30-06 Trajectory

[Pumpkin Head]

Hello,

I have a question that is not related to reloading but I felt the participants in this forum may be the most qualified to answer.

Over the weekend I was checking the zero on my A-Bolt 30-06 in preparation for a hunting trip. I had the gun zeroed at 100yds and it checked out fine. I backed the target up to 200 yds, as I may be presented with a longer shot on my trip, and my group was a full 6 inches below zero. The windage was dead on with the 100yd group.

I was shooting a Winchester 150 grain pointed soft point and the barrel length is 22 inches. I did not have much time to work with it so I left things the way they were but I am trying to find out why there is such a drop in the point of impact. Please let me know if you have any ideas.

Thanks,
PH

[Adam Helmer]

PH,

When you say you "zeroed your rifle at 100 yards," do you mean it was point of aim/point of impact at 100 yds? If you are hunting big game, zeroing you rifle to hit 2 or 3 inches above point of aim at 100 yards will give you acceptable hunting accuracy out to about 300 yards. Many ballistic tables advise a +2 or +3 inch 100 yard zero that you need to check with your gun and loads at 200 and 300 yards to verify the drop.

Adam

[Pumpkin Head]

Adam,

The area I hunt normally has shots that are around 100 yards or less and we also shoot wild hogs using head shots so I like my POI to be right where I am aiming. So I set my rifle to be dead on at 100 yards. I know I should be able to raise the POI so that I can hold on the animal out to around 230yds - 250yds. However, I just did not expect this kind of drop in the POI from 100 yds to 200yd and am questioning if there is some problem I am not aware of. Is it possible that the load carries less powder than is prescribed?

Thanks,
PH

[Adam Helmer]

PH,

Is your rifle equipped with a scope? If so, set your scope to hit +2" at 100 yards for a point blank range of about 250 yards. When you aim at a hog's head, the +2 inches will not matter, especially if you are shooting offhand.

Adam

[Pumpkin Head]

Adam,

The gun is scoped and I know that the charts say I should be able to set it 2'' high and shoot to 250 yds. But based on my recent experience, if it is set 2'' high at 100 yds the point of impact will be 4" below my aiming point at 200yds. None of the charts show this kind of drop and the question is why did this happen? I should expect a drop of about 3" at 200yds, correct?

Thanks,
PH

[Rocky Raab]

PH, first a welcome to HuntChat.

Your rifle is not underperforming. If you are "on" at 100 yards, a six-inch drop at 200 is not out of line. You may be correct that your muzzle velocity could be a bit low, but it probably is due to that short barrel or any number of other factors, not a shortage of powder in factory ammo.

It might seem odd, but if you do as suggested and sight 2" high at 100, you will NOT be 4" low at 200. You'll be closer to right on at 200. It has to do with the way the bullet will arch between the muzzle and the 200 yard target.

Again, it might seem odd, but you'll also be closer to "on" for that up-close hog's ear shot if you sight 2"+ at 100. Sighted this way, you'll hit exactly where the cross hairs are at a range of about 30 yards, hit just slightly high from there to about 175 yards, and then be on again to slightly low out to 225 or so.

If you prefer to stick with the 100-yard zero, just remember to hold a touch high for longer shots.

[Catfish]

PH,
Let me also welcome you aboard.
Most of the charts your looking at are for when the center of the scope sets 1 1/2 in. above the center of the bore. If your`s is less you can expect alittle more drop at 200 yrds. and if it`s higher you can expect alittle less drop. Checking my charts you should expect about 6 in. if your 150 gn. bullet is fired at abt. 2,400 fps. Factory loads should be around 2,900 fps. from a 26 in. barrel and if you lose 125 fps. for each in. of barrel that would put you about right on. BUT,,, you should lose only about 50 fps. per in. I`m not really sure what is happening and don`t know if I could if I seen your set-up, but as long as you know where your gun is shooting that`s really all that matters.

[quigleysharps4570]

Just out of curiosity...what was the temp when you sighted it in?

[Pumpkin Head]

Thanks for the replies. The temperature was about 60 and the humidity was about 40% and there was only a very slight breeze.

I did not measure the height of my scope but it is not very high. It has a 40mm objective and I use the low or medium turn in Leupold mounts. I like my scope to be mounted as low as possible and still maintain clearance from the barrel.

