200+ Grain Bullets in 1:10 Twist .30 cal

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someguy2800 said:
Bullet length is also a factor in the twist rate required to stabilize a bullet. A 220 gr round nose is pretty stumpy compared to an ELD-X
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You didn't mention caliber, another factor in twist rate.
"Stumpy"? I suppose that's a matter of perception.
I honestly do not have - couldn't find anyway - a 220 grain round nose bullet to measure. However, my .308" bullet horde did turn up some heavy rounds. I had good results with a 225 grain Hornaday HPBT (of 1.580 inches length) fired using an M1917 barrel. No shot holes showed any hint of yaw.

The original question was 'will a .30 caliber 1:10 twist barrel stabilize a 200 or greater bullet?' I say yes and justify my answer. Do you have an actual rebuttal?
 
Varminterror said:
None of this is consistent with my experience.

Vitals on elk are massive, and they move and stop just like any other creature which walks the Earth. Yes, we need an animal to stay out for over a second for the bullet to reach them when we put that much air under them, but frankly, arrows need more time to reach 40 yards, but we don’t get this kind of complaint about common bowhunters as unethical due to time of flight.
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Really, an arrow shot from a modern compound bow take more than a second to reach 40 yards or 120 feet? That means that the arrow has to average less than 120 fps and since modern bows are launching arrows at 2x to 3x that speed the arrow would have to be slowing very rapidly and be traveling much less than 120 fps at impact in order for the average velocity to be 120 fps. I know you like data and fact based statements - do you have data to this effect? It's possibly true but seems very unlikely.

The calculator at this link suggests that it is extremely unlikely that it take an arrow more than a second to reach 40 yards.

http://www.bestcrossbowsource.com/crossbow-arrow-ballistics-calculator

I realize this is for crossbows, but an arrow is an arrow. Put in the correct values for a compound bow and arrow and this should be relatively accurate.
 
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Archie said:
The original .30 caliber rifle used by the United States was the .30-40 Krag. The standard ammunition shot a 220 grain FMJ bullet.
The second .30 caliber rifle used by the United States was the .30-03 Springfield and it fired the same (as far as I can tell) bullet with a different case.
Then in 1906, the round was changed by altering the case length (never can remember if it was longer or shorter, but not very much), the bullet was still the same diameter but weighed around 150 grains. Several changes of bullet weight occurred later an then the 7.62x51mm (.308 Winchester) was adopted.

The rifling twist has NEVER changed for issue rifles. Always has been 1:10 twist. I've tested a 225 grain expanding bullet and it works well. Theory and practice tend to agree.
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Sorry, no.

With the adoption of 7.62mm (M14, FAL, M60, M73, M240, G3, MG-3, etc) the standard twist was reduced to 1:12. And, incidentally the original M59 Ball bullet was quite a bit longer than the .30-06's M2 ball bullet, but about .02" shorter than M2 AP..

1:12 is good up to almost all 180 gr bullets above 2400 fps muzzle velocity. 1:10 is good for just about all available .30 caliber bullets.
 
someguy2800 said:
Bullet length is also a factor in the twist rate required to stabilize a bullet. A 220 gr round nose is pretty stumpy compared to an ELD-X
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citizenconn said:
Bingo. Give that man a ceegar.
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This is true, but there is also the factor that muzzle velocity plays a major parts as the RPM of the bullet is what provides stability, so even slow twists with sufficient velocity can achieve adequate stability.

Even a long ELD-X bullet will be stable with 1:10 if you keep the muzzle velocity up around 2200 fps.
 
Archie said:
You didn't mention caliber, another factor in twist rate.
"Stumpy"? I suppose that's a matter of perception.
I honestly do not have - couldn't find anyway - a 220 grain round nose bullet to measure. However, my .308" bullet horde did turn up some heavy rounds. I had good results with a 225 grain Hornaday HPBT (of 1.580 inches length) fired using an M1917 barrel. No shot holes showed any hint of yaw.

