Thoughts on 150 gr TTSX performance in 7mm WBY MAG

[Spotter's Signature]

Greetings,

I thought about posting this for a while. The reason is, I had difficulty finding detailed data on 7mm WBY MAG, for loads I was interested in. Maybe this post will help somebody in their load development, or research on hunting cartridge performance. This will compliment what was written here in different posts, regarding the 7mm 150 gr TTSX.
I decided to 100% switch to copper bullets this season, to give them a try for the first time. I picked the 150 gr TTSX for my Mark V. Reasons: good BC (for copper), I can shoot it fast, great terminal performance and precision/accuracy, variety of distances covered, and what others said - load development is easy.
To add to what was posted here a while back on velocities required to open those projectiles, I called Barnes - their technician said that the 7mm 150 gr TTSX projectile opens at 1500 fps to expand to 1.5 x diameter, and it needs 1700 fps to open fully as designed, to 2 x the diameter. These are fantastic numbers, if they work in reality. I need your input on it; there's so much arguing about these bullets!

Here's the load (my max!) - FOLLOW OFFICIAL MANUFACTURER'S SUGGESTIONS AND WORK CAUTIOUSLY UP TO YOUR PRECISION LOAD!

Weatherby Mark V 1:10"
24" (cut) pencil barrel with Gen 3 Micro Bastard
150 gr TTSX
Peterson Brass
CCI 250
78.4 gr Ramshot Magnum
BTO: 2.705"
M.V. 3192 fps

First 4 shots: 0.300 MOA, including the 5th (hot skinny barrel "walks"): 0.779 MOA. I just noticed a typo - 78.4 gr NOT 77.4 gr of powder.


Harvest report:
1st day of the rifle season - great 8 point WT buck, angled heart shot (quartering away), ~75 yds. He went ~50 yds before collapsing.


Golf ball size exit:


Doe #1: 115 yds, struck by a lightning. First time I saw this kind of blowback at the entry wound. Pass through; small exit. 100% as advertised.


I found the bullet some 5 yds away after looking; this part is also interesting to me. It dug into the ground about 7" after passing through the doe. 90% weight retention.


Doe #2: 230 yds. Walked ~15 yds before collapsing. Broadside heart shot.
Golf ball size exit:


Now, the other part...

Doe #3: 253 yds. Slightly quartering away, lung shot. She pivoted after the hit and collapsed, all in less than a second. I found the entry wound after looking for it. No exit. Outside, she looked undamaged. Inside, probably everything was destroyed. But now - if she ran and I were to track her, I would likely not find her. Impact velocity: 2654 fps.
That's all I saw; not a droplet of blood:


So, why all this on a long range forum? I was testing these bullets to build up confidence in them BEFORE I go on some long range hunt of a lifetime. Hunting with ammo that you have no FULL confidence in ruins any hunting experience.
When designing this load I had an 800 yds elk load in mind. I did my part, here are the ballistics of the finished ammo.



So, on paper this works comfortably to 700 yds and I'd take game with full conviction within 500 yards with these bullets. However, after that last doe my conviction got a bit eroded; this was at 253 yds!
I'm a long range shooter, my equipment works very well, it's just the terminal ballistics at a distance (well within the "expansion velocity"!) that now occupy my mind. My Mark V cannot take long bullets, and the jump is Weatherby-huge, which limits my options (secant ogives), but that is not really a problem.
So much has been already written about it; so much of it is splitting hairs... TSX vs TTSX vs LRX vs Hammers vs CX vs E-Tips and a number of others that people swear by... How to find confidence in any of this?
I have one more tag this season, for a buck. If I harvest another I'll report more on how these bullets work for me, if I find anything interesting. I want to sort it all out soon, and then make decisions whether to stick with these as a universal load for 0-700 yds, or go back to lead/copper bullets. Interbonds, Accubonds, Partitions, ELD-X (surprising) all work well. ABLRs work OK.

Wow, this post got long. I hope somebody will find it useful. Thank you all for sharing your knowledge.

Merry Christmas to all of you! Stay safe and happy hunting.

SS

 

[MtPockets]

Thank you for posting this. I'm looking for the "perfect" bullet for a 7 RUM, so this helps a bunch.

 

[jjmp]

You're well on your way,far better to test and prove it to yourself. Scratch #3 doe when she turned so did the bullet,and tumbled. Factory's very slow to change ? Because they think it's right their way . Custom smith's can help . Elk are 5 x the size of our deer . The best bullets evolve and are always improving. My Cartridge was the 7 STW ,shot 160 partitions to 1,000 yds , also hampered with a slow factory twist , sound familiar, but it worked fine. Enjoy the ride & thks for posting . Cheers

 

[Koda_]

Id put more weight on the fact you got a true bang-flop than worry about an exit hole on only one data point... bullets can do weird things. Your getting near 3200fps from a 150gn bullet that you've proven to turn insides into soup... go hunt elk with confidence.

