BHK says,
My guess is that one company or the other goofed on the box data, or that they were using different zeros to calculate the 100 yard drop.
Possibly true.
But there are a lot of unstated variables in these ballistic tables. One of the more important ones is line-of-sight to axis-of-bore distance.
In general, a higher line of sight will give the impression of a flatter trajectory if two rifles are sighted in for the same intermediate range. This is because the angle of departure is greater with the higher line of sight. *
This line-of-sight to axis-of-bore distance is rarely stated, but can be quite different for an iron sighted .22 versus a scope sighted one.
I don't know offhand if SAAMI has any standards for this.
In any case, all you can do is take the ballistics quoted by the manufacturer as a guideline to get you on the paper, and then determine the trajectory for
your firearm empirically.
I once taped a range table for Remington .22LR High Velocity HPs to the side of my favorite
scoped bolt .22 rifle. I took the numbers right off the manufacturer's data sheet and zeroed the rifle at 25 yards, which was what the table said.
I soon found that at 100 yards my shots were about an inch higher than the table would have me believe. Now with a .22, with an effective humane hunting range of (at the most) 75 yards, it wasn't all that critical, so I just remembered that the table was off and compensated with "Kentucky Elevation." This method was used for hunting dangerous game like pop bottle caps at random ranges.
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* To visualize this, imagine some extreme cases: two rifles zeroed at, let's say 50 yards, but one with close-to-the-bore-axis iron sights, the other with a telescopic sight mounted 1.5 inches, then 5 inches, and then 10 inches above the bore line.
You'll notice that with the scope mounted at the (ridiculous) height of 10 inches above the bore, the angle of departure must be greater for the bullet to strike the zero point at the stated fifty yards.