Frustrated with the 1-12 twist and 40gr bullets

[Grayfox]

When the 204 Ruger cartridge became avaliable I bought a Savage 16 FSS rifle to see if I would like this cartridge better than my 223 Rem also in Savage 16 FSS rifle. The 204 Ruger had less felt recoil and had alot less bullet drop. So I decided to buy a Savage 12 VLP in 204 Ruger as my heavy barreled varmint rifle. This year I put together a heavy barrel AR 15 in 204 Ruger. All of these rifles have a 1-12 twist.

In April of 2005 I started loading the 204 Ruger. I called Hodgdon Powder and talked to their technical Person about reloading the 204. He said to use tubular powders and Fed GM205 Match primers gave the most uniform results. I checked all the gun magazines for loading data and there accuracy of 32gr and 40gr bullets.I had Benchmark and Rel-15 powder and 32gr and 40gr V Max's to start with. The load of 32gr v max,ww brass,fed gm205m primers,and 27.8gr of benchmark shot really well. It was going 4011 fps. My 40gr v max used the same primers and brass with 28.3gr of rel 15. This shot 3655 fps. It was ok but no tackdriver load like the 32gr bullets produced.

I was not happy with the 40gr bullet accuracy.Sierra came out with there 39gr and 32gr Blitzkings.I bought both Blitzkings and some H4895 powder.The 32gr Blitzkings and Benchmark were tackdrivers. The 40gr v max and 39gr blitzkings with h4895 and rel 15 were nothing to brag about. Rel 10X just came out and Sierra had some loading data for it. There max load of 25.1gr and there 39gr Blitzkings were super tackdrivers. Five shot 1/2" groups at 100 yards were consistant from both my AR 15 and Savage 12VLP. This load shoots like this in all four rifles we tried it in.

Nosler 40gr ballistic Tip and Hornadys 40 gr V max are also excellent bullets. My rifle's should be able to shoot these bullets with the same accuracy as the 39gr Sierras. Now I went and bought Rem 7 1/2 BR primers(Silverfox's recomendation),CCI #41 (AR 15 primer),BL C2 and Tac powder(Hodgden told me not to use ball powder).As you can see I am getting desperate to get the 40 grainers to shoot in my rifles. Some new combination has to work. All new powders get tested with the 39 Sierra's first. BL-C2 and the 39 gr sprayed all over my 2 ft square target at 200 yards from my Savage 12 VLP. Tac was even worse at 100 yards. Out of my AR the 8th shot keyholed and the 9th hit the target frame. The 10th shell jamed in the rifle and bent the case. It took me an hour to clean up the AR 15.

My friend has Wayne Blackwells "Load from a Disk" program. I asked him to run through the rate of twist to stabalize 204 cal bullets. Boat tail bullets need a faster twist than flat base bullets of the same weight. The 32gr needs a 1-14" twist.The 35gr needs a 1-13" twist. The 40gr needs a 1-10" twist. And the 50gr needs a1-9" twist.

A 1-12" twist would require a 37gr bullet as the optimum weight in a 204 barrel.

The 39gr Sierra is the closest to the 37gr ideal weight. With the right velocity and right powder it just becomes stable and is very accurate. The 40gr bullets(as well made as the are) just cannot overcome the too slow twist.

This next year I am going to get a 1-9" twist barrel to be able to shoot all 39gr to 50 gr bullets. I would hope that Sierra, Hornady, or Nosler would come out with a 37gr bullet and would be very accurate in all our rifles.

The 39gr Sierra Blitzking is the most popular bullet of 204 Ruger shooters on this web site. I think the 1-12 twist has somethink to do with that.

Thanks,Grayfox

[CV32]

A 1-12" twist would require a 37gr bullet as the optimum weight in a 204 barrel.

A 37 gr bullet of similar construction as the 35/40 gr Berger would definitely garner attention among the .20 cal shooting predator hunters.

[acloco]

Interesting.

Need to compare the "load bearing" lengths of the bullets. Regardless of outside shape, the length of the surface of the bullet determines the twist rate required.

Of note, usually, heavier bullets are longer, therefore, the load bearing surface is longer as well.

