I put some XS sights on my Marlin 336BL and it is shooting about 2.25" high at 13 yds. That's the furthest I was able to shoot until I can get to an outdoor range. Can anyone tell me where it will hit at 25 yds?

18.5" barrel
Remington Core-Lokt 150 gr

Based on my calculations....

That arc is ridiculously steep. If you're hitting 2.25" high at 13 yards, that's like a 2-yard zero. It won't go back to zero until around 400 yards. At 25 yards that round will hit almost 6" high.

For a 100 yard zero (just suggesting one) you need to be hitting under a quarter inch low at 10 yards. That will get you close, but not dead on for a 100 yard zero because there is still too much variation.

That's what I was afraid of. What's odd is these sights are specifically for the 336, although probably for the 20" barrel. Would that make a difference?

Hold on... Info needed:

Projectile weight
Velocity at muzzle
Hight of sights above the bore
Rough idea of projectile BC--- most calculators already have built in.

Take those numbers and plug into darn near any reasonable online ballistics calculator and you will have good info.

A longer barrel will have a shorter front sight because the barrel itself makes up some of that height for the same angle. So yes, the wrong sights would be a major contributor to the angle. You need a taller front sight or a shorter rear sight.