The original question was 'will a .30 caliber 1:10 twist barrel stabilize a 200 or greater bullet?' I say yes and justify my answer. Do you have an actual rebuttal?
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It’s not a personal attack, we are just having a discussion. I’m just adding to the conversation that weight is not the only factor and that just because you stabilize one bullet of a certain weight, it doesn’t mean you can stabilize all of them. This is for a 220gr Berger at 2400

4EF8DCB5-1B1C-4855-B8A7-C5F5BE256AD3.png
 
someguy2800 said:
It’s not a personal attack, we are just having a discussion. I’m just adding to the conversation that weight is not the only factor and that just because you stabilize one bullet of a certain weight, it doesn’t mean you can stabilize all of them. This is for a 220gr Berger at 2400
View attachment 1076270
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Okay, jumped too soon. Forgive me for assuming the worse. But I have a question: What the heck is "SG"?
 
lysanderxiii said:
This is true, but there is also the factor that muzzle velocity plays a major parts as the RPM of the bullet is what provides stability, so even slow twists with sufficient velocity can achieve adequate stability.

Even a long ELD-X bullet will be stable with 1:10 if you keep the muzzle velocity up around 2200 fps.
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Glad if it worked for you. It didn't work for me. Used a 69 grain HPBT in a .22-250 rifle. Shot pattern looked like a shotgun with buckshot from too far. From reading discussions of twist and bullet stability, extra velocity also increases the resistance from the air and has a higher tendency to make the bullet yaw.
 
1:10 30 cal will stabilize 220 grs even at modest velocities. The original 30-03 bullet was 220 grs and the even slower 30-40 Krag / 30 Army was a 220 cupronickel jacketed bullet at just about 2100 fps. I have run 215 grs lead in the 1:10 Krag at just under 2100 fps very consistently.
 
Thomasss said:
You really think you can hit the "boiler room" on a moving elk at 800 yards? MY brother has hunted elk in north eastern Colorado for over 30 years using a variety of guns including .270, 30.06 and 7mm mag.
His ammo was usually 130 grain SP Interlock or Core Lokt, With the .06 it was either 150 or 165 grain SP. His longest shot was 300 yards. He says an elk isn't any harder to put down than a white tail deer. The problem is they rarely stop moving and the "boiler room" is much smaller on an elk, needing a precision shot.
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I guess I’ve learned something new today. Your brother is hunting elk in Northeastern Colorado? Are you sure about that? I’m not saying there aren’t any elk in Northeastern Colorado but it sure as heck isn’t where you think about going to hunt elk in Colorado.

The boiler room on an elk is proportionally larger than on a deer, not smaller. We shoot a lot of elk in this family and seldom do we ever shoot a moving elk. They hold still just like any other animal.

If your brother is hunting an animal with a smaller boiler room than a deer and one that likes to move around a lot and he’s doing it in Northeastern Colorado are you sure he’s not talking about an antelope?
 
someguy2800 said:
It’s not a personal attack, we are just having a discussion. I’m just adding to the conversation that weight is not the only factor and that just because you stabilize one bullet of a certain weight, it doesn’t mean you can stabilize all of them. This is for a 220gr Berger at 2400

View attachment 1076270
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1.40 is still stable, in fact it's better than M193.

h5hK1D3.jpg
Archie said:
Glad if it worked for you. It didn't work for me. Used a 69 grain HPBT in a .22-250 rifle. Shot pattern looked like a shotgun with buckshot from too far. From reading discussions of twist and bullet stability, extra velocity also increases the resistance from the air and has a higher tendency to make the bullet yaw.
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Without knowing the twist, or the velocity of your 69 grainers, it is impossible to comment. However, it should be remembered that many things beside stability influence tight grouping, excessively high muzzle blast can destroy accuracy.
 
Thomasss said:
My error, he hunted in Steamboat Springs which is northwest of Denver.
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And you’re in error about the size of the boiler room on an elk and that they are always moving.