[skipper]

Grayfox

It seems odd that you have two rifles that won't shoot the 40's. Both my XR-100 and Panda will shoot the 40 gr. Bergers with the same or better accuracy as the 32 or 35 gr. bullets. Neither rifle liked the 40 gr. Noslers. Have you tried the 40 Bergers? My load was 25.1 gr. RE-10X, CCI BR-4 primers, and WW brass.

I was able to stabilize the 45 gr. Hornady's in my XR-100. I haven't tried them in the Panda yet. From my experience, the 1:12 twist is just the ticket with the exception of the 50 gr. bullets. If you go with a faster twist you might not get the same velocity. Faster is better, for me.

[glenn asher]

Skipper, neither of my rifles will shoot 40s worth a hoot, either. The Savage "sorta" shoots the Noslers okay, but not much under an inch and a half. Same with the CZ, both handle the Sierra better, but both shoot 32s a LOT better. I'm better off melting the Hornady 40s down for sinkers, neither rifle cares a bit for them.

[Grayfox]

Skipper

No I have't shot any of the berger bullets.

You stated that neither of your rifles will shoot the Nosler 40gr. I will bet that they will not shoot the 40gr hornady ether. This was the point I was trying to make about the 1-12" twist. Some rifles may stabilize some of the bullets of 40 grains. But not all 40 gr bullets. The 1-12 twist is on the very edge to stabilize this weight of bullet.

Today I called Sierra,Hornady, and Nosler and discussed 40 gr bullets.Sierra said they made the 39gr weight for this very reason of stability. There was some very interesting discussions about 40 gr bullet stability. We discussed the 37gr bullet weight in the 204 Ruger as possibly the ideal weight for the 1-12 twist to stabilize in all rifles. Since there are no bullets produced in that weight as of now, we will not know for sure. They said a 1-9" twist would be very good as it's better to over stabilize than under stabilize. It's easier to keyhole a bullet than to blow it up from spinning to fast.

Thanks,Grayfox

[Hawkeye Joe]

None of my Savage 204's liked the 40gr Bergers. The 40 Vmax's on the other hand, shot VERY well out of my VLP with H4895. Even the first 60 rounds of Hornadys factory 40gr loads were tackdrivers. I never had much luck with 35 Bergers until I discovered Benchmark. Thanks jo191145 and Skipper I now feed both my 204's the 35 Berger Benchmark load.

[Bayou City Boy]

Interesting.

Need to compare the "load bearing" lengths of the bullets. Regardless of outside shape, the length of the surface of the bullet determines the twist rate required.

Of note, usually, heavier bullets are longer, therefore, the load bearing surface is longer as well.

With all due respect, the load bearing surface of the bullet has nothing to do with barrel twist. Barrel twist is determined by the overall length of the bullet. A bullet is nothing more that a gyro. The longer the gyro, the more (faster) twist it takes to stabilize it...

If bearing surface had anything to do with barrel twist, long, and usually heavier VLD bullets, which typically have a very short bearing surface, would shoot well in slow twist barrels. They don't.

VLD bullets require a much faster barrel twist than conventional bullets to stabilize because of their length... In spite of their low bearing surface which is much less in relationship to the overall bullet length than you'd find with a conventional style hunting bullet that is shorter in overall length.

-BCB

[WrzWaldo]

Actually, barrel twist is calculated from the length to diameter ratio.

[acloco]

Interesting.

Need to compare the "load bearing" lengths of the bullets. Regardless of outside shape, the length of the surface of the bullet determines the twist rate required.

Of note, usually, heavier bullets are longer, therefore, the load bearing surface is longer as well.

With all due respect, ......

VLD bullets require a much faster barrel twist than conventional bullets to stabilize because of their length... In spite of their low bearing surface which is much less in relationship to the overall bullet length than you'd find with a conventional style hunting bullet that is shorter in overall length.

-BCB

You just reiterated what I stated.

VLD's have a high bearing surface (how much of the bullet is in contact with the barrel). Very Low Drag (VLD) are manufactured long to fly better (ballistic coefficient).

Agree that the bullet becomes a gyro, with a certain spin speed to make the fly, but, as I stated, heavier bullets are usually longer than lighter bullets of the same shape.

[Lee C.]

