Haven't done much precision shooting with open sights until recently. I bought an m1a and I'm getting 2.2" 5 shot groups at 100. With my ar15 I'm getting 1.6". Probably about my limit given ability and vision. Any idea what these rifles may be capable of with optics. I know it's hard to judge just curious what you guys typically see. I'm sure there are some who can shoot equally well with both. Also any recommendations for target, I'm using 100 yard small bore and it's a bit tough to see the black.
Open sights vs optics
- Thread starter 1stmar
- Start date
Art Eatman
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I had a late 1990s Bushmaster Match Target AR with a Tasco World Class 6x24x40 on it. At the bench, it was reliably 1/2 MOA. My present Colt AR with irons will do one MOA if I do my part. With a CMMG upper and a K-4, the same.
My weld-up Garand, glass-bedded and with match sights, would do 1.5" groups with Czech GI-type ammo. Darned sure wasn't easy, though. Drove me nuts trying to be consistently "nearly perfect" for sight picture.
Shooting's a lot easier since my cataract surgery.
Between decades of messing with rifles and a good number of years reading folks' comments about shooting, I'm coming to the opinion that it's less about the rifle than it is about the shooter's consistency in how a rifle is held and how consistently nearly-perfect is the sight picture when the trigger is pressed.
My weld-up Garand, glass-bedded and with match sights, would do 1.5" groups with Czech GI-type ammo. Darned sure wasn't easy, though. Drove me nuts trying to be consistently "nearly perfect" for sight picture.
Shooting's a lot easier since my cataract surgery.
Between decades of messing with rifles and a good number of years reading folks' comments about shooting, I'm coming to the opinion that it's less about the rifle than it is about the shooter's consistency in how a rifle is held and how consistently nearly-perfect is the sight picture when the trigger is pressed.
Open sights typically refer to those whose rear sights' are in front of the action on the barrel that have a V or U notch in them to align the front sight's top in. Aperture sights are rear sights with a round ring, or "aperture" to aim through centering the front sight in it. M1, M14, M16 and M1A rifles have an aperture rear sight.
Aperture sights can be used to point rifles on bullseye targets about 96% as precisely as scope sights. Providing one's aiming eye is good and if needed, a corrective lens is used, that is. One holds the rifle just as still (or wiggly) with either type.
Best accuracy on bullseye targets with such sights happens when the aiming eye's focused on the front sight; that's what appears to be moving around. It's OK if the target bullseye is a bit fuzzy and out of perfect focus. It's easier to put the front sight on target more repeatably when it's in sharper focus than the target's bullseye.
I ran a test some years ago with a target simulator in the muzzle of a Garand, then had several people aim through its rear sight adjusting it to get a perfect "sight picture" with the black "bullseye" 2 inches in front of the front sight aligned as good as possible with the front sight. The sight picture was a black ball sitting atop a black post. All of them had less than a 1/4 MOA average spread across their sight settings.
More interesting was the reason I did that test. It was a long time belief that different people look through metallic sights differently and that was the reason why each person used different sight settings for a zero at a given range with the same rifle and ammo. In that test, there was virtually no change between sight settings for each persons' perfect sight picture. The sight adjustmemts were 1/4 MOA clicks on the modified M1 rear sight. If 1/8 MOA clicks were used, the data points would have been more precise, but such is life.
Aperture sights can be used to point rifles on bullseye targets about 96% as precisely as scope sights. Providing one's aiming eye is good and if needed, a corrective lens is used, that is. One holds the rifle just as still (or wiggly) with either type.
Best accuracy on bullseye targets with such sights happens when the aiming eye's focused on the front sight; that's what appears to be moving around. It's OK if the target bullseye is a bit fuzzy and out of perfect focus. It's easier to put the front sight on target more repeatably when it's in sharper focus than the target's bullseye.
I ran a test some years ago with a target simulator in the muzzle of a Garand, then had several people aim through its rear sight adjusting it to get a perfect "sight picture" with the black "bullseye" 2 inches in front of the front sight aligned as good as possible with the front sight. The sight picture was a black ball sitting atop a black post. All of them had less than a 1/4 MOA average spread across their sight settings.
More interesting was the reason I did that test. It was a long time belief that different people look through metallic sights differently and that was the reason why each person used different sight settings for a zero at a given range with the same rifle and ammo. In that test, there was virtually no change between sight settings for each persons' perfect sight picture. The sight adjustmemts were 1/4 MOA clicks on the modified M1 rear sight. If 1/8 MOA clicks were used, the data points would have been more precise, but such is life.
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Thanks for the correction on the sight terminology. Obviously using aperture sights. I'm enjoying using the sights and have been pleasantly surprised so far. I may put some optics on just to see what the capabilities are but I think I'll stick with what I have.
