norc m14 shorty sights
- Thread starter Dop_J
- Start date
No worries man 
it stumps most guys at first and I've scratched my own head over the issue more times than one hehehehe
If you put it on paper, it goes like this.
Draw a straight line representing the bore center of a 22" barrel. The line must be the length of the distance between rear sight aperture and front sight blade at it's highest point.
Next take the height of the center of the bottomed out rear aperture and make a mark.
Now go to front sight location, measure up from the line, the distance from bore center to top of standard sight blade.
Connect the two marks with a straight line.
This will show you why a higher sight is needed as the two lines before you will not be parallel. The top (sight) line angles down, towards the bore. So as you move the sight back, the blade height must increase to compensate.
This is magnified when shortening the barrel as you now must also account for the change in tragectory that 3 1/2 less inches of barrel gives the .308 cartridge. Again, an increase in blade height in necessary.
it stumps most guys at first and I've scratched my own head over the issue more times than one heheheheIf you put it on paper, it goes like this.
Draw a straight line representing the bore center of a 22" barrel. The line must be the length of the distance between rear sight aperture and front sight blade at it's highest point.
Next take the height of the center of the bottomed out rear aperture and make a mark.
Now go to front sight location, measure up from the line, the distance from bore center to top of standard sight blade.
Connect the two marks with a straight line.
This will show you why a higher sight is needed as the two lines before you will not be parallel. The top (sight) line angles down, towards the bore. So as you move the sight back, the blade height must increase to compensate.
This is magnified when shortening the barrel as you now must also account for the change in tragectory that 3 1/2 less inches of barrel gives the .308 cartridge. Again, an increase in blade height in necessary.
Mauser GDog
CGN frequent flyer
Not quite
Smith enterprise makes 2 versions of their gas lock sights, one for 22" barrels and a higher one for 18" barrels. With a higher sight base that is.
Do those Smith sights fit the chinese barrel threads? I was told they don't.
They do not.
I mentioned as an example only.
The was a canadian company, 'Volters' I believe that made a bunch of gas locks but they disappeared.
Due to inconsistancies in chinese quality control, installing a gas lock sight with chinese barrel and gas system can be frustrating.
Reason 1) even with barrel correctly indexed, many gas locks with sit canted to one side.
This is because of slightly 'off' gas cylinder splines. This causes a problem as the cylinder and gas plug dictate final gas lock position.
A Gas lock sight on a chinese rifle is something I gave up on a LONG time ago.
I mentioned as an example only.
The was a canadian company, 'Volters' I believe that made a bunch of gas locks but they disappeared.
Due to inconsistancies in chinese quality control, installing a gas lock sight with chinese barrel and gas system can be frustrating.
Reason 1) even with barrel correctly indexed, many gas locks with sit canted to one side.
This is because of slightly 'off' gas cylinder splines. This causes a problem as the cylinder and gas plug dictate final gas lock position.
A Gas lock sight on a chinese rifle is something I gave up on a LONG time ago.
They do not.
Due to inconsistancies in chinese quality control, installing a gas lock sight with chinese barrel and gas system can be frustrating.
Reason 1) even with barrel correctly indexed, many gas locks with sit canted to one side.
This is because of slightly 'off' gas cylinder splines. This causes a problem as the cylinder and gas plug dictate final gas lock position.
A Gas lock sight on a chinese rifle is something I gave up on a LONG time ago.
My sight on top of the gas lock is ever so slightly canted to one side but it's not only the gas lock splines that are "off". Splines on muzzle end are "off" too and even more so. So, do I leave the sight on the gas system (lesser of two evils) and get used to compensating when aiming or is there another remedy? Note: the barrel has not be checked for indexing. Do that first?
When I've done installs using all american made parts, the procedure goes like this.
Prep and install barrel to index, gas port 180degrees from top dead center.
Install gas system and ensure it fits tight in it's splineways. Ie: no rotational play
Then install gas lock sight and gas plug, then verify "index" with rear sight.
So using a dovetailed gas lock sight allows you to check level between receiver at the rear sight and the gas locks dovetail.
IF the gas lock sight is "out of index" but the barrel is indexed to the gas port.... One can compenstate by adjusting barrel index to comply with gas lock index. BUT within 3 degrees either way from top dead center. More adustment than that and thing start to go wrong.
Gas lock front sights where all the rage in 2007 but sadly a lot of folks realized, they work and fit inconsistantly on the chinese product.
On a US made barrel/gas system, I wouldn't hesitate to use one
Prep and install barrel to index, gas port 180degrees from top dead center.
Install gas system and ensure it fits tight in it's splineways. Ie: no rotational play
Then install gas lock sight and gas plug, then verify "index" with rear sight.
So using a dovetailed gas lock sight allows you to check level between receiver at the rear sight and the gas locks dovetail.
IF the gas lock sight is "out of index" but the barrel is indexed to the gas port.... One can compenstate by adjusting barrel index to comply with gas lock index. BUT within 3 degrees either way from top dead center. More adustment than that and thing start to go wrong.
Gas lock front sights where all the rage in 2007 but sadly a lot of folks realized, they work and fit inconsistantly on the chinese product.
On a US made barrel/gas system, I wouldn't hesitate to use one
