What the heck is happening??? 26 Nosler

[tbrice23]

It should have great sectional density and great BC. I've been searching and no one seems to have them.

 

[tbrice23]

Sorry, these are the 140 hunting vlds.

I am hesitant to using a target bullet on wild game. I want to be ethical

Check your private messages.

 

[clark33]

Yes the Hybrids have a thicker jacket, and should be easier to develop a load because it is supposed to be less seating depth sensitive.
They have a deep void under the hollow point which helps hydronic expansion . I'm considering hunting with 185Hybrids in a 300wsm. They have over .410" void.

Ok so would you start with the same seating depth as my most accurate load with the VLDs? i.e. I found great accuracy .035" off lands, should I start there with the hybrids?

 

[tbrice23]

That would be fine .035 jump. I'm shooting my 185gr HT at .015 jump.

There's a good chance that they will shoot the same from .005 to .040 jump

 

[Bullet bumper]

Are you using a cut rifled barrel ?

 

[clark33]

i believe Benchmark Barrels are button rifled

 

[Bullet bumper]

Ok that should not add any extra engraving on the bullet .
Definitely switch to the thicker jacket target bullet . What is the twist rate of the barrel and the length of the bullet ?

 

[clark33]

Ok that should not add any extra engraving on the bullet .
Definitely switch to the thicker jacket target bullet . What is the twist rate of the barrel and the length of the bullet ?

1-8 twist 26" barrel

 

[Bullet bumper]

stability calculates as fine so it has to be some kind of jacket break down due to heating . Check the bore is not rough . This sounds like the classic failure that Berger addressed with it's thicker jacket . Don't let the barrel get too hot between shots . Proper Moly coating could also help ease the issue .

 

[clark33]

I read through my notes last night and earlier this year I shot the same bullet, powder, and primer with .5 grains MORE of the load that gave me 3380fps and was only getting 3300fps. The only difference between the loads is the 3300fps was .020" off lands and this higher pressure one is .035" off lands. I clean my barrel after every 40 rounds or so but am wondering if I am developing a carbon ring near the throat causing the increase in pressure? Any ideas why I would see nearly a 100fps increase with 1/2 grain less powder and .015 deeper seating depth?

 

[Browninglover1]

I read through my notes last night and earlier this year I shot the same bullet, powder, and primer with .5 grains MORE of the load that gave me 3380fps and was only getting 3300fps. The only difference between the loads is the 3300fps was .020" off lands and this higher pressure one is .035" off lands. I clean my barrel after every 40 rounds or so but am wondering if I am developing a carbon ring near the throat causing the increase in pressure? Any ideas why I would see nearly a 100fps increase with 1/2 grain less powder and .015 deeper seating depth?

Many barrels speed up as they break in. If your barrel still has a low round count (less than 200) you probably had your loads speed up along the way. If your barrel has a higher round count than that, a carbon ring is a good possibility.

 

[clark33]

I am right around the 200 round mark. Would it really increase nearly 100fps with .5 grain less powder charge though? Have any of you experienced an increase like this before?

 

[Browninglover1]

I am right around the 200 round mark. Would it really increase nearly 100fps with .5 grain less powder charge though? Have any of you experienced an increase like this before?

Absolutely. I've seen barrels speed up 150 fps with the exact same load in the first 150 rounds on a 6.5x284.

 

[clark33]

Ok, good to know, I will try knocking the charge down a grain and a half or so and see what my velocities are. I spent last night cleaning the barrel thoroughly with patch out and butches bore shine with patches and a nylon brush. I also left a patch soaked in patch out sitting in the throat today while I am at work, I will remove it tonight and give it a few short strokes with my nylon brush just to be sure there is no carbon ring.