Actual bullet drop vs advertised

[FlGunner]

Hello all, new to this forum. Just had a quick question on bullet drop. Have you guys had any experiences where your actual drop in trajectory is quite different than advertised? (Factory ammunition). My set up is a Remington 700 sps varmint 26" bull barrel. Vortex PST 4-16x50 moa on Leopold based and rings. I currently do not reload yet and have been shooting Hornady Superformance SST 165.
What I've experienced is the rifle/load doesn't seem to have the drop that is advertised. With a 100 yd zero, the SSTseems to shoot rather flat out to around 225. What I've read and found on a few online ballistic calculators is that it should be close to 3.5" low at 200 and about 7.5" low at 250 yds. So I'm sure it'll be even more drastic at extended range. Hornady normally used a 24" test barrel according to cs there but I wouldn't think that 2" of barrel would make that kind of a difference. Just looking for a little advise on how to go about doping my rifle. Is the best practice to shoot it at (x) yardage and simply measure real world drop? My current range limitation is about 600. I can try and post a pic of 100 yd cold bore impact (I'm a hunter so that's the shot that I'm most interested in, given that's the most important one in the field). Anyway it's landing in the top half of a 1" stick on target.

 

[Barrelnut]

Is the best practice to shoot it at (x) yardage and simply measure real world drop? My current range limitation is about 600.

Welcome to the forum.

You can definitely do that. Tape the info to the butt of the rifle and use it for holdover or dial for the longer shots.

Actual drops versus factory drops do vary from rifle to rifle. Altitude even affects it. Bullets shoot flatter in the Rockies than in Florida at sea level due to less atmospheric pressure. A 26" barrel might shoot 50~80 FPS faster than a 24" barrel. About 25~40 FPS per inch, it varies.

You don't mention the cartridge your shooting? But most cartridges shoot 1" to 1.5" high at 100 yards, when zeroed at 200 yards. I like to zero my rifle at 200 yards. That way, at 100 yards it is only 1.5" high and that is still well within the kill zone on a deer at 100 yards. Then I can shoot at 300 and record the drop, so I know how much to hold over and I'm good to go.

Might want to try a chronograph someday. The difference between what a chrony says and what it says on the side of the box can be an eye opener sometimes.

 

[FlGunner]

I forgot to mention that my current cartridge is the Hornady Superformance SST 165. I'm just new to the shooting at distance game and want to get proficient enough to be an effective hunter at 500. I've never used a chronograph but have heard that factory ammo can be very inconsistent. The SSTs seem to shoot moa at 100 for me (3/4-1") if I do my part. I will get out and shoot at different intervals and see what kind of results I get and go from there. Thanks again for the help. I always welcome any advice.

 

[rcairflr]

If your rifle is truly zeroed at 100 yards and you have no drop out to 225 yards, then your bullet is defying the laws of gravity.

 

[Barrelnut]

I forgot to mention that my current cartridge is the Hornady Superformance SST 165.

Is you rifle a 308 Winchester of some type?

 

[FlGunner]

It's hitting in the top portion of a 1" stick on bullseye so true center of bullet hole to center of bullseye may be an inch high. Not claiming to have a super rifle of some sorts just looking for a little help on getting understanding on what others have experienced. It is a 308 win. When I say it's shooting fairly flat out to around 225 is that it is not anywhere near 3.5"-4" low. I'm still hitting the bottom portion of the same 1" bullseye. Maybe it's a true 200 zero. I just would expect it to hit higher at 100 ( roughly 2"). I'm new to this caliber and long range dope. Previous experiences have all been with a 270 and 300 yds shooting with a 200 yd zero. Thanks for the replies.

 

[Barrelnut]

Your true zero might be at more like 150 yards and the bullet is still rising at 100 yards.
I would try zeroing it at 100 yards dead center and then shoot 200 exactly and see what the drop is.

 

[FlGunner]

If your rifle is truly zeroed at 100 yards and you have no drop out to 225 yards, then your bullet is defying the laws of gravity.

I just got done at the range on my lease, and you sir are correct. The rifle is at a 200 yd zero. I shot 5 shots from a lead sled and consistently hit dead on at 200. Rifle was about 1.75" high at 100. I guess the error before laid within me on a bipod. For what it's worth, I was also about 8" low at 300. So I think I'm in the ball park on why it's shooting like it is. Thanks for the help.

 

[rcairflr]

Glad you have it figured out.

 

[westcliffe01]

300 or 350 yards is a good range to start getting real insight into the trajectory. From zero to 200 the drop is so little that it can be masked by the kind of group sizes that the average Joe shoots. Now if you shoot one hole groups at 100 yards, it will be a little clearer... But a good rifle and either steady or no wind should see one shooting 2" groups at 300+- yards. If you combine that with tiny groups and carefully measured point of impact at 100 yards, one can get a good idea of what is going on, especially if one does not own a chrono. Also known as a lie detector...

 

[Canadian Bushman]

300 or 350 yards is a good range to start getting real insight into the trajectory. From zero to 200 the drop is so little that it can be masked by the kind of group sizes that the average Joe shoots. Now if you shoot one hole groups at 100 yards, it will be a little clearer... But a good rifle and either steady or no wind should see one shooting 2" groups at 300+- yards. If you combine that with tiny groups and carefully measured point of impact at 100 yards, one can get a good idea of what is going on, especially if one does not own a chrono. Also known as a lie detector...

+1

Its very easy to establish a bad zero at close range.

 

[ltcjwb]

I found the 2-0-8-24 law on another forum. Most common hunting (and target) rounds follow it. If you zero at 200 yards, your bullet strike will be about 2" high at 100, 8" low at 300, and 24" low at 400. If you check the data, you will see that it is not far from correct, no matter what you are shooting, from 150 grain FMJ to 210 Berger HVLD. Yes, guys, a fast bullet will be 1/2" lower at 100, and a big one will be 2" inches lower at 400, but they are all in the ball park. And they will all hit within an 8" kill zone if you do your part.

2 - 0 - 8 - 24 | Hunting Rifles | 24hourcampfire

 

[wackinandstackin243]

The info on the back of the box leaves out some key pieces of data if you are really wanting to be exact. Elevation and temperature will be the big ones. As velocity changes, your drop will change. Your best bet would be to get your exact velocity if at all possible.The rumor going around when the superformance line came out was that it wasn't very temp stable. I wouldn't know, I have never tried it.