Strange trajectory for 270

[Juster]

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.

It isn't zeroed at 100. Gravity doesn't care what you think, use a ballistics program.

 

[LongBomber]

You sure your 200m line, isn't 300m? 2 1/2 high at 100 should put you about 5-6 inches low at 300. You would need to be down under 2000fps to drop that much at 200m. No scope adjustments? Any other changes?

 

[MD]

"No scope adjustments? Any other changes? "

It is 200 metres. Nope, didn't touch a thing.


I'll try some factory loads next time. I 've got a few Winchester 150s and Federal 130 cartridges kicking around.

 

[1899]

It isn't zeroed at 100. Gravity doesn't care what you think, use a ballistics program.

Pretty arrogant, and it seems as though you haven't carefully read the OP's initial post.

I'll let you in on a secret, a secret that is known to people who actually go out and shoot. Trajectory in real life is often quite different than trajectory calculated by a ballistics program.

Why Not? is 100% corect with his comment.

But maybe your first hand experience is different with your .270 Win. loads. Perhaps you can share your loads and test results with us.

 

[Xs24-7]

It isn't zeroed at 100. Gravity doesn't care what you think, use a ballistics program.[/QUOTE

If your ballistic program shows that a .270 shooting 1.5" high at 100 yards is 5" low at 200 yards...youv'e put in some very odd data...there is no possible way for this to occur. It defys physics, common sense, and the real world experience of every big game rifle shooter in the world.

 

[jjohnwm]

It isn't zeroed at 100. Gravity doesn't care what you think, use a ballistics program.[/QUOTE

If your ballistic program shows that a .270 shooting 1.5" high at 100 yards is 5" low at 200 yards...youv'e put in some very odd data...there is no possible way for this to occur. It defys physics, common sense, and the real world experience of every big game rifle shooter in the world.

+1 on this. There's no earthly reason to shoot tiny little pills out of a .270 if you are forced to put up with .45-70 trajectories...this is probably going to be some silly little error in powder measurement or something similar, which will hopefully give you a funny little "DUH!" moment when you figure it out.

 

[crazy_davey]

It isn't zeroed at 100. Gravity doesn't care what you think, use a ballistics program.

 

[hawk-i]

I think Juster has been abducted by aliens or he has got some really potent weed.

 

[hawk-i]

and I'm kind of leaning away from the alien theory

 

[A-zone]

Why don't you zero your load for 200 and see where it puts you at 100. You may be pleasantly surprised that it's not that bad.

Either way, it would be interesting to see what the POI is at 100 yards with a 200 yard zero.

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.

 

[07blackwater]

+1 on this. There's no earthly reason to shoot tiny little pills out of a .270 if you are forced to put up with .45-70 trajectories...this is probably going to be some silly little error in powder measurement or something similar, which will hopefully give you a funny little "DUH!" moment when you figure it out.

I dunno. I've seen some pretty crazy trajectories out of my '53 760 with factory ammo. I have a feeling if it's got an old worn chamber velocities can get pretty low.

 

[Xs24-7]

I dunno. I've seen some pretty crazy trajectories out of my '53 760 with factory ammo. I have a feeling if it's got an old worn chamber velocities can get pretty low.

In order for his trajectory to be this bad his velocity would need to be south of 2000 fps....any chamber fd up enough to cause a drop in pressure significant enough to cause this would show numerous other symptoms...like blown brass...pieces flying,etc...if I had this issue I'd be taking a hard look at my scope...

 

[07blackwater]

True enough.

 

[Pathfinder]

Are you using a scale or just the lee scoops ?

The scoop is fairly ballpark, I use them to get close on my scale but I wouldnt' trust them to give me a specific load everytime.

As others mentioned im sure you are not getting the 2850 fps you should be getting on a max 150gr. load.

 

[shortaction]

Any chance you are zeroing your scale with the ball at the 10grs increment instead of the zero.

 

[SoBored]

Are you using a scale or just the lee scoops ?

That's what I wondered, then I reread post#1 and he mentioned a scale.

Something is wrong here, 1.8" high @ 100 and 5" low @ 200? You might as well be using a 30-30 with 170 grainers.

If you run a Hornady 150 interlock through a ballistics calculator, you need to put the velocity down to about 2100 fps to get that trajectory.

 

[CanadaBoy]

Why not buy a box of commercial ammo and shoot it in your rifle for a comparison. Just to completely rule out a rifle or scope problem

 

[MD]

"Why not buy a box of commercial ammo and shoot it in your rifle for a comparison. Just to completely rule out a rifle or scope problem."

I have some in my locker. I'm going to try exactly that.

 

[Why not?]

Maybe gravity for a muzzleloader...1.5" high at 100 yards should put you close to bang on at 200 with most modern arms.

.....If your ballistic program shows that a .270 shooting 1.5" high at 100 yards is 5" low at 200 yards

..... 1.8" high @ 100 and 5" low @ 200?

Actually, he posted that the group is 2 1/2" high at 100, and five inches low at 200.

That is 7 1/2 inches of drop between 100 and 200 yd. Something seriously amiss there.

Ted

 

[tylerjwitty]

maybe a mag primer is needed for so much powder...?? suggestion?