How much do I need to lower the rear sight on this Thompson Center Encore Pro Hunter .50 cal?

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Aim1

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I shot this at 25 yards the horizontal seemed fine but the vertical appeared very high. Moved to 50 yards and it hit above the paper. I believe the fact that the 2nd shot was a bit to the left of center was more me than the gun. I was in a hurry to shoot before work and was using a bipod.

How far do I need to lower the rear sight?


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More information will help.

What projectile and powder charge gave these results? What distance do you want for a zero? If you are planning to shoot at ranges a lot farther than 50 yards, you might not have to make any changes, since muzzleloader trajectories look like rainbows.

I assume you are presently using iron sights rather than a scope. What sights are they? What is the distance from the rear sight to the front sight? If the rear sight is already bottomed out it may be necessary to change out one or both of the sights.

If you are using a scope, which one and how high above the bore is it mounted? If the scope’s reticle adjustment is not already down as far as possible, cranking it down a bit and using trial and error saves a lot of calculations! :)
 
More information will help.

What projectile and powder charge gave these results? What distance do you want for a zero? If you are planning to shoot at ranges a lot farther than 50 yards, you might not have to make any changes, since muzzleloader trajectories look like rainbows.

I assume you are presently using iron sights rather than a scope. What sights are they? What is the distance from the rear sight to the front sight? If the rear sight is already bottomed out it may be necessary to change out one or both of the sights.

If you are using a scope, which one and how high above the bore is it mounted? If the scope’s reticle adjustment is not already down as far as possible, cranking it down a bit and using trial and error saves a lot of calculations! :)


I'm thinking my longest shot would be 100 yards. This is iron sights. Original factory sights.


Using 100 volume of Blackhorn 209 and Federal Premium Trophy Copper BOR Lock system ammo 270 grain.
 
It looks like your point of impact is about 10” high at 50 yards. With that load and no sight adjustment the point of impact should drop to about 5” high at 100 yards. So I would bring the sight down enough to move your 50 yard point of impact 5” to 8” down, to keep the point of impact within 3” of point of aim between 50 and 100 yards. Assuming a 20” sight radius which should be the length of your barrel on the Encore, the rear sight should move about 0.06” to 0.09” inches down.

Estimates are always wrong, but this should get you in the ballpark. By all means confirm the new point of impact at both 50 and 100 yards before shooting at game. Good luck!
 
It looks like your point of impact is about 10” high at 50 yards. With that load and no sight adjustment the point of impact should drop to about 5” high at 100 yards. So I would bring the sight down enough to move your 50 yard point of impact 5” to 8” down, to keep the point of impact within 3” of point of aim between 50 and 100 yards. Assuming a 20” sight radius which should be the length of your barrel on the Encore, the rear sight should move about 0.06” to 0.09” inches down.

Estimates are always wrong, but this should get you in the ballpark. By all means confirm the new point of impact at both 50 and 100 yards before shooting at game. Good luck!


Thanks!
 
Another consideration. If those two shots were fired at the same point of aim from 25 yards and from a bipod rest, you may need to do some load development. It’s only two shots and they’re separated by 3-4 inches. At 100 yards you’d be shooting at least 12” groups, probably more, and you may not have time to use the bipod.

I honestly don’t mean to preach but if that means you don’t hunt at all this year then that would be preferable to taking this outfit to the field and wounding an animal. If you don’t know within a very small margin exactly where the bullet is going to land you should not launch it against a living breathing creature. More range time, much more... End of sermon.
 
Another consideration. If those two shots were fired at the same point of aim from 25 yards and from a bipod rest, you may need to do some load development. It’s only two shots and they’re separated by 3-4 inches. At 100 yards you’d be shooting at least 12” groups, probably more, and you may not have time to use the bipod.

I honestly don’t mean to preach but if that means you don’t hunt at all this year then that would be preferable to taking this outfit to the field and wounding an animal. If you don’t know within a very small margin exactly where the bullet is going to land you should not launch it against a living breathing creature. More range time, much more... End of sermon.


Fitest shot was at 25 yards and 2and was at 50 yards.

I wanted to see high it would be at 50 to see if it might be ok for 100 yards.

Obviously still too high.
 
I shot this at 25 yards the horizontal seemed fine but the vertical appeared very high. Moved to 50 yards and it hit above the paper. I believe the fact that the 2nd shot was a bit to the left of center was more me than the gun. I was in a hurry to shoot before work and was using a bipod.

How far do I need to lower the rear sight?


here is a basic formula
Amount of Error X Sight Radius/Distance
= Sight Correction Needed
all in inchs
Example
At 100 yards, your shot is 6" low and the distance between your front and rear sight is 19.5".

6 X 19.5/3600 = .0325
 
Fitest shot was at 25 yards and 2and was at 50 yards.

I wanted to see high it would be at 50 to see if it might be ok for 100 yards.

Obviously still too high.
Yes. Still. How confident are you in the accuracy of the load? You now have two one shot groups. One of which may have been pulled but maybe not. You can’t measure accuracy this way.

Do as you will but if it were me I would adjust the rear sight down halfway between the present setting and bottomed out. From there fire a five shot group rested and as steady as you can hold. Pay attention to being consistent here because you need the learn the accuracy potential of rifle and shooter as much as where the rifle prints. This will also suggest to you the next adjustments if any, you need to make.

Again, if you’re serious about making a clean one shot kill, and you must be otherwise why handicap yourself with a muzzle loading rifle, you need to burn some powder and learn the rifle. Clean kills at 100 yards don’t happen haphazardly. Best of luck.
 
Yes. Still. How confident are you in the accuracy of the load? You now have two one shot groups. One of which may have been pulled but maybe not. You can’t measure accuracy this way.

Do as you will but if it were me I would adjust the rear sight down halfway between the present setting and bottomed out. From there fire a five shot group rested and as steady as you can hold. Pay attention to being consistent here because you need the learn the accuracy potential of rifle and shooter as much as where the rifle prints. This will also suggest to you the next adjustments if any, you need to make.

Again, if you’re serious about making a clean one shot kill, and you must be otherwise why handicap yourself with a muzzle loading rifle, you need to burn some powder and learn the rifle. Clean kills at 100 yards don’t happen haphazardly. Best of luck.


Thanks. I'm gonna try to work it out when I get a day off.
 
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