I've shoot only 3 different bullets in my 12fv. the 39grbk, the 35gr berger and the 40gr. berger. The 40gr. berger witch is by fare the most accurate bullet for me. I would sure like to know why all savage guns with the 1-12 twist barrels can't shoot the same weight bullets. You would think they could if they are made by the same comp. wouldn't you.

[skipper]

If two bullets with the exact same amount of imbalance are shot from a rifle that has a 1:12 twist rate and a rifle that has a 1:10 twist rate, the rifle with the faster twist rate will induce more dispersion than the rifle with the slower twist rate. It just makes sense to choose a twist rate that is just fast enough to stabilize the bullet you want to shoot and load for the node that yields the fastest velocity safely.

[Grayfox]

Lee C and Skipper

The reason rifles with a 1-12" twist will not shoot all 40gr bullets is that the twist is not fast enough to spin the bullets to really stabilize well. A 1-10" or 1-9" WILL make them spin fast enough to stabilize them. A 32gr needs a 1-14" twist and a 35gr needs a 1-13" twist. The reason the 32's and 35's shoot so well is that in reality they are over stabilized in a 1-12" twist. There is no one complaining about how poor the 32gr or 35gr bullets shoot.

This is not the case with 40gr bullets. They are on the edge of under stabilization. Maybe not to the point of keyholing, but you will never get the accuracy they are capable of. All bullets need a certain speed of twist to stabilize properly. A bullet over stabilized will stay above that speed longer than one that just barely makes it. An unstable bullet will never hit any where close on a long range target. But an overstabilized one will hit where you aim. Here is an example. I have a 260 rem with a 1-8" twist. I normaly shoot 129 hornady's in this rifle. Most groups at 100 yards are about 3/4". I can shoot 95gr varmint bullets into the same size groups. That 95gr bullet is going way faster and spinning an alful lot faster than the 129gr.
That would be considered way over stabilization,yet it shoots fine.

This is why you need a faster twist of 1-10" or 1-9" for your rifle to shoot all of the 40gr bullets. Or we need a shorter and lighter 37gr bullet for the 1-12" twist to stabilize.
Thanks,Grayfox.

[WrzWaldo]

The reason the 32's and 35's shoot so well is that in reality they are over stabilized in a 1-12" twist. There is no one complaining about how poor the 32gr or 35gr bullets shoot.

You cannot "over stabilize" a bullet. But you can spin them fast enough to come apart.

[Bayou City Boy]

Interesting.

Need to compare the "load bearing" lengths of the bullets. Regardless of outside shape, the length of the surface of the bullet determines the twist rate required.

Of note, usually, heavier bullets are longer, therefore, the load bearing surface is longer as well.

With all due respect, ......

VLD bullets require a much faster barrel twist than conventional bullets to stabilize because of their length... In spite of their low bearing surface which is much less in relationship to the overall bullet length than you'd find with a conventional style hunting bullet that is shorter in overall length.

-BCB

You just reiterated what I stated.

VLD's have a high bearing surface (how much of the bullet is in contact with the barrel). Very Low Drag (VLD) are manufactured long to fly better (ballistic coefficient).

Agree that the bullet becomes a gyro, with a certain spin speed to make the fly, but, as I stated, heavier bullets are usually longer than lighter bullets of the same shape.

Sorry....but I didn't reiterate what you said. And I fully understand what a VLD is.

The part you are missing is that because of their overall longer length, a VLD requires a fast twist barrel. Yet, contrary to what you are saying, a VLD has a very short bearing surface in comparison to a normal bullet of the same diameter that is not nearly as long in overall length.

As a result, again....bearing surface on the bullet (the amount of the bullet touching the barrel has nothing to do with barrel twist.

The overall length of the bullet (the gyro) determines required barrel twist. Because a gyro spins around its center of gravity (its balance point) when released freely into the atmosphere, it could care less where or how long the bearing surface was which imparted the spin it is now experiencing. It will spin evenly around its center of gravity in the atmosphere if there has been enough spin induced to support its overall length. If not the bullet will not be stable.....just like a top spinning too slowly wobbles.

For simplification, a bullet's center of gravity is the balance point of the bullet. If you very carefully put the bullet on a razors edge at the exact center of gravity, it would in theory balance and just sit there, stable.

Wizwaldo: I agree 100% with your statement that a bullet cannot be overstabilized....

-BCB