I really do appreciate the input, I am a hunter not a target shooter. But I do insist on accuracy because I do not want to wound any animal. I have been hunting now for about 30 years and have just never experienced this before. In the past though I had the rifle set about 1.5-2" high at 100yds so perhaps this drop is normal for a rifle sighted in to zero at 100yds. It looks like I will be moving the POI up a couple of inches again.

PH

[Rocky Raab]

There ya go!

Learning strikes again. LOL!

I'd bet that you're getting about 2600 or 2700 fps from that rifle. Factory ammo for the '06 has been dialed down a bit over the past few years in deference to the indisputable fact that there are now .30-06 rifles out there that are a century old.

(Anybody realize that this is the 100th anniversary of the grand old round?)

That being the case, the SAAMI officials have lowered the maximum allowable pressure of factory .3-06 ammo, so even those old rifles will still be safe to shoot.

For rifles made today, reloading is the way to spruce up the '06.

[Evan03]

hornady still stokes up the 3006 light magnum ammo.

[Evan03]

165 light mags at 3018

and 180 light mags at 2900.

im not even pushn my 3006 that hard with 165gr bullets.

[PJgunner]

PH. Rocky is right on the money about the 30-06 being downloaded by the factories in deference to all the old guns still in use. What does gripe my gut is they still advertise 2900 FPS for 150 gr. bullets and 2700 FPS for 180 gr. bullets.

Not so in real life. I got a smokin' deal on a large batch of Winchester 180 gr. Silvertips from a Supwer K-mart that was closing it's doors due to the fact that the Walmart across the street was beating the pants off them. The 30-06 is one of my all time favorite cartridges and I have more than a few rifles chambered to the round. I ran a series of tests with that ammo over a chronograph and the results were shocking to say the least.

I used three rifles, one each with a 22", 24" and 26" barrels. I clocked five rounds from each rifle over the chronograph.
The 22" rifle would barely pass 2600 FPS, the 24" rifle 2625 and the 26" rifle barely made 2650 FPS. I have two rifles with 26" barrels, so I ran five rounds through the second rifle and got 2640 FPS average.

Pretty shocking, if I do say so myself. Actually, even before the factories downloaded the 30-06, the round has never been loaded to it's full potential by the factories, again, in deference to old those "golden oldies" still in use. The reloading data in the manuals reflects the same caution.

I wonder? The 06 is loaded to 48,000-50,000 C.U.P. according to most of the manuals that give pressure data with a few loads in P.S.I. that show pressures about 56,000 P.S.I. Take two rifles of the same make, say the Winchester M70, one a 30-06, the other a .300 Win. magnum. The magnum is loaded to 60,000-65,000 P.S.I.. My question becomes, if that M70 can hold the 60 to 65K pressure of the .300 Magnum which has a greater bolt thrust, then why can't a 30-06 be loaded to that same pressure in that same make modern rifle? It certainly could, if one could find the proper pressure tested data, but don't hold your breath. Kinnd of makes one wonder. I wonder if the people at Speer, Hornady, Nosler, etc have worked up those loads in their labs for their own private use? Sure would be nice to know.

Guess my point is, you ain't getting what you paid for as far as advertised velocity is concerned. I couldn't say what the 150 gr. Winchester load puts out as I haven't used a 150 gr. bullet in any 30 caliber rifle for over 30 years now. I do know that you can easily load up a 150 gr. bullet to close to or a little above 3000 FPS depending on what your ridfle likes and how careful you are. They sure do mess up a lot of meat loaded up that way though. I like my 180 gr. loads at close to 2800 FPS or a little above, depending on which rifle and barrel length is involved.
One caveat though. Unless you are very experienced in handloading, and even then, I do not recommend going past max load data in the manuals. Anyone that tries it does so at their own risk.
Paul B.

[Jack]

No doubt the 30-06 isn't loaded to as high a pressure as modern bolt actions can handle.
There's still a lot of M-1 Garands out there, though- and they were designed to work with 30-06 ammo loaded to 45,000 C.U.P.
And a few 1895 Winchesters are still floating around, too. And low number Springfields. Not to mention tons of Springfields sporterized by who knows who.
So, I can see why the factories load the 30-6 to the lower pressures that they do.

[Evan03]

i think the 3006 is right at home wether loaded hot or slow. it does it all no matter what.

ive got 165s movn alittle slow and 125s smokn. its just a fun caliber to reload.

Evan

[Evan03]

recntly i tested some more 165gr bullet with h4350 i found it shoots better with a fuller case and hotter loads. im now pushn 165s in the 3000 area

im workn on getting 180s into the 2800s