96% is impressive, not sure I'm up to that. The bull size is just under 6" I believe, 8" wod be easier to ensure I am picking the same aiming point. It's tough to see if I am covering part of the bull or resting below it. I'm a long time pistol shooter and focusing on the front sight is natural for me.
96% is impressive, not sure I'm up to that. The bull size is just under 6" I believe, 8" wod be easier to ensure I am picking the same aiming point. It's tough to see if I am covering part of the bull or resting below it. I'm a long time pistol shooter and focusing on the front sight is natural for me.
1stmar, if you get a standard 100-yard smallbore target, it has an 8" bullseye; that's 4 MOA subtention. And a lot easier to see than a 6" one.
On your M1A's rear sight, it probably has the standard service aperture of about .070". A smaller aperature would make both the front sight and bullseye appear larger and look like they're better focused. National Match sights had either a .0595" or .0520" diameter aperature. And some were modified to have even smaller ones. While the smaller the aperture is, the darker the image seen through it is but most folks can handle one as small as .0450" even on cloudy days.
One method used by some service rifle competitors on their M1 and M14/M1A standard service rear sights was as follows. Clean the rear sight aperture good with naptha or alcohol, let it dry, then pack Devcon plastic steel in it from the front. After it's set, smooth of the front and back surfaces even with the aperture front and back surfaces. Then use a countersink to deepen and bevel the front of it back to where the countersink tip just starts through the back surface. Use a .040" drill bit to carefully drill a hole that size from the front; to all the way through. Use a q-tip to remove any fuzzy stuff around the hole. Finally, color it black on both sides with a Magic Marker.
Go outside and check it out for visibility on the target. If it's too dark, redrill the hole out to .0450" and try again. You'll probably like what you see and notice that it's a lot easier to get precise alignment with the front sight on the target.
Use a 6-o'clock hold; set the black bullseye so it appears sitting atop the post and appears to just touch it. This gives the best vertical repeatability as well as windage.
On your M1A's rear sight, it probably has the standard service aperture of about .070". A smaller aperature would make both the front sight and bullseye appear larger and look like they're better focused. National Match sights had either a .0595" or .0520" diameter aperature. And some were modified to have even smaller ones. While the smaller the aperture is, the darker the image seen through it is but most folks can handle one as small as .0450" even on cloudy days.
One method used by some service rifle competitors on their M1 and M14/M1A standard service rear sights was as follows. Clean the rear sight aperture good with naptha or alcohol, let it dry, then pack Devcon plastic steel in it from the front. After it's set, smooth of the front and back surfaces even with the aperture front and back surfaces. Then use a countersink to deepen and bevel the front of it back to where the countersink tip just starts through the back surface. Use a .040" drill bit to carefully drill a hole that size from the front; to all the way through. Use a q-tip to remove any fuzzy stuff around the hole. Finally, color it black on both sides with a Magic Marker.
Go outside and check it out for visibility on the target. If it's too dark, redrill the hole out to .0450" and try again. You'll probably like what you see and notice that it's a lot easier to get precise alignment with the front sight on the target.
Use a 6-o'clock hold; set the black bullseye so it appears sitting atop the post and appears to just touch it. This gives the best vertical repeatability as well as windage.
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Thanks Bart. Is the front sight usually kept the same width or is it thinned ?
I narrowed my Garand front sights to appear the same width as the NRA high power target 600 yard bullseyes 6.0 MOA subtension. At a 32 some odd inches away from my aiming eye, they had to be about .055" wide. I filed them down to that width. A tiny bit smaller than 200 and 300 yard bullseyes and a tiny bit bigger than 800 to 1000 yard ones, but seemed to be a good compromise. For an 8" bullseye at 100 yards, a .060" wide front sight on an M1A would be about right for me.
So the front to the rear of the inside of the aperature looks like a cone, right? I guess it's not real important whether the hole is exactly the center of where the opening used to be since that can be adjusted out.
Funny, I have seen the rear of many aperature sights look that way. Sometimes they look like a series of decreasing diameter circles. Not sure why that was done.
Why do you think that is. Not doubting you at all, just wonder if there is some principle behind that?
Lou
Louca, the reason the front of the aperture's coned back is to get the hole's edge as short as possible. If a perfect knife-edge between the front and back parts could be attained, it would be just like adjustable iris rear sights with a diaphragm exactly like a camera lens has. Very thin metal around that hole the light goes through.
With smaller aperture diameter, you see both front sight and target appearing sharper; more defined edges. That's why it's easier to align them with each other more precisely. It's exactly the same as a camera lens stopped down to a smaller aperture; depth of field increases and objects beyond and closer to the point of focus appear sharper.
With smaller aperture diameter, you see both front sight and target appearing sharper; more defined edges. That's why it's easier to align them with each other more precisely. It's exactly the same as a camera lens stopped down to a smaller aperture; depth of field increases and objects beyond and closer to the point of focus appear sharper.