The boiler room on a bull elk is about twice the size of a whitetail deer and they move much like a mule deer. They don’t continuously run around all day, they move, they graze, they browse, they bed down, they sun themselves etc etc.. The last 5 elk we’ve killed in the last two years have been stationary for the shot.
 
Discussion is fun, but there's no need reinventing the wheel. .30 caliber cartridges such as the 30-40 Krag, .308 Winchester and 30-06 have been shooting 200+ gr. bullets out of 1-10" twist barrels for over a century and a quarter. I shoot a 1903, and 1917 and a couple of 1903A3's with a pointy cast bullet weighing around 210 grs. running 1400-1500 fps. Accuracy at 200 yds. is plenty good.

35W
 
H&Hhunter said:
The boiler room on an elk is proportionally larger than on a deer, not smaller. We shoot a lot of elk in this family and seldom do we ever shoot a moving elk. They hold still just like any other animal.
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Here his story guys. He hunted private property. The property was known for trophy bulls.
You were allowed to pick the animal you wanted. If wanted you could have a guide. BUT only that one animal was yours. If you shot too high in the chest, you could be tracking for a very long time. You might even lose it, and then you would be done, PERIOD! The safe shot was in or near the heart. I guess if you want take a 500 yard shot that would be up to you. According to Hornady a 500 yard ELDX shot has a bullet drop of 38.4 inches when zeroed at 200 yards with a muzzle velocity of 2860fps with a 24 inch barrel. I threw a few other numbers into their Ballistic computer too, like a minimum of 5,000 ft elevation shooting straight across with a temperature of 30 degrees F and a cross wind of 10mph and you said 2,700 fps at the muzzle.
Then the bullet will be dropping 42 or so inches with a wind drift of 12.2 inches. The average speed of a slow walking elk on even ground is 3.5 mph means he could travel 4 feet in .8 seconds. This all hypothetical. Going back to what my brother said as his max distance of 300 yards and bullet drop at the 2860 muzzle velocity with Hornady's tested numbers and bullet drop is about 7 inches. That's all I'm saying. With the cost of elk hunting these days, I like the 7 inch variable a lot!
 
Thomasss said:
Here his story guys. He hunted private property. The property was known for trophy bulls.
You were allowed to pick the animal you wanted. If wanted you could have a guide. BUT only that one animal was yours. If you shot too high in the chest, you could be tracking for a very long time. You might even lose it, and then you would be done, PERIOD! The safe shot was in or near the heart. I guess if you want take a 500 yard shot that would be up to you. According to Hornady a 500 yard ELDX shot has a bullet drop of 38.4 inches when zeroed at 200 yards with a muzzle velocity of 2860fps with a 24 inch barrel. I threw a few other numbers into their Ballistic computer too, like a minimum of 5,000 ft elevation shooting straight across with a temperature of 30 degrees F and a cross wind of 10mph and you said 2,700 fps at the muzzle.
Then the bullet will be dropping 42 or so inches with a wind drift of 12.2 inches. The average speed of a slow walking elk on even ground is 3.5 mph means he could travel 4 feet in .8 seconds. This all hypothetical. Going back to what my brother said as his max distance of 300 yards and bullet drop at the 2860 muzzle velocity with Hornady's tested numbers and bullet drop is about 7 inches. That's all I'm saying. With the cost of elk hunting these days, I like the 7 inch variable a lot!
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You are awfully hung up on the idea of shooting at a moving elk. Nobody else has advocated shooting at a moving target in this discussion. Can we please drop the notion that we are talking about shooting at a moving target at 500 yards?

