Strange trajectory for 270

MD

MD

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I went to the range to shoot some handloads yesterday to confirm what I had found on the last outing when 57 grains of h4831SC behind a 150 grain Hornady Interlock with CCI 200 primers in my 270 gave me the best accuracy at 100 metres.

It is a 1953 Husqvarna, FN action with a 24 inch barrel.

The 100 metre group was about 1 1/2 -inches in size and 2 1/2 inches above the centre of the target.

I'm no sniper and my handloading is done with a little Lee Loader kit with a scale, so 1 1/2 inches is okay with me at 100 metres.

But at 200 metres the group was 5-inches low.

That's a heck of a drop isn't it?

The theory was to try to get a group at 100 metres that would put me bang on at 200.
 
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2 1/2" high at 100 and 5" low at 200 is quite a big drop. The 1 1/2" group is fine for a hunting rifle. Have you chronographed your loads?
 
MD said:
No, I don't have a chronograph.
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Invest in one if you're serious about hand loading. Sure showed me a lot about my rifle and what I was doing with my loads. I learned I was pretty much wasting my time without one.

You don't have to go all fancy, my chrony seems to be confirming my loads as much as a pricier unit.

Barrel length and chamber dimensions will seriously make a difference in velocity.
 
Very often your trajectory will be different than what the book says, which is why it is important to actually test your rifle. Maybe try again, and see if the results are the same.
 
At 57 grains, I'm already over max in my Hornady (4th edition) reloading handbook and Hodgdon Internet site max.
 
MD said:
At 57 grains, I'm already over max in my Hornady (4th edition) reloading handbook and Hodgdon Internet site max.
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I can tell you from experience with all of those components in a factory rifle your shooting roughly 2750fps out of a 24" tube. I went all the way up to 58.5gr of H4381sc and started getting 2875fps. By all accounts you should be able to reach 2900fps or more with that combo. You follow the speed which is why a chrono is handy.
 
MD said:
I'm no sniper and my handloading is done with a little Lee Loader kit with a scale, so 1 1/2 inches is okay with me at 100 metres.

But at 200 metres the group was 5-inches low.

That's a heck of a drop isn't it?
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That's gravity. Perfectly normal, use a ballistics program and you will see that it is not a strange trajectory for a .270. Just mark your scope turrets for 100, 200 300 yards and adjust in the field. Kudos for testing, most people think they don't need to adjust elevation for distance.
 
Juster said:
That's gravity. Perfectly normal, use a ballistics program and you will see that it is not a strange trajectory for a .270. Just mark your scope turrets for 100, 200 300 yards and adjust in the field. Kudos for testing, most people think they don't need to adjust elevation for distance.
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Maybe gravity for a muzzleloader...1.5" high at 100 yards should put you close to bang on at 200 with most modern arms...something changed that you are overlooking.
 
You're going to have to back up and check everything, starting with pulling down a load or two and checking the charge. Is there any chance that you loaded 47 grains instead of 57? For a scoped rifle to produce the trajectory you describe with the 150 gr Hornady the velocity would have to be about 2000 fps.
 
Juster said:
That's gravity. Perfectly normal, use a ballistics program and you will see that it is not a strange trajectory for a .270. Just mark your scope turrets for 100, 200 300 yards and adjust in the field. Kudos for testing, most people think they don't need to adjust elevation for distance.
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It's gravity alright, but certainly not a normal trajectory. I have used 270 rifles for the better part of 50 years, and every 270 sighted in 2 1/2-3" high at 100 was always still above line of sight at 200 yd.

Something missing in the equation here. My guess is you have very low velocity for some reason. Are you using spitzer or round noe bullets? That would account for some of the excessive drop, but not all of it. RN bullets should be close to right on at 200 yd.

Ted
 
Why not? said:
It's gravity alright, but certainly not a normal trajectory. I have used 270 rifles for the better part of 50 years, and every 270 sighted in 2 1/2-3" high at 100 was always still above line of sight at 200 yd.

Something missing in the equation here. My guess is you have very low velocity for some reason. Are you using spitzer or round noe bullets? That would account for some of the excessive drop, but not all of it. RN bullets should be close to right on at 200 yd.

Ted
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Ted is bang on!!
I sight my 270 [150 Partition at 2925] +3" at 100, and it is still about that much above center at 200, or even a bit more. The bullet crosses through the line of sight at about 270 yards, and is 2.5" low at 300.
Something is very much amiss with your trajectory.
Eagleye.
 
"Something is very much amiss with your trajectory."

I know, that's why I'm whining here.

Anyway, I checked the load, it is 57 grains.

I'll just have to try some incrementally hotter loads I guess.

The reason I loaded up the 57 grains was because on my previous trip to the range I had tried 55, 55.5, 56, and 56.5 and 57 and 57 was the most accurate.
 
If it's an accurate load in your rifle just chrony it then build a chart from that. IMHO accuracy is much more important than the flattest possible trajectory.

That said, if you are way below published velocity for that powder/bullet you might have room to push it farther. There's really no way to know without chrony'ing your load.
 
Here is something else that will add a bit to the huge drop at 200.
Here is a picture of my notes from about 22 years ago, when I checked the difference in H4831 powder, between the old WW2 surplus and the new Hodgdon's they were putting up in cannisters.
The picture is self explanatory.
Also, I see in my 270 notes that I was using 59 grains of the old surplus powder, with 150 grain Norma bullets. I don't see a chrono repoort for that, but when sighted 2 1/2-3 inches high at 100, they were a little low at 300 and 34 inches low at 500.
By the way, this was tested on your range at Beaverly, Eagleye!
June16005.jpg
 
Bruce you must have one hell of a personal information depository!

When I was using my 270 exclusively as my moose rifle using factory federal round nose soft point 150 grain I had it zeroed at 100 yards. From my blind my shots were always at 275 yards (checked by range finder years later).

I'd aim just below the hump and get them in the heart so that's a drop of about 24" @ 275 zeroed @ 100.

That's about double the drop my ballistics software predicts so it's important to know velocity out of your rifle.
 
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