THE ACCURATERELOADING.COM GUNSMITHING FORUM


Moderators: jeffeosso
Go
New
Find
Notify
Tools
Reply
  
Express Sight Question
 Login/Join
 
One of Us
posted
When setting up express sights on a rifle, should the top of the front and top of the rear be the same height over the CL of the bore?

Trying to get close to start so that I won't have to do a ton of filing later.
 
Posts: 43 | Registered: 07 January 2017Reply With Quote
One of Us
posted Hide Post
Think about this; the bullet starts to drop as soon as it leaves the bore if the gun is level.


Jim Kobe
10841 Oxborough Ave So
Bloomington MN 55437
952.884.6031
Professional member American Custom Gunmakers Guild

 
Posts: 5533 | Location: Minnesota | Registered: 10 July 2002Reply With Quote
One of Us
Picture of Mike_Dettorre
posted Hide Post
The top of the front sight will always be lower than the top of the rear sight because the barrel will always need to be angled upward slightly to compensate for the drop of the bullet which begins immediately upon leaving the muzzle because of gravity.

Your question though is related to getting close so you don't have to "do a ton of filing"

The short practical answer is you can start with them level.

Given that most rifles have a distance between the front and rear sight of around 15 inches and a moderate velocity round with a moderate BC fired level will drop about 1.5 inches at 100 yards, the required sight adjustment is .006. Meaning if you started with them level you would be filing 6/1000.

Even if you had a really slow cartridge 2200 fps and really bad BC .186 you would only have ~3 inches of drop at 100 yards and if you had a short sight radius of 12 inches, you would need to file about 12/1000.

Only you can decide what a lot filing is.

If your desired range for the sights is 50 yards than all of those filing amounts are doubled.

If you provide the caliber, projectile weight and type as well as the velocity and the desired sight in range, I can give you a much closer calculation.


Mike

Legistine actu quod scripsi?

Never under estimate the internet community's ability to reply to your post with their personal rant about their tangentially related, single occurrence issue.




What I have learned on AR, since 2001:
1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken.
2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps.
3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges.
4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down.
5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine.
6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle.
7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions.
8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA.
9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not.
10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact.
11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores.
12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence.
13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances.
 
Posts: 10169 | Location: Loving retirement in Boise, ID | Registered: 16 December 2003Reply With Quote
One of Us
posted Hide Post
The gun is a 35 Whelen AI, firing a 310 Woodleigh at 2300 FPS. If the top of the bead is flush with the top of the unfiled express sight, I think I would have quite a bit of material to work with during sight in.
 
Posts: 43 | Registered: 07 January 2017Reply With Quote
One of Us
Picture of Mike_Dettorre
posted Hide Post
what is your desired zero range? what is the distance between the sights?


Mike

Legistine actu quod scripsi?

Never under estimate the internet community's ability to reply to your post with their personal rant about their tangentially related, single occurrence issue.




What I have learned on AR, since 2001:
1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken.
2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps.
3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges.
4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down.
5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine.
6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle.
7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions.
8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA.
9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not.
10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact.
11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores.
12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence.
13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances.
 
Posts: 10169 | Location: Loving retirement in Boise, ID | Registered: 16 December 2003Reply With Quote
One of Us
posted Hide Post
17" and a 100 yd zero (0.50" high at 50 roughly).
 
Posts: 43 | Registered: 07 January 2017Reply With Quote
One of Us
Picture of Mike_Dettorre
posted Hide Post
A 310 woodleigh at 2300 fps fired level drops about .8 inches at 50 and 3.4 at 100.

Therefore, correcting for the 3.4 inches requires 16/1000 of sight movement with a 17 inch sight radius. So if you start with them even you will have plenty to work with.

As a test of practicality, you might want to put some 3 inch black dots out at 100 yards and see what your eyes ability is to discern a target. My point is if you can only discern that size target at 100 yards. if you can discern no less than 3" you may want to be sighted in at 1.5 high at 100.


Mike

Legistine actu quod scripsi?

Never under estimate the internet community's ability to reply to your post with their personal rant about their tangentially related, single occurrence issue.




What I have learned on AR, since 2001:
1. The proper answer to: Where is the best place in town to get a steak dinner? is…You should go to Mel's Diner and get the fried chicken.
2. Big game animals can tell the difference between .015 of an inch in diameter, 15 grains of bullet weight, and 150 fps.
3. There is a difference in the performance of two identical projectiles launched at the same velocity if they came from different cartridges.
4. While a double rifle is the perfect DGR, every 375HH bolt gun needs to be modified to carry at least 5 down.
5. While a floor plate and detachable box magazine both use a mechanical latch, only the floor plate latch is reliable. Disregard the fact that every modern military rifle uses a detachable box magazine.
6. The Remington 700 is unreliable regardless of the fact it is the basis of the USMC M40 sniper rifle for 40+ years with no changes to the receiver or extractor and is the choice of more military and law enforcement sniper units than any other rifle.
7. PF actions are not suitable for a DGR and it is irrelevant that the M1, M14, M16, & AK47 which were designed for hunting men that can shoot back are all PF actions.
8. 95 deg F in Africa is different than 95 deg F in TX or CA and that is why you must worry about ammunition temperature in Africa (even though most safaris take place in winter) but not in TX or in CA.
9. The size of a ding in a gun's finish doesn't matter, what matters is whether it’s a safe ding or not.
10. 1 in a row is a trend, 2 in a row is statistically significant, and 3 in a row is an irrefutable fact.
11. Never buy a WSM or RCM cartridge for a safari rifle or your go to rifle in the USA because if they lose your ammo you can't find replacement ammo but don't worry 280 Rem, 338-06, 35 Whelen, and all Weatherby cartridges abound in Africa and back country stores.
12. A well hit animal can run 75 yds. in the open and suddenly drop with no initial blood trail, but the one I shot from 200 yds. away that ran 10 yds. and disappeared into a thicket and was not found was lost because the bullet penciled thru. I am 100% certain of this even though I have no physical evidence.
13. A 300 Win Mag is a 500 yard elk cartridge but a 308 Win is not a 300 yard elk cartridge even though the same bullet is travelling at the same velocity at those respective distances.
 
Posts: 10169 | Location: Loving retirement in Boise, ID | Registered: 16 December 2003Reply With Quote
One of Us
posted Hide Post
Thanks Mike.
 
Posts: 43 | Registered: 07 January 2017Reply With Quote
One of Us
Picture of sambarman338
posted Hide Post
Another issue with express sights is does the back sight have flats each side of the V or is it one with a giant V angling out to the full width of the leaf (originally needed when a swing-up moon sight was also provided).

If you have flats, you can line up the top of your front sight with them when shooting, if not your bead would need to be held deep in the V. Only filing in the V or replacing the bead with one of a different height would help with this second type. Also, unless you are going to have a moon sight, too, I'd advise a rear sight with the flats as it is easier to line up the bead with the flats than obsess with tucking it right down in the V - that might work OK with careful shots but is not so good in a hurry.
 
Posts: 5166 | Location: Melbourne, Australia | Registered: 31 March 2009Reply With Quote
One of Us
posted Hide Post
I'll be filing the V, so I can leave a flat on the sides. Thanks for the suggestion.
 
Posts: 43 | Registered: 07 January 2017Reply With Quote
One of Us
posted Hide Post
Assuming you mean something like this?

 
Posts: 43 | Registered: 07 January 2017Reply With Quote
  Powered by Social Strata  
 


Copyright December 1997-2023 Accuratereloading.com


Visit our on-line store for AR Memorabilia