Hard to find good short range trajectory info on standard 38 loads (non +P).

From what I see, if I zero the full power standard 38 load of 3.5 Bullseye and 158gr SWC (swaged) at 25yds, it appears on at 25, a few inches high at 50 and on about 75. Only a brief test, but the 2 in M36 and 4 in M15 looked to both be similar this way.

Is that right? Is that what your experience has been?

And does anybody who zeros at 50 have info on the POI at 25?

I'll use these two for varmint control.

OK - now I see that doesn't jive at all with the calculator on handloads.com. It shows zero at 25 then all drops from there out. Not my experience at all. What tha??

Unless you're using a fixed rest to take the human factor out you really can't be sure what the ammo is doing.

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Hornady.com has balistic data for all guns if you need some "General info" on what your bullet will do with its BC,weight and velositys.

Nosler makes a great app for the iPhone.

I ran the Speer SWC bullet at 850 fps with a 25 yard zero and a .3" mechanical offset on the sights (sights .3" above the bore). Here is the rundown:

Yards. Drop

10. 0.19
25. 0.00
40. -1.33
50. -2.87
60. -4.95
70. -7.57

Ran the same bullet/fps/offset with a 75 yard zero and got this

10. 1.4
20. 2.61
30. 3.32
40. 3.52
50. 3.19
60. 2.32
70. 0.91
75. 0.00
80. -1.06
90. -3.60
100. -6.72

Ok... so do they do the lab testing in fixed vises where there is no barrel movement from recoil?

I'm assuming recoil accounts for the difference in what I am seeing on the range and these numbers, which do not match at all.

Mine zeroed at 25 are all high at 50, not low. Normally I pull a little low when firing single action.

What type of sight are you using? If it's a handgun scope or red dot mounted on a rail the offset between the sight and bore axis is the cause of the divergence you are observing. Typical offsets for rail mounted scopes and red dots can run as much as 2 inches or even a bit more. When you sight the gun in at closer ranges you create a situation where the line of the bore axis and the sight converge. This convergence can cause the POI to rise above the line of the sight at some distances beyond your initial Zero Point. How much depends on the initial Zero, the ballistic arc of the load, and the distance between the bore and the sight.

My rule of thumb is that for a sight offset of an inch or less, measured to the center of the bore, I'll use a 30 yard zero. That will keep the POI within 1 inch of the sight from 20-25 feet out to about 120 feet for a 130 grain 38 spl. running 800-850 fps. or so. For the 40 S&W the same setup will hold within at inch from 20 feet out to 135 feet for a 180 gn. load running 1000-1050 fps.

When I change to a handgun scope mounted on a rail I like to zero the sights at 50 yards. This results in the gun shooting high at intermediate distances but in general it's only about 3 inches high at the peak of the arc, IIRC that's around 50-60 feet with the previously mentioned 38 spl. However, don't hold me to that, it's been over two years since I fooled around with a scope on my 620. The ballistic arc will also intersect the line of sight somewhere around 30 feet but I didn't take the time to find the second intersection when I was fooling with that scope on my 620.

No scope, just factory sights.

Barrel rise from recoil from the not-so-fast bullet is the only explanation as far as I can see.

I'm not sure how scientific this is, but when I shoot Distinguished Revolver matches with my per-Model 14 with a Lyman 358311 (about 160 grains) and 3.5 grains of Bullseye, there's a 5 click difference in elevation between 25 and 50 yards.

All those paper data facts look sweet but in the real world when you go to the range and shoot at 50 and 100yard targets then see where the bullets hit at the 200 yard "Burn" with a spotter helping you, you will find that this data is not always as close as the real thing.
Just a little bit of lost energy from your loads for any reason will make your bullets drop faster than normal..........and velosity vs muzzle jump can also mess up the figures.
If you have the time ,take the fastest 110 or 125jsp bullet that you have against the (if safe) +p 158 Lwc in your 38 out to the range an shot at some thing 200 yards away (with a rest)and compare the difference in drop.
This test opens your eyes up even more if you have a 357 magnum and shot a 125 and 158 JHP per bullet drop.

A steel Pig at 100 yards will also work, to let you know how much more front sight you need with a 38 vs a 357 mag with a "Standard" load.