Home Forums Hunting & Shooting General Big Game Minimum Velocity for TSX BT expansion

Been playing with a few of these in a neighbors stick... sorta growing on me.

I've yet to fully jump on the band wagon as the BC's are marginal for my style of hunting.

However, I would like real world data on the minimum velocity for reliable expansion of these pills...

TIA

Bear in mind, the BC's are calculated at 300yards according to Barnes website, not 100 yards like everyone else.

Here's some info from Barnes' Website:

http://www.barnesbullets.com/information/bullet-talk/x-citing-facts/

~JT

My longest real world info. You do the math. 338 Win mag started 2700ish, maybe 2720 IIRC but not 2750. 225 Barnes. Impact 2 times at 802 yds. Both had expansion, one was lungs/and part of liver due to angle, and second took spine out on caribou.

I shoot the pistol bullets in my 50 beowulf. They only start around 1600 fps or so IIRC, I've had definite expansion there at almost 200 yards.

Jeff

You were there when I killed the Antelope at 777 yards with the 300 win.and 180 TSX and the wound inside looked just like the one it at 280 yards every thing in it's path nothing but mush and the Lope went straight down.... For the 180 TSX I use a bc of .525 (this is higher than Barnes list) and the Exbal program plots the trajectory perfectly to 1100 yards as for as I have shot this combo.......

For those that question the BC issues, how do you come up with the new BC figures that are more correct than factory?

Jeff,when I started useing the TSX bullets for long range the only published bc value was for the old X bullets.I called Barnes and talked with them extensively about the correct bc for the 180 TSX,They had not shot the 180 TSX yet to establish the new bc<but stated that they were finding a 5 to 15 percnt reduction. I tried this approach and found that .525 matched my drop perfectly and when Barnes came out with the bc for the 180 it is slightly lower,but I found no reason to change......

jwp;

So, impact velocity out there via the 180 gr. TSX/.300WM would have been somewhere around 1800 fps?

According to my Exball program at 7400 feet of elevation it is close to 2000 FPS which was about the elevation of the hunt at sea level about 1800 FPS would be correct..........

Cool....

So, max range on my '06 would be 600+.... which considering the furthest I'd EVER shoot at a critter would be 600 (give or take, under perfect conditions), that'd work beautifully.

happy fathers day, Sean ...

And to you, buddy.

Just got off the phone with my little girl; not as good as holding her, but it'll do for today...

sorry to hear you don't have her with you today ... but thrilled to hear you got to hang out with her via phone ...

Posted by JonA in the Long Range Hunting Section

JonA
Campfire Regular


Registered: 12/09/04
Posts: 808
Loc: Everett, WA

Offline
Originally Posted By: JonA
...this thing doesn't come close to any of the curves--at least the way Sierra rates it. G5, G7, etc, it's way, way off from all of them. Not plus or minus a few percent throughout the velocity range as you would expect any bullet to be, but off 40%, 50%, 60%....! Somethin' just ain't right here.

I roughly sketched in what the portion of the drag curve, based upon their ratings, for that bullet would look like:



So either Sierra has invented a bullet that flies like no other projectile known to man (which would be amazing since it looks virtually identical to other 210s which are proven performers at long range) or their testing/rating of the BCs at various velocities was flawed.

I figured I should update this when I noticed Sierra has changed their ratings for the 210 SMK. They now rate it as:

.645 @ 1800 fps and above (Which means from the muzzle to about 1200 yds for me)

.630 between 1600 and 1800 fps
.600 between 1400 and 1600 fps
.530 @ 1400 fps and below

Compare their old rating (that made for the whacky curve above):

.620 @2500 fps and above
.575 between 2500 and 2200 fps
.490 between 2200 and 1950 fps
.425 between 1950 and 1700 fps
.375 @ 1700 fps and below

As you can see, this is a big improvement and if plotted on the graph above would come much closer to real drag curves (specifically the G5 and G7) than the whacky data they had before did.

So, they ended up a whopping .002 off from my data. And I don't even get paid for this stuff! But it's nice to see the change. I haven't yet tested myself, but have seen enough testimonials of this bullet (as well as the Berger 210 with very similar shape, etc) well beyond 1000 yds that show them doing very, very well.

However, I suspect the 208 A-Max is going to beat it by enough to make me lose interest in it. Maybe it's time for another drag race!
_________________________

so 1800 fps is the magic low number, ie: min. for expansion?

I surely don't know if the TSXs have improved on the old XFBs or not. In any case, they both suffer from the same criticism which has been leveled at the Hornady HP varmint bullets with their tiny tip opening; they may not open quickly and reliably on impact.

I was a proponent of the old X bullet design for quite a few years and used it on several dozen animals with very good results for the most part. I did have a cause for concern with a 6mm BT at long range once where I recovered the proof of non-expansion, something I had been suspicious of in the smaller bores. I kind of thought it was simply a smaller caliber problem. Then a few years ago, when I shot a moose which was a bit farther than I at first thought, it happened again, this time with a .338 diameter bullet. It turned out that the distance was around 495 meters (measured after the animal was killed, by GPS). That was a 225 XFB fired from a 340 Weatherby at between 2850-2900 fps. This is it:



The shot was taken at sea level so the air was denser, perhaps, than Barnes' ballistic expectations. Even so, the air was warm so temp was not a factor. If we use 2800 fps as the start velocity (even though those loads were above that) and we consider 495 meters to equal 600 yards (to be as pessimistic as possible), even then the estimated velocity is 1765 fps. I suspect it might easily have been higher than that. If not, then Barnes' estimates are rather optimistic. In any case, I still think the basic bullet design is a good one for high velocities and bone impacts. High velocities mean shorter distances which negates the need for superior accuracy. The old design was less expensive and worked fine for that. For longer distances I still trust lead cored types more. The jury is obviously still out, but I suspect Nosler may be onto the next "best" mono-metal bullet design with a polymer expansion "helper."

The TSX's definately open up better than the old X's based on what I've seen and recovered.

As to Barnes 1,800 fps number, I think that's the absolute bottom... I'd be more inclined to 2,000 fps. One of these days I'll shoot some phone books out at range w/ the TSX and see what's up.

So where did you hit the moose, if he was farther than you thought at 495 meters, as opposed to what? How far did you think he was? And at what angle was the shot to you? Where was the bullet located in the critter? In respect to point of aim? I'm alway curious about this sort of stuff. You recovered a bullet, that is always interesting to me.

Just wanted to say thanks for the question and all the answers people, I was wondering about the very same thing but hadn't gotten around to asking. you folks are awesome!

1800 is a steep order for what I do...

I like the results many are having with these bullets.. but in some of my situations the 1800 fps just isn't possible...

I do very much appreciate the input...