At 2750 fps muzzle velocity, which is the actual number I put forward, not 2700, that 212 ELD-X is going to travel 500 yards in .64 seconds. 500 yards is an absolute chip shot for the 300 Win Mag or 300 PRC. The only possible variable would be a stiff wind and in that moment, a call would need to be made on whether a shot was made or further stalking was needed. This discussion is strictly about whether a 212 grain .30 cal bullet can be stabilized in a 1/10 twist, 22” barrel.​
 
35 Whelen said:
there's no need reinventing the wheel. .30 caliber cartridges such as the 30-40 Krag, .308 Winchester and 30-06 have been shooting 200+ gr. bullets out of 1-10" twist barrels for over a century and a quarter.
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Round nose and short ogive bullets are not the equal of long ogive VLD type bullets. It’s pretty easy to add a quarter inch of length to a 30 cal bullet in this weight class, the longer of which obviously requires greater spin stabilization than the shorter.
 
LoonWulf said:
RPMs are the end result, but generally velocities added effect are less important than twist, unless were talking the extreme ends of the spectrum......or at least thats what i understand.....
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Not really, the RPM of the bullet alone is the driver for stability. Usually, velocity is fixed by external factors, (maximum accuracy, maximum pressure, terminal effects, etc) so twist in the variable you get to play with.

With a 1-10 twist barrel, a bullet will spin up to 166,666 RPM at 2,500 fps and drops to 133,333 RPM at 2000 fps, with a 1-12 barrel in order to match RPMs you would need velocities of only 2,780 fps and 2,222 fps respectively. Compare:

1-12 @ 2,780 fps = 166,666 RPM
1-10 @ 2,500 fps = 166,666 RPM
1-12 @ 2,222 fps = 133,333 RPM
1-10 @ 2,000 fps = 133,333 RPM
1-12 @ 2,500 fps = 150,000 RPM
1-12 @ 2,000 fps = 120,000 RPM
 
The math is simple:

RPM = (MV in fps) / (Twist in inches per rev) * 720

720 is the combined conversion factor for 12 inches per foot and 60 seconds to 1 minute.

Eg: 3000fps / 10” per twist * 720 = 216krpm

Since the math is easy, the sensitivity analysis is also easy - how much does changing one or the other change the RPM’s?

The data @lysanderxiii posted is a prime example, even though he ignored that it proved the point he was trying to disprove. (However, he did mess up on some math - 2500 / 10 *720 is 180,000, not 166,000, 2780 /12 *720 = 166,800, not 166,666).

Changing twist rate influences velocity by the ratio of the inverses of the twists. We’re dividing by the inches per twist, which is the same as multiplying by the inverse - 10” on bottom of the formula is the same as .1 on top. So changing from 1:12” twist to 1:10” increases the RPM factor for a fixed velocity by 20%. (1/10)/(1/12) = 0.1/0.083333 = 1.2 —> 20% greater RPM.

What could you change about a load which would allow you to increase velocity by 20%?

So in practice, picking a barrel with a faster twist has the same influence as changing from a short action cartridge to a long action magnum… very fair to say that we have more control over RPM via twist rate than velocity - because we can move the needle farther with the same cartridge with twist than we can even dream of moving with velocity for a given bullet.
 
lysanderxiii said:
1-12 @ 2,780 fps = 166,666 RPM
1-10 @ 2,500 fps = 166,666 RPM
1-12 @ 2,222 fps = 133,333 RPM
1-10 @ 2,000 fps = 133,333 RPM
1-12 @ 2,500 fps = 150,000 RPM
1-12 @ 2,000 fps = 120,000 RPM
Click to expand...

I’m not sure what would have slipped in your calcs here, but most of this data is miscalculated, but especially the 1:10” data - the 1:12” data was either correct (2x) or close enough (within ~.1% 2x), but the 1:10” data is off by more than 10,000 rpm, so the apparent equivalencies displayed were false.

1-12 @ 2,780 fps = 166,800 RPM (off by 134)
1-10 @ 2,500 fps = 180,000 RPM (13,334)
1-12 @ 2,222 fps = 133,320 RPM (off by 13)
1-10 @ 2,000 fps = 144,000 RPM (10,667)
1-12 @ 2,500 fps = 150,000 RPM (correct)
1-12 @ 2,000 fps = 120,000 RPM (correct)
 
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