 

[MagnumManiac]

I can't fault them, I used them in my STW and found them a little light, was also using the Nosler 150g Ballistic Tip and found the 160/168g class of bullets to be ideal.
I also used the 150g TTSX, 165g TTSX and 180g TTSX in my 300RUM and was happy with all of them in performance on game as well as accuracy. The 165g put 10 rounds into sub MoA, so that impressed me too. Barnes have been easier to find here too, and normally I'm a through and through bonded bullet guy…not anymore!

Cheers.

 

[JamesWilson5]

Thank you for posting this. I'm looking for the "perfect" bullet for a 7 RUM, so this helps a bunch.

I have a great load for 150 ttsx in the rum but it's hot

 

[JamesWilson5]

Barnes bullets and every other copper bullet speed is the key I would either increase velocity or drop bullet weight and still increase velocity

 

[mnoland30]

I shot my first bull with a Barnes X 140 gr. in a 7 Rem Mag at around 250 yards. He only went 35 yards, but there was no blood and no exit. I switched to 160 gr., and I've liked the results much better. I believe a higher sectional density is better for elk. The 168 LRX bullets have a high B.C. and deliver more energy at long range. I haven't tried them yet, I'm still shooting my stock of 160 gr. blue bullets.

I started using Barnes because my butcher used to put all the recovered bullets in a tray on the counter. The Barnes all looked exactly like the advertisements.

 

[Laelkhunter]

Remember the rule of thumb for monolithics. Reduce the bullet weight 10% from what you are using in cup & core. In my .30 cal, I went from 180 (Nosler Partition) to 168 TTSX, and in my .340 Wby, I went from 250 (Nosler Partition) to the 225 TTSX. When doing so, the velocities increased which is the key for getting performance on game from the all copper bullets. Accuracy for the Barnes TTSX has been excellent in all rifles I have shot them out of. Better than the Nosler Partition.
It's difficult for some old timers that have "always used a heavy bullet" to change their ways and use a lighter bullet in their rifle.

 

[Philward]

I shot my first bull with a Barnes X 140 gr. in a 7 Rem Mag at around 250 yards. He only went 35 yards, but there was no blood and no exit. I switched to 160 gr., and I've liked the results much better. I believe a higher sectional density is better for elk. The 168 LRX bullets have a high B.C. and deliver more energy at long range. I haven't tried them yet, I'm still shooting my stock of 160 gr. blue bullets.

I started using Barnes because my butcher used to put all the recovered bullets in a tray on the counter. The Barnes all looked exactly like the advertisements.

I still have a few of those blue bullets too, from back in 2005 or so. Shot one deer and one cow elk using them and they worked fine.

 

[esshup]

Spotter's Signature, a buddy developed a load for his friends 7mm Rem Mag using the 139g Barnes TTSX bullets. I don't want to post the load here because it's considerably hotter than what the book says. His friend took a 380 class bull Elk at 540 yds with it and it didn't go 20 yds, and was a pass through. He said it was a laser out to 400 yds.

Like you, I go monolithic bullets when shooting something fast and I have no idea whether the animal will be near or far. I use the 85g Barnes in my .243, I have shot a Wi buck at 20 yds. Deer facing me, head down. Bullet entered top of neck/shoulder junction, I thought great, now I will finally recover a Barnes bullet. Nope, it exited the scrotum. Bang flop, but needless to say it was a mess inside.

I'm going to use the 132g HHT Hammer bullet in a buddies 7mm Rem Mag for an elk hunt he's going on. They said to use RL-26 powder and I found 4# at a local gun shop, so we are set. He bought Peterson brass. This is for next year, so we have a bit of time..

Great bullet test that you did, and since it was only 1 bullet that you saw that didn't perform like you wanted (but still smoked the deer), I wouldn't worry about it. Did you recover that bullet? What did it look like?

 

[Spotter's Signature]

Thank you for posting this. I'm looking for the "perfect" bullet for a 7 RUM, so this helps a bunch.

Please, let us know here what you settle for. And why!

 

[BPollard]

You get a little advantage with the tip triple shock. But if you want to seat them out a little further, try 150 triple shock. I shoot it out of my 300 Weatherby with a custom load and. I am able to seat them out a little further and still fit in the magazine. that load has five elk on it and many other animals. my furthest shot was at 603yds in Colorado in 2017.the next day my buddy used it at 73yds. Both elk down right there.

 

[Spotter's Signature]

My Cartridge was the 7 STW ,shot 160 partitions to 1,000 yds , also hampered with a slow factory twist , sound familiar...

What velocities were you getting in your 7 STW with the partitions? 1000 yds is a lot of land to cover with this bullet. I limited my 160s to ~500 yds effective range; the only precision load I developed in my Mark V was only 3000 fps. Every partition I used before was effective, though. The thing is, I wanted to step away from lead, stretch the distance and target penetration on larger animals that Barnes bullets are known for.