laser boresighter costs on Amazon, and was impressed at its consistent visible reproducability of the problem. I tried each revolver several times, deliberately rotating the boresighter each time to find any non-concentricity in it if it existed, which it did not.

The cost benefit ratio of that boresighter in this case is fantastic, as it stops me from having to chase some nebulous grip issue that I would be doomed to never find since it does not exist in my case, even though it is probably the legitimate cause for other shooters of Peacemaker replicas.

I am SO glad you and other shooters took the time to read my story and help me out. The help led to the correct diagnosis, and now I know how I can fix the problem if a handload change does not do so.

Jim G

 

[Jim Watson]

So the worse revolver requires a front sight movement of 4.4 / 900 x 5.75 = .028" to the left. OR, I need to add .028" x 2 = .056 inches to the left side of the front sight. OR, I nee to widen the rear sight V by .056 inches on its RIGHT side.

I don't know about adding to a sight blade.
Otherwise, not "OR", both. Which is what I had done, that way part of the adjustment is made on each sight, the change is less obvious.
As I said above, my rear sight was milled square from the old style V notch with a bias to the right AND the barrel was torqued to the left. Even so, the front sight is visibly out of plumb, but it shoots where it looks.
I read an article by one gunsmith who did not turn the barrel, he bent it! The curvature to correct the aim was imperceptible on a 7.5" cavalry model but he said it would show on a 3" sheriff's model. (My crooked ASM Schofield was not apparent except by looking at the target or a range rod.)

There is another solution. I saw a well worn SAA in the town museum of Hawthorne Nevada that had a rifle type ivory bead front sight dovetailed into the barrel. It looked a little funny but it sure gave that frontiersman a bold and adjustable sight picture.
I followed suit; when I converted a 1851 Navy reproduction to cartridge, the brass cone front sight did not work, not well aligned, not a reproducible sight picture. So FLG dovetailed the barrel and pushed in a plain black post, aligned for windage, the right height for elevation.
I will take a picture, no 30.

 

[JimGnitecki]

I don't know about adding to a sight blade.
Otherwise, not "OR", both. Which is what I had done, that way part of the adjustment is made on each sight, the change is less obvious.
As I said above, my rear sight was milled square from the old style V notch with a bias to the right AND the barrel was torqued to the left. Even so, the front sight is visibly out of plumb, but it shoots where it looks.
I read an article by one gunsmith who did not turn the barrel, he bent it! The curvature to correct the aim was imperceptible on a 7.5" cavalry model but he said it would show on a 3" sheriff's model. (My crooked ASM Schofield was not apparent except by looking at the target or a range rod.)

There is another solution. I saw a well worn SAA in the town museum of Hawthorne Nevada that had a rifle type ivory bead front sight dovetailed into the barrel. It looked a little funny but it sure gave that frontiersman a bold and adjustable sight picture.
I followed suit; when I converted a 1851 Navy reproduction to cartridge, the brass cone front sight did not work, not well aligned, not a reproducible sight picture. So FLG dovetailed the barrel and pushed in a plain black post, aligned for windage, the right height for elevation.
I will take a picture, no 30.

Yes, I can see how there can be multiple approaches to solving the problem. Someone the other day pointed out to me that Brownell will apparently make a custom piece on request that is made a specific thickness to your spec and that matches your front sight's factory profile as seen from left or right, to silver solder onto the side of your front sight. For me, being in Canada versus U.S., that sounds a little costly and would take a long time just in shipping "internationally", but still, if true, it IS one option.

My actual ladder testing at the range 2 days ago, using a different bullet and different powder at different numbers of grains, also showed that the specific handload DOES change the windage of POI versus POA. My one revolver whose POI was a bit over 3 inches left, consistently, with all the Trail Boss loads went to 4 inches left, consistently, with TiteGroup.

I am learning a lot right now about POI versus POA!

Jim G

 

[Jim Watson]

Anecdote Alert:

I traded a European automatic for a Colt SA .44 Special, 7.5" barrel. I bought a .44-40 cylinder for common ammo with my Winchester.
I was fortunate, it shot both rounds to the same POI. But I wanted to be Kewl, so I had a 4.75" "gunslinger" barrel fitted. But then the two loads did not shoot to the same POI and my hold was less steady to boot. So I had the 7.5" put back on.
Somewhere in there, I bought a Cimarron/ASM .44-40 to comprise a "set" for Cowboy Action Shooting. That is the one that required sight correction.

 

[Jim Watson]

OK, here is that dovetailed 1851 front sight. It will be more obvious on a round barrel but it gives almost unlimited options for adjustment and sight picture.

 

[JimGnitecki]

OK, here is that dovetailed 1851 front sight. It will be more obvious on a round barrel but it gives almost unlimited options for adjustment and sight picture.

View attachment 1140135

Thanks for posting that photo. That solution might also be less costly, as it is more of a "standard" job for a gunsmith. Snd it is easily changeable if I ever change a handload. I am warming up to this solution.

Jim G