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PhilOhio · 08-01-2009, 01:14 PM

...just wanted to share with you fellas the interesting and accidental fix to a problem which had been driving me up the wall.

Several months ago, I was asking forum members for help in understanding why my newly acquired 1937 S/42 was shooting about 6" to 8" high at standard 50' target distance...shooting my reloaded cartridges which closely duplicated regular service loads.

Lugers are much more accurate than that. And no, this is not because they were calibrated for 100 meters. Firing dynamics of the pistol (including muzzle jump before the bullet leaves the barrel) are such that there is little or no 100 meter drop of a 125 grain 9mm bullet travelling at 1100 feet per second; most assuredly not 6".

Since drifting in a replacement front sight blade is something which can be done without permanently changing a good matching pistol, it seemed like a reasonable thing to try. Yesterday was the day, thanks to my Chinese bench top mini mill.

I've made a lot of front sights to correct point of impact on fixed sight handguns. Usually I epoxy a piece of cereal box cardboard to the barrel; shoot it on the range; use a scissors to trim it until groups are zeroed at 50'; measure this correct height cardboard sight and then make/install a metal blade. This time I just made a rough squared metal blade about 1/8" higher than my guesstimate of what would be needed; and with male dovetail to match the Luger barrel's slot. I started with a blade 11/32" above the flat on the front sight boss of the barrel.

I milled the blade .077" wide, thinking this was about as thick as it could be, to be useful in matching the width of the rear sight's "V" at the top; any wider, and I could not accurately center the front sight blade. And I did not want to modify the rear toggle link by widening and squaring the notch, as should really be done for a shooter.

For you ambitious guys who try things like this, I have a 12 volt D.C. to 110 volt A.C. inverter which I plug into my car's lighter receptacle. It feeds a speed controller for my Dremel tool, on which I mount an abrasive cutoff wheel; this because there is no outdoor power at my range, 2.5 miles from home.

Anyhow...shoot a couple, trim sight slightly, shoot a couple more; sight adjustment the hard way. But it works great.

After only two or three Dremel trims, I was dead on at 50'. And I noticed it had been unusually easy to get a good sight picture, unlike before, with the Luger's standard tapered blade.

THAT, it turns out, had been most of the original problem!

Back home, I contoured the new sight to look like an original, and used a Swiss file to put in all the little anti-glare grooves; blued it and drifted it into position to center shots, which had earlier been striking slightly to the left.

Then I measured the heights of the original Mauser blade and my new one. Huh? What's this? My new blade, which totally corrected point of impact, was only 1/32" higher, being 1/4" high exactly! How could this correct a point of impact difference of 6" to 8" at only 50 feet?

It was all in the width, substituting an untapered, squared blade .077" thick...instead of the skinny Luger inverted "V".

The human eye is no different than a camera lense. It cannot keep a rear sight, front sight, and distant target all in focus at the same time. The Luger sight system, with a rear "V" and thin inverted front "V" is the worst of all worlds; at least, if you want to see and hit anything. For our collector guns, it's fine.

So almost all modern arms manufacturers use a fairly wide front sight blade on guns that are actually expected to hit something. It makes it so much easier to center the blade.

After about age 40, our eyes' ability to focus at short range begins to drop off dramatically. With the skinny Luger front sight, about the top 1/3 of it becomes virtually invisible. It did for me. All I could see was the fuzzy lower 2/3, and I guess it was the top of that fuzz which I was trying to align with the top of the rear sight blade.

This new squared blade completely changes the gun's functionality for me, and probably would do so for most of you. Do any of you Luger experts know if somebody already makes one? If not, somebody should. And they should come in about 3 - 4 different heights, for differences among pistols and loads. It seems to me that there are enough fixed sight "shooter" Lugers out there, and enough people using them, that this worthwhile mod could be offered at a modest price, considering the ease of CNC milling of such a simple part...possibly just a minor dimensional variant of a sight blade already on the market; no need to reinvent the wheel.

Question for you seasoned Luger experts and collectors: Did DWM or Mauser go to the trouble of accuracy testing new pistols and equipping them with standard front sight blades of differing heights, to regulate point of impact and correct for normal production line variations? Seems like this would be the correct German way of doing things.

By the way: I found the German front sight blade notch, on my Mauser barrel, was tapered from right to left. Or maybe it was the blade's dovetail. But measurements suggested it was the notch. You can drift in an original blade from the right, but cannot drift it further to the left (beyond center) to correct left-of-center point of impact. Strange. With aftermarket barrels, the notch seems to be straight through, so you can adjust the front blade.

And also by the way: This week, after owning it for 40 years, I've been making adjustments on my minty 1917 artillery Luger's "fine tune" sights, to zero it; having made a fancy spanner and ordered another from Tom H. I don't think the screws had been turned since leaving the factory. I am mightily, mightily impressed by the precision craftsmanship which went into these. They work. The pistol is virtually a match pistol. And it was obvious to me that special tuning had also gone into the trigger pull which, for a Luger, is amazing.

I'm learning, or re-learning, how some of you have become so deeply hooked on these fine pistols; earlier, that is.

