Regulation of Fixed Sights.

[TN RAT]

I have read a great deal about the regulation of double rifles, and how they must be accurate for each barrel out to a certain distance. This is achieved by somone/an engineer calculating where the sights need to be in regards to measurements, and then the company has to spend some time sighting the thing in and getting it right.

In regards to Smith revolver fixed sights I was wondering how the process would work?

1. An engineer calculates that the front sight and rear notch need to be X height and width to regulate the gun for 158 grain bullets at X distance.

What are the weights a 38, 357, and 44 would be regulated for?

Would that include any bullets in that weight no matter what makeup?

2. Is the company or has the company ever worked on sighting in these revolvers before they were shipped out?

I wonder if double rifles would require so much more time and effort since you are essentially lining up two guns on one set of sights that is offset to one side or the other.

IOW, the production of a single barrel with the sights sitting directly on top and such a short distance apart, relatively speaking, could be fairly accurate from the drawing board to the final product.

Any thoughts?

Thanks.

 

[TN RAT]

I have read a great deal about the regulation of double rifles, and how they must be accurate for each barrel out to a certain distance. This is achieved by somone/an engineer calculating where the sights need to be in regards to measurements, and then the company has to spend some time sighting the thing in and getting it right.

In regards to Smith revolver fixed sights I was wondering how the process would work?

1. An engineer calculates that the front sight and rear notch need to be X height and width to regulate the gun for 158 grain bullets at X distance.

What are the weights a 38, 357, and 44 would be regulated for?

Would that include any bullets in that weight no matter what makeup?

2. Is the company or has the company ever worked on sighting in these revolvers before they were shipped out?

I wonder if double rifles would require so much more time and effort since you are essentially lining up two guns on one set of sights that is offset to one side or the other.

IOW, the production of a single barrel with the sights sitting directly on top and such a short distance apart, relatively speaking, could be fairly accurate from the drawing board to the final product.

Any thoughts?

Thanks.

 

[WR Moore]

As you noted, regulating double rifles is an art form, done by trial and error for one specific ammunition brand, load and range. You're not working the sights, you're regulating the barrels to hit where the sights point. There's a calculated theoretical point of convergence, getting the bullets to hit there is black art.

Initial development work on specific pistols determined the correct relationship of barrel length/sight height for the most commonly used ammunition types, largely by trial and error. In days of old, 158 grain in .38/.357 and 240 gr. in .44. Shape/type of the bullet makes no difference at the ranges most handguns are used.

Note: it used to be common practice to leave the front sights on snubbies high, to be filed down if desired by the users. High front sights are easily corrected in the field with a file. 50 feet/25 yards was the general range for zero, in many cases allowing a 6 o'clock hold on the offical bullseye targets of the time.

Once you have the initial specs, math can produce correction factors for given ranges.

Agencies placing large orders and knowing the issue ammunition can, if necessary, specify the sight settings. We used to issue 681s and the sights were set for Federal 125 gr JHP Magnums. The factory test firing should catch/correct windage errors, but might not.

 

[TN RAT]

Thanks for your informative response.

 

[haggis]

Pre-war fixed sight guns were often regulated by hand, using a lead hammer, if initial accuracy testing was not acceptable. It's not a process for the faint of heart - like sausages and laws, you don't really want to watch when it was going on.

Buck

 

[shawn mccarver]

Originally posted by haggis:
Pre-war fixed sight guns were often regulated by hand, using a lead hammer, if initial accuracy testing was not acceptable. It's not a process for the faint of heart - like sausages and laws, you don't really want to watch when it was going on.

Buck

The FBI Model 13 3 inch guns had fixed sights, but the front sights were actually adjustable and removable. The armorers at Quantico would replace the front sights and the pins holding them in were polished over in such a way as to be almost invisible. They had different heights for elevation adjustment and some that were just barely offset for windage issues. It only takes thousandths of an inch to make a dramatic difference at 25 and 50 yards. The FBI had a qualification course in those days that had a 60 yard stage.