Home Forums Hunting & Shooting Ask The Gunwriters Two Tipped TSX's recovered in a row

This would theoretically have the opposite effect to what is observed- the mono would travel farther forward while maintaining rotational speed, while the C&C would keep spinning but slow its forward motion, showing an increase in twist as it progresses through the media.

Something else must be at play here. Perhaps the propeller effect John mentioned.

Jordan, whatever....

I understand the bullet maintaining its rate of spin, but have to admit I don't understand at all how the bullet gains RPM's as it meets the resistances of bone and flesh in a BG animal. You would think the increased resistance would work to slow everything down,not speed it up.... But we know it keeps spinning regardless.

The barnes does not have the big frontal area of some expanding bullets and the space between the expanding petals offers less resistance which is another reason I think it maintains forward velocity better.

How does the C&C gain rpm's as it's passing through the medium? It's losing weight and tearing itself apart...I have to admit I don't get it.

I would guess it appears to speed up RPMs because theoretically, as with air, the bullet is slowing up faster in flesh than it is losing RPMs.

Hi Bob,

Both forward velocity and rotational velocity start to slow down as soon as the bullet leaves the muzzle, it's just that the forward velocity decelerates at a much higher rate than the rotational velocity, especially once the bullet impacts the animal or media.

We're also adding some confusion to the mix by interchanging the term RPM (revolutions per minute, which starts to decrease slowly as soon as the bullet leaves the muzzle), and revolutions per inch, which starts to increase as soon as the bullet leaves the muzzle. Even if the bullet's rate of rotation stayed completely constant as the bullet penetrated, we would see the RPI increase as the bullet moves forward, since the forward motion is decelerating, meaning that the bullet continues to spin at the same rate, but it isn't travelling forward as fast.

Reading the propeller theory line made me frown and shake my head... Then I grabbed a few expended X bullets and looked carefully... Several things surprised me.

The bullets mostly came from a jug at the Barnes booth at SHOT, BTW.

First, the petals at final resting position are actually riding with the leading edge slightly forward on almost all of them! I would have expected the opposite due to the way they are bent back to trail both forward and rotational motion.

Second, the combination of large frontal area and the petals sticking out probably develops significant lift due to the reduced area on the back sides of the petals.

Third, the petals flatten on the former outside surface creating a ridge or hump on almost all of the petals, again, increasing the surface area of the top of the produced propeller compared to the lower surface.

It seems doable...

All I know is that when you track a bullet out across the frozen expanse of parts of the Bering Sea, the initial skip marks will be in a relatively straight line, but arc toward the right the farther you go, the arc becoming more pronounced as you approach the final resting place of the bullet.

This is a very interesting thread.

When selecting boolits for my recent elk hunt I switched midstream from the 160 gr TTSX to the 160 partition. Rifle is a 7x57. I polled some people who know what they are talking about and they mentioned the lower velocity of the 7 mauser possibly not expanding the TTSX when shooting heavy for caliber slugs. The partition sure did the trick traveling through a cow at 120 yards and blowing the heart up. Left a nice hole on it's way out as well.

That said, I live in California so I will need to find a good mono copper boolit for my rifle to hunt in state. Its been suggested that dropping to a 140 grain is the ticket when shooting the TTSX.

Would I have less concern about shooting the 160s (which my rifle likes) if I used the new plastic tip TTSX?

Thanks for any thoughts.

Also - knowing a fair bit about airplanes and propellers I'm not sure I can see a bullet mushrooming into a reliable airfoil after impact. There must be something else going on. There - now I've stirred the pot a little.

Jeff

Jordan I think I get it. I understand the benefits of the fast twist and have bullets here recovered from game that show it up pretty clearly. But the nuances of what goes on exactly(like this), is let on me....

Is this anything like a figure skater who builds momentum and then spins faster as she(he) tucks the arms closer to the body? I know it's different but maybe the analogy is helpful in trying to understand.

I always thought there must be an awful lot of pent up force in anything spinning at 200-250,000 rpm...it would pop your brains out your ears .

I don't understand it either. How about this BobinNH?

Shoot $hit and it falls over...

When all else fails....

belly deep yeah drive them fast and twist them hard and everything works out!


Tough to prove a negative and no sense worrying about what might have happened if you didn't, right?

Paradiddle:

I used to shoot 160 partitions in my .280, switched 2 years ago to 140 grain TTSX, couldn't be happier with change, four shots 4 deer, 2 dropped right there, 2 ran maybe 10m. Very little bloodshot meat. I liked the result so much that this year I have dropped down to 120 grain TTSX, haven't shot anything with this load yet but I am sure it is going to perform well.

Good to hear. Are you using the plastic tip TTSXs?

I have a couple 7x57s and a 7-08 with a lot of experience with the 120gr X, XBC, and TTSX. I do not go heavier even for big bull moose, caribou, or bears.

That is what he posted.

I've used the TSX for the last 7-8 years. I've yet to find one in a deer/antelope yet. Shots ranging from 20yds to 325yds on mule deer. No complaints. Just dead deer. Small hole in, small hole out, devastation in between. All shots from varying angles.

Is my thinking askew? I see the bullet not spinning stationary around an axis as much as an incline around an axis eg: a screw. So, if an animal is 18" thick a 12" twist rate bullet will rotate 1.5 revolutions passing through. If my thinking is anywhere correct the rotation will have only a small impact on tissue damage.

Seemingly. But perhaps the energy given off by the higher RPMs creates more of the effect than the bullet actually twisting?

Even 1.5 revolutions at 240,000 RPM would, as Bob pointed out, squeeze your brain out through your ears

Bob,

It's not that the bullet spins faster as it penetrates, but that the spinning continues as the forward motion slows down. Similar to the propeller on a boat. Picture the 'wound channel' in the water if a boat sat stationary with the propeller spinning. As the boat accelerates, the propeller starts out by spinning hundreds of times in the same place, to spinning 1 revolution every 1 foot of movement of the boat, and finally at top speed the boat travels 10 feet for every revolution of the prop. The wound channel in media would be a similar idea, only in reverse. The boat begins at top speed, and slowly comes to a stop while the propeller keeps spinning.

cavitation!

I killed lots of critters with the 140 XFB and never recovered one, but had plenty of instant tip-overs.



First time out with 120 TSX and TTSX and I wasn't so impressed. TTs seemed to work alright and expand well; not so with the T. (140s and 120s were all shot from the same rifle: 7mm-08.)

More to the point of this thread,



the first TTSX I ever fired was the 168 in 30-06 at over 200 yards. The chunk of spruce was the catch 'vehicle', assuming I hit the water-filled spaghetti bottle - which I did. Obviously, the 4-5" thickness of water affected the balance of the bullet as can be seen in the imprint it left on the wood.