Bullet drop, unexpected results

[inglysh]

I am shooting a tikka t3 in 270 win. I am zero @ 200 yards.
Shooting factory ammo out to 300, sighted in dead on, the bullets will hit dirt.
The loads that I am making drop about 10"...
Most of the factory rounds that I've seen call for between a 5-8 inch drop. I am guessing that factory rounds are dropping double that, if not more.
I haven't spent a ton of time shooting out to 300 so I didn't really know what to expect.
Rifle has about 200 rounds through it and shoots .65 moa.
I have not run it through a chrono.
Are these results surprising? Should the results be closer to the tables listed on the box or is that info really just BS?

If I back into the number based on what I know to be true, using MV as the only variable on a ballistic calculator, I have to back it off by almost 1/6 in order to achieve the bullet drop that is occurring between 2 and 300 yards.

Weight 130 gn
BC .452
Temp 68*
Humidity 38%
Pressure 29.91"
Wind 9mph left to right, gusting
Alt 750 ft

 

[venatic]

I would guess you are getting less velocity than the box says which is not unusual at all.
Just use the actual drop to figure your velocity using the ballistic calculator

 

[FearNoWind]

By my quicky calcs you'd have to be getting about 3000 fps to hold less than a 10 inch drop at 300 yards.
Run 'em through the chrono so you have more data to work with.

 

[inglysh]

I used the Hornady calculator and backed into the number based on the 10" drop from 200 to 300 yards. I landed on a MV of 2525 fps to make that drop occur.
Interestingly, it predicted that I was shooting 2.4" high @ 100 yards which is absolutely correct.
I will take a chrono to it and see what the results are. Will be interesting to see how close (or not) it is to what my estimation is.

 

[FearNoWind]

I used the Hornady calculator and backed into the number based on the 10" drop from 200 to 300 yards. I landed on a MV of 2525 fps to make that drop occur.
Interestingly, it predicted that I was shooting 2.4" high @ 100 yards which is absolutely correct.
I will take a chrono to it and see what the results are. Will be interesting to see how close (or not) it is to what my estimation is.

Sorry, inglysh. My first quicky calcs had your zero at 100.

 

[eshorebwhntr]

I typically like to use a further spread than a 200 zero and drop at 300 for ballistic traj validation.

If you can shoot to 450+ the calculation should just get more accurate the further out you go.

2525 does seem slow for any 270 with a 130gr bullet. Even for factory.