08-01-2009, 01:14 PM	#1
PhilOhio User Join Date: Apr 2009 Location: Ohio Posts: 145 Thanks: 5 Thanked 17 Times in 14 Posts	Front Sight Mod ...just wanted to share with you fellas the interesting and accidental fix to a problem which had been driving me up the wall. Several months ago, I was asking forum members for help in understanding why my newly acquired 1937 S/42 was shooting about 6" to 8" high at standard 50' target distance...shooting my reloaded cartridges which closely duplicated regular service loads. Lugers are much more accurate than that. And no, this is not because they were calibrated for 100 meters. Firing dynamics of the pistol (including muzzle jump before the bullet leaves the barrel) are such that there is little or no 100 meter drop of a 125 grain 9mm bullet travelling at 1100 feet per second; most assuredly not 6". Since drifting in a replacement front sight blade is something which can be done without permanently changing a good matching pistol, it seemed like a reasonable thing to try. Yesterday was the day, thanks to my Chinese bench top mini mill. I've made a lot of front sights to correct point of impact on fixed sight handguns. Usually I epoxy a piece of cereal box cardboard to the barrel; shoot it on the range; use a scissors to trim it until groups are zeroed at 50'; measure this correct height cardboard sight and then make/install a metal blade. This time I just made a rough squared metal blade about 1/8" higher than my guesstimate of what would be needed; and with male dovetail to match the Luger barrel's slot. I started with a blade 11/32" above the flat on the front sight boss of the barrel. I milled the blade .077" wide, thinking this was about as thick as it could be, to be useful in matching the width of the rear sight's "V" at the top; any wider, and I could not accurately center the front sight blade. And I did not want to modify the rear toggle link by widening and squaring the notch, as should really be done for a shooter. For you ambitious guys who try things like this, I have a 12 volt D.C. to 110 volt A.C. inverter which I plug into my car's lighter receptacle. It feeds a speed controller for my Dremel tool, on which I mount an abrasive cutoff wheel; this because there is no outdoor power at my range, 2.5 miles from home. Anyhow...shoot a couple, trim sight slightly, shoot a couple more; sight adjustment the hard way. But it works great. After only two or three Dremel trims, I was dead on at 50'. And I noticed it had been unusually easy to get a good sight picture, unlike before, with the Luger's standard tapered blade. THAT, it turns out, had been most of the original problem! Back home, I contoured the new sight to look like an original, and used a Swiss file to put in all the little anti-glare grooves; blued it and drifted it into position to center shots, which had earlier been striking slightly to the left. Then I measured the heights of the original Mauser blade and my new one. Huh? What's this? My new blade, which totally corrected point of impact, was only 1/32" higher, being 1/4" high exactly! How could this correct a point of impact difference of 6" to 8" at only 50 feet? It was all in the width, substituting an untapered, squared blade .077" thick...instead of the skinny Luger inverted "V". The human eye is no different than a camera lense. It cannot keep a rear sight, front sight, and distant target all in focus at the same time. The Luger sight system, with a rear "V" and thin inverted front "V" is the worst of all worlds; at least, if you want to see and hit anything. For our collector guns, it's fine. So almost all modern arms manufacturers use a fairly wide front sight blade on guns that are actually expected to hit something. It makes it so much easier to center the blade. After about age 40, our eyes' ability to focus at short range begins to drop off dramatically. With the skinny Luger front sight, about the top 1/3 of it becomes virtually invisible. It did for me. All I could see was the fuzzy lower 2/3, and I guess it was the top of that fuzz which I was trying to align with the top of the rear sight blade. This new squared blade completely changes the gun's functionality for me, and probably would do so for most of you. Do any of you Luger experts know if somebody already makes one? If not, somebody should. And they should come in about 3 - 4 different heights, for differences among pistols and loads. It seems to me that there are enough fixed sight "shooter" Lugers out there, and enough people using them, that this worthwhile mod could be offered at a modest price, considering the ease of CNC milling of such a simple part...possibly just a minor dimensional variant of a sight blade already on the market; no need to reinvent the wheel. Question for you seasoned Luger experts and collectors: Did DWM or Mauser go to the trouble of accuracy testing new pistols and equipping them with standard front sight blades of differing heights, to regulate point of impact and correct for normal production line variations? Seems like this would be the correct German way of doing things. By the way: I found the German front sight blade notch, on my Mauser barrel, was tapered from right to left. Or maybe it was the blade's dovetail. But measurements suggested it was the notch. You can drift in an original blade from the right, but cannot drift it further to the left (beyond center) to correct left-of-center point of impact. Strange. With aftermarket barrels, the notch seems to be straight through, so you can adjust the front blade. And also by the way: This week, after owning it for 40 years, I've been making adjustments on my minty 1917 artillery Luger's "fine tune" sights, to zero it; having made a fancy spanner and ordered another from Tom H. I don't think the screws had been turned since leaving the factory. I am mightily, mightily impressed by the precision craftsmanship which went into these. They work. The pistol is virtually a match pistol. And it was obvious to me that special tuning had also gone into the trigger pull which, for a Luger, is amazing. I'm learning, or re-learning, how some of you have become so deeply hooked on these fine pistols; earlier, that is.