How to sight in a red dot at 100 yards?

[Starslinger]

I have a lever action .357 magnum with a red dot scope mounted on it. I want to shoot targets at 100 yards, but the unmagnified target is too far away for me to see where my shots are landing. I thought that I had it figured out by sighting in the rifle at 25 yards and looking at .357 magnum bullet trajectories, but I guess it I didn't do it right, because all my shots are missing the target completely. I think my shots are missing low, but I can't tell for sure. Also, I might not be using the same ammo that I used when I sighted in at 25 yards.

What is the proper procedure for sighting in a red dot for 100 yards, keeping in mind that I can see the red dot on my target at that distance, but I cannot see the bullet holes from 100 yards away. (And I'm not even on the paper at the moment...) The rifle, which is a Henry, is accurate at 50 yards, but I get almost zero hits at 100 yards.

Thanks for any help!

[Jesse 2]

How to sight in a red dot at 100 yards?

Use a video camera or iPhone with tripod


Sent from my iPhone using Tapatalk

[theLBC]

i believe 357 mag from a rifle should be relatively flat at distances up to 100yds. certainly close enough to hit paper depending on the muzzle velocities out of your rifle.

what rifle and ammo are you using?

try bigger paper or maybe ask for help spotting?



maybe something in here

https://www.shootersforum.com/marlin-1894-lever-guns/14660-357-44-lever-carbine-ballistic-curves.html

[Magilla26]

I have a Marlin 1894C in .357 This rifle shoots a 180 grain LBT hard cast at 1550 fps. If I sight my rifle for two inches high at 50 yards, I am dead center at 100 yards. This bullet has a low ballistic coefficient but is fairly flat out to 100 yards.

[RandyD]

Using two different loads just introduces an unknown factor, that you have to determine the impact. Stick to one load.

Take a friend with you to spot your shots at 100 yards, or sight in the rifle at 25 yards, then 50 yards, then 75 yards then 100 yards.

[baih777]

Spotting scope.
Sight in at 50 yds first.

[FishnHunt]

I would start out and 0 at 25 yards. lot easier to get on target for the first few shotes. check at 50 and then move to 100. should be dialed with in 10 shots.

[LynnJr]

With a generic 158 grain bullet going 1420 fps I would sight in at 25 yards dead on.
This should put you about 3-3.5 inches low at 100 yards.
If your off left right or up down more than 4 inches at 25 yards you won't be on paper at 100 yards unless you have a large target.
If your shooting by yourself get a good center at 25 then walk downrange between shots at 100 and never rest the barrel on your front rest only the forend.

[golfish]

You could buy a magnifier for the red dot. I found a nice used weaver scope on ebay for my Marlin.
How do you like the Henry?

[Tango_Down]

Tips:
Use a spotting scope of binoculars.
Use Shoot N C Targets to better see your shots.
Sight in 2-3" low and 100 yards first, spot on at 50 yards then go to 100.
Use this idea to sight in 2 shots.

https://www.youtube.com/watch?v=TiOpQY2ORo4

[Fishwishin]

If you cannot get a partner go back to basics and stick with same ammo. Zero in at 50, scoot back to 75, see what is going on, then go to 100. On Friday I verified my new, to me, Marlin 1894 (38/357) was hitting square on with +P .38’s. Today I shot it off of a soft pack at 100 and it was good to go (open sights), but I stayed within the same box of ammo. Unless your sight has gone screwy you should be experiencing the same, but you really do have to go back to the basics. Good luck, they are fun little guns!

[Powder_Keg]

Spotting scope makes a huge difference.

If your jump from 25 to 100 is giving you a hard time at 100 and you are not hitting paper, go back to 50.

You can also stack two Shoot and See target vertically to help walk in your shots.

[Thoughts]

Without a magnifier, I personally couldn't shoot accurately enough to get a good zero. If you want a 100 yard zero set, I'd try shooting at a couple of shorter distances to get good data, and then I'd use a ballistics program to give you the correct correction for 100 yards. Maybe 25 and 50 yards? With an accurate muzzle velocity measurement, the program probably would need only one point.

[damon1272]

So no one is touching on one a couple of important things with the red dot to add consistency. Turn your dot down in brightness as the dot will appear smaller. Use the edge at the top of the dot to aim with rather than the center. This will help you be more consistent even though you cannot see your hits. What others covered - sight in at 25 then go out t get your rise and determine you drop. Only use one load as changing up loads and brands may change your zero.

[SirRicky85]

Start from scratch. Use the same ammo while zeroing your rifle. Bore sight your rifle at 25 yards and adjust your red dot. Shoot target, make adjustments, and shoot target again to confirm... Get a bigger target since you can't make your calls. Shoot target at 100 yards. Walk down the range to see your point of impact. Put the same target over your hole align up with the bullseye. Walk back down the range and adjust your red dot. Shoot and confirm. Walk down the range again and it should be within 2 moa (or more depending on the red dot moa size you get) on bullseye since 2 moa is the smallest red dot you can get... (also assuming no user error on your side). Or... get a spotting scope to see your impact.