Longest shot +1500 yard hunting?

[WildRose]

I finally got to fire a Rd at 2055 yds just at dark this evening. The target was a 36in by 36 in steel plate painted red with a 12in white circle. It was pretty hazy and visibility was pretty poor. The plate was sitting in front of a vertical rock wall. I dialed it in and struggled to see the target, I finally got everything set, in focus, and touched it off. I was shooting alone and did not see an impact anywhere.

I started to fire another Rd but light was fading fast so I decided not to waste any more ammo. I drove up to the target to see if I could find where the Rd impacted. There it was at 7 o-clock right in the edge of the white.

I'm beginning to think this 6.5-13 gain twist and the 425 CE is a real deal.

This accelerating twist idea intrigues me.

Faster twist slower bullet, higher pressure. Less twist in the first foot of barrel it would seem would lower pressure and allow for higher velocities because less force is needed to push the bullet but as the bullet travels down the tube and the twist increases since there is still powder burning and gas expansion the pressure would then be more even throughout the length of the barrel.

Interesting concept. We'll see I guess if more mfg's try this on a wider range of calibers in the future.

 

[LR3]

Great shooting Augustus. Please keep us updated on your progress. I once shot Dave Viers progressive twist 375/408 and it was very accurate.

 

[Broz]

Augustus, Very good shooting. That is awesome. 1/2 moa accuracy at 2000 plus.

Nice going.

Jeff

 

[codyjoe1128]

U guys could have an ATF (Achohol, Tobacco, Firearms) party...

Don't trip the chatter alert, it really doesn't take long for the black choppers to show up.....

I'm in if a newb can come along, ill even buy the beer...it would be like the ultimate in long range shootin classes with all you guys there!
Let me know when and where( at least where I can park my 72' of semi) ill bring my 300wsm ( I know I know its a pea shooter in this case but somebody has to shoot the yotes that get too close lol!)

 

[Augustus]

Well it is looking promising but in the grand scheme of things there still has been limited numbers of these shot. I have no idea if the gain twist has anything to do with accuracy, I really believe a conventional 6.5 twist would work.

If the conditions permit I will try to get to 2500 this evening. The wind has been pretty stiff up in the day and dies down just at dark leaving a narrow window for testing. I'm more interested in testing the platform than my wind doping skills which ain't all that good.

 

[Jordan Smith]

This accelerating twist idea intrigues me.

Faster twist slower bullet, higher pressure. Less twist in the first foot of barrel it would seem would lower pressure and allow for higher velocities because less force is needed to push the bullet but as the bullet travels down the tube and the twist increases since there is still powder burning and gas expansion the pressure would then be more even throughout the length of the barrel.

Interesting concept. We'll see I guess if more mfg's try this on a wider range of calibers in the future.

Gain-twist barrels have been around for a long, long time. They work, but the benefits over regular twist barrels are debatable. Those that prefer them to standard twist barrels are usually shooting lead bullets. Lots of info on gain-twist rifling if you Google it.

 

[Augustus]

The info I am interested in does not exist. My concern is that since the twist rate I am using is fairly extreme, a conventional barrel could shear the drive bands on banded bullets. The CE bullet will probably be more likely to withstand the forces because the shaft of the bullet is somewhat engraved though not to the extent of a jacketed bullet or the Jamison solid.

I am pretty sure a conventional twist this tight has not been tested with banded bullets. A 6.5 twist in 375 is comparable to a 5.5 twist in 338 so there is some serious twisting. One of the reasons for using the gain twist is to reduce the pressure on the bands by spreading these forces out over a longer period of time. There also seems to be some advantage in torque reduction.

I am not even sure if a twist rate this tight is required to stabilize the 425, I would like to see someone fire them from slower twist and see where they start having issues. It may be they will work from an 8 or so. I could tear my rig apart and screw on my 8 twist barrel but it has not impressed me very much with any bullet.

 

[Jordan Smith]

Yup, those advantages have always been the heralded benefits of gain-twist barrels, and many have seen that they do what they are claimed to do. The only downside that I'm aware of is the expanded deformation on the bullet shank/driving bands due to the large change in rifling angle, relative to the bullet's center axis, which causes a pivot point in the driving bands and results in larger areas of deformation where the rifling engraves the bullet. This drawback is outweighed by the benefits that gain-twist rifling offers, IMO, and I can absolutely understand your favourable attitude toward the barrel you're using.

 

[Darryl Cassel]

Sounds like you have a winner there.

 

[WildRose]

Gain-twist barrels have been around for a long, long time. They work, but the benefits over regular twist barrels are debatable. Those that prefer them to standard twist barrels are usually shooting lead bullets. Lots of info on gain-twist rifling if you Google it.

It's been around a long time but as you said normally for cast lead bullets, and of course some artillery.

This is a different application which is why it's an interesting concept.

 

[Jordan Smith]

It's been around a long time but as you said normally for cast lead bullets, and of course some artillery.

This is a different application which is why it's an interesting concept.

Yeah, and it seems to be working out just fine, which is cool. An excellent barrel maker that lives close to me makes a lot of gain-twist barrels, which get used in local competition a lot. I'm thinking about throwing one of his gain-twist barrels on one of my rigs next time I need a new tube. Possibly something like a 14-8" twist in 7mm to launch those 195gr Berger EOL bullets that are supposed to come out sometime soon.

 

[Augustus]

Guys, I don't know if the gain twist adds anything positive to this system. It is my opinion that the reason this system is working is that the 6.5 exit twist is compatible with the 425 and the projectile is very stable. The barrel is a good one but if a conventional 6.5 twist launches this same bullet at the same velocity I doubt there would be any difference in performance providing the drive band can stand the forces generated.

 

[WildRose]

Guys, I don't know if the gain twist adds anything positive to this system. It is my opinion that the reason this system is working is that the 6.5 exit twist is compatible with the 425 and the projectile is very stable. The barrel is a good one but if a conventional 6.5 twist launches this same bullet at the same velocity I doubt there would be any difference in performance providing the drive band can stand the forces generated.

Gus I'm thinking one advantage is going to be extended barrel life vs standard twists.

With the initial slow twist reducing maximum pressures and thus heat, I would think there's got to be substanitally reduced throat erosion per round.

Theory only, but a sound one. I'll keep my eyes open and looking for reports on how the gain twist barrels are working out and maybe one day try one if the reports keep being positive.

 

[WildRose]

And you don't control animal movement after the bullet leaves the muzzle.

Which does not change irrespective of range.

The longer the range the wider the variables become which is why precision equipment and an experienced shooter/hunter will always think long and hard about pulling the trigger be more diligent in determining if the "shot is right".

Whether it's a 25yds quick shot in the brush or 2,000yds away, ultimately the only person who can make such a determination is the man/woman behind the trigger.

You will find that in this crowd we pride ourselves on using absolutely every lawful advantage we can find to ensure that when we do decide the "shot is right", it is. We are all willing to accept the responsibility which follows the release of the trigger.