7mm-08 139 GMX or 120 TTSX

[brsnow]

Currently use superformance 139 GMX, it shoots fine. The 120 Barnes TTSX ammo is slightly more accurate. These are out of my Kimber Montana which I use for elk. I keep shots to a maximum 400 yards, but am unsure on how the 120 grain would perform on Elk. Anyone have experience with it? Appreciate the help.

 

[HiMtnHntr]

Why not go 140 ttsx, or 139 or 145 lrx? The 139 lrx shoot well out of my 08...

 

[brsnow]

Why not go 140 ttsx, or 139 or 145 lrx? The 139 lrx shoot well out of my 08...

Thanks, I don’t reload so just have factory ammo and need to stay lead free. GMX are right around 1” moa and worked fine on elk so far, the 120 ttsx cloverleafs even with my shooting

 

[vermeire]

It's been a while since I researched weights for my 7-08 but I decided on 140s. In general they have better BC and sectional density while maintaining reasonable velocity. If the 139s shoot well I'd stick with them especially for elk. Don't mess with what works!

 

[doverpack12]

Currently use superformance 139 GMX, it shoots fine. The 120 Barnes TTSX ammo is slightly more accurate. These are out of my Kimber Montana which I use for elk. I keep shots to a maximum 400 yards, but am unsure on how the 120 grain would perform on Elk. Anyone have experience with it? Appreciate the help.

You need to test actual muzzle velocities and compare to the box and put them into an app to see what your downrange speed will be. My opinion is the 139 is too heavy to shoot beyond 300 and when you look at the "claimed" 400 yard velocity (pretty sure you won't hit that muzzle velocity so it will be slower) you will BARELY open that GMX as in my experience they require the most speed of all the monos to open and 2189 fps is cutting it too close and I would stay above 2300 for good performance. Heavy monos and smaller powder capacity chamberings just don't work that well at any amount of distance. That 120 will outperform the 139 strictly based on velocity alone. Velocity is paramount with monolithic bullets and I wish manufacturers would stop pushing the weight and chase speed instead.

 

[HiMtnHntr]

Maybe look at some nosler factory ammo in 140, partition or accubond.

 

[brsnow]

You need to test actual muzzle velocities and compare to the box and put them into an app to see what your downrange speed will be. My opinion is the 139 is too heavy to shoot beyond 300 and when you look at the "claimed" 400 yard velocity (pretty sure you won't hit that muzzle velocity so it will be slower) you will BARELY open that GMX as in my experience they require the most speed of all the monos to open and 2189 fps is cutting it too close and I would stay above 2300 for good performance. Heavy monos and smaller powder capacity chamberings just don't work that well at any amount of distance. That 120 will outperform the 139 strictly based on velocity alone. Velocity is paramount with monolithic bullets and I wish manufacturers would stop pushing the weight and chase speed instead.

The muzzle velocity on the 139 GMX was 3 shot average of 2904 in Denver area. I am also much higher and colder during the season. I have not recovered them as I do the gutless method but they haven’t failed.

 

[steelheadmike]

I used the federal trophy copper 140gr in 7-08 last year on a couple deer with excellent results. Never recovered a bullet but the wound channels were devastating. Turned the lungs into goo.

 

[oenanthe]

I like the 140 TSX in my 7mm-08.

Federal makes Premium ammo with the 140 TSX: https://www.federalpremium.com/products/rifle/premium-centerfire-rifle/barnes-tsx/p708c

 

[MattB]

You need to test actual muzzle velocities and compare to the box and put them into an app to see what your downrange speed will be. My opinion is the 139 is too heavy to shoot beyond 300 and when you look at the "claimed" 400 yard velocity (pretty sure you won't hit that muzzle velocity so it will be slower) you will BARELY open that GMX as in my experience they require the most speed of all the monos to open and 2189 fps is cutting it too close and I would stay above 2300 for good performance. Heavy monos and smaller powder capacity chamberings just don't work that well at any amount of distance. That 120 will outperform the 139 strictly based on velocity alone. Velocity is paramount with monolithic bullets and I wish manufacturers would stop pushing the weight and chase speed instead.

I haven't chrono'd them but when I was in that predicament and based on factory data I was shocked at how quickly the 120 Barnes bled speed compared to the 139 GMX due to the BC differentials. Not sure how that plays into the velocities required for expansion for each bullet type. Regardless of load, I figured my 7-08 was a 400 yard gun max.

 

[hooker]

120TTSX. Run 'em fast and lighter for caliber. Save the 140TTSX for a 7mm mag... 3000fps and that 120TTSX in a 7mm-08 is like a hot knife in butter.

 

[Newtosavage]

120TTSX. Run 'em fast and lighter for caliber. Save the 140TTSX for a 7mm mag... 3000fps and that 120TTSX in a 7mm-08 is like a hot knife in butter.

Do you have experience shooting elk with the 120 TTSX? I'd like to hear about it if so.

I've always been a heavy-for-caliber guy when it comes to hunting bullets, but I can be convinced to change if it meant shooting a mono that offers the same (or better) lethality. It's just hard to believe that light of a bullet will get the job done on such a large critter.

 

[WJS23]

139 GMX is all this rifle eats

 

[Formidilosus]

Do you have experience shooting elk with the 120 TTSX? I'd like to hear about it if so.

I've always been a heavy-for-caliber guy when it comes to hunting bullets, but I can be convinced to change if it meant shooting a mono that offers the same (or better) lethality. It's just hard to believe that light of a bullet will get the job done on such a large critter.

I’ve seen what a 120gr Barnes does to elk. It has no problem in killing. No mono would be my first choice as the wound channel is relatively narrow compared to other bullets, but they kill fine.

Between the two (120gr TTSX and 139gr GMX) the 120gr all day long. GMX’s need around 2,400 FPS to see what most would call good expansion, the TTSX will be about 2,200fps impact for the same.

 

[hooker]

6.5 and .260rem have both taken bulls and cows in my sons hands. Dirt naps. All big bodied Roosevelt elk. The most impressive a 120 TTSX outta a .260 rem on a giant lead cow at 250 yds. Giant bodied blacktail tails and black bears and bull elk taken in a 7mm-08. Just run 'em as fast as you can. The TTSX shoots great outta ever rifle I've tried them in. As good as it gets.

 

[Newtosavage]

I’ve seen what a 120gr Barnes does to elk. It has no problem in killing. No mono would be my first choice as the wound channel is relatively narrow compared to other bullets, but they kill fine.

Between the two (120gr TTSX and 139gr GMX) the 120gr all day long. GMX’s need around 2,400 FPS to see what most would call good expansion, the TTSX will be about 2,200fps impact for the same.

Just finished a ladder test of my first batch of 120 TTSX's in my Savage 7mm-08 and I'm impressed with their accuracy. Ended up at 42 grains of IMR 8208 XBR (I use 40g under 162 ELD-X in my Tikka and have an 8 lb. jug of it). At 42.4 grains I saw pressure signs. 42 grains grants me 3000 fps. and 3/4" initial groups with no seating depth tests - just loading them at 2.80" to start with.

Going to use them for all my whitetails this year and see how they do. I do like the fact they are lead-free because we eat everything I shoot.

 

[Kimber7man]

Don’t discount the E-tip. I used Nosler factory E-tip 140 grain in my 7mm08 last fall. Chrono’d 2,780 out of my 22.5” barrel. Shot my cow elk at 370 yards and bullet went through. Based on Ballistic AE it was at about 2,250 fps velocity and 1,570 fpe when it hit her.
It’s at 2,080 fps and 1,350 fpe at 500 yards.
I’m seriously considering taking it for bull elk this fall but bumping the velocity up 100 fps with handloads.

 

[Formidilosus]

Going to use them for all my whitetails this year and see how they do. I do like the fact they are lead-free because we eat everything I shoot.

We eat everything we kill as well. We consume red meat on average of 10-12 meals a week and have not bought beef in two years.

Not to go into a big discussion about the lead in meat deal- but it is a complete farce. Medically there is no risk to eating animals that were killed with lead bullets- none. Not for adults, not for children. That is not how lead works in the body. Lead styphenate from primers- yes in large doses. Lead particales in meat- no.


I work with heavy metals, have to get checked for lead toxicity multiple times a year due to the amount of ammo I shoot and the amount of time I spend in shoothouses, work with surgeons and doctors that have done work on this very subject, have a brief background in the medical field, and also had to deal with “lead bullets are bad” from the military. It is 100% an effort to ban common ammunition. It started in the military, and has transferred to the hunting world. Now, almost all of the funding and backing for the “lead in meat” campaign has roots back to anti hunting and anti-gun individuals and groups. Every single actual study has shown no correlation to lead toxicity and eating large amounts of game killed with lead bullets, quite the opposite actually. Also, the amount of lead and the distance it travels in animals has been purposefully fabricated to make