270 loads different POI horiz ??

Finally got my 270 out today to test some loads.

130 GK and 95 gr TTSX.
All over RL17.

I sighted the rifle in with the 130 GK's which were shooting excellent. 3/4" or so with an occasional through the same hole.

Figured the 95 gr TTSX should be shooting a bit higher which it was but it was shooting about 5" to the right.

I have had that happen before with different rounds, but not to that degree.
I assume it is torque but I dont really understand it and why it is that much difference.

Both were max loads. The 95 gr about 3600 and the 130 about 3150.

I did not chrono the loads that is just from data.

I has a rear bag and a front rest, and was shooting basically standard style, good cheek weld, semi firm grip, light forearm grip.
I had intended to use the same scope setting for these loads but looks like that may not work.

My .243 Weatherby does the same thing. groups string left as the weight goes up. I have mine "zero'd" with 66gr. HP's, the 55's print 3/4" right of that, the 95's 3/4" left of that. I reset my turret zero's on my Diamondback for the 65's, and adjust 3 clicks either way, depending on which bullet weight I'm using. The funny thing is, they all print almost exactly the same on elevation. I think this is because the velocity for each given weight is at the top end of the range, nearly 4100 for the 55's, 3800ish for the 65's, and 3100 for the 95's.

If your turrets can reset, you might experiment and find an answer similar to what I did.

I was hoping I could line them up a bit better.
3/4" would not bother me but 4"-5" is a bit much.

Instead of shooting both I think I will just settle on one bullet which will probably be the 95 gr barnes for now.

My intention was to shoot inside of 4" out to 300 yards. According to my calcs I should be getting 3700 fps at my max load
which would put me zeroed at 265, -1.7 at 300, -10 at 400.

The 130 GK is not bad either.
May hunt with both next year and just see how it goes.

Thanks

Quote:

---

Originally Posted by tammons

Finally got my 270 out today to test some loads.

130 GK and 95 gr TTSX.
All over RL17.

I sighted the rifle in with the 130 GK's which were shooting excellent. 3/4" or so with an occasional through the same hole.

Figured the 95 gr TTSX should be shooting a bit higher which it was but it was shooting about 5" to the right.

I have had that happen before with different rounds, but not to that degree.
I assume it is torque but I dont really understand it and why it is that much difference.

Both were max loads. The 95 gr about 3600 and the 130 about 3150.

I did not chrono the loads that is just from data.

I has a rear bag and a front rest, and was shooting basically standard style, good cheek weld, semi firm grip, light forearm grip.
I had intended to use the same scope setting for these loads but looks like that may not work.

---

Please forgive, But I cannot see what range you were shooting at.

100 yards

I have had the same thing with the Barns bullets, in my .270. I believe it has to do with the Barns bullet being a solid copper and harder bullet than the GK.
I shoot 150 GK or 160 Nosler Partitions in My .270.
If I want to shoot lighter bullets I go to my 7-08 or 22-250.

I have been loading and shooting my .270 for a couple of years now. I have experienced a lot of "interesting" results that I thought were my fault. One of these interesting times was a similar experience trying to dial in a 110gr vmax bullet. My plan was to get the 110 gr to shoot reliably within a couple of vertical inches of a 130gr deer load.

The first load I tried was under max, but still should have chronographed faster than the 130gr loads. They shot 2" low and about 4" right. I tried changing seating depth, powder, etc. but gave up after a couple of tries.

In the end I settled on one load as well, however I would be interested to hear some more feedback on this... I've still got a bunch of those 110gr vmaxes laying around and the woodchuck invasion is about to begin....

Think I figured it out by reading some torque threads over at 6mmBR.
It has to be torque as I was not holding the rifle very tight today.
IE the torque is acting on the rifle before the bullet leaves the barrel.

Think I will go back to the range and put the death grip on it and see if that will pull the 130 grainers in a bit.

...sounds like the bearing surface is coming into play...less on tha Barnes...

Probably true and I did not think about bearing surface, but that would impart less torque on the barrel.

So far 3 different people including me, 3 different 270 rifles, all shoot about 4" to the right with 90-95 gr bullets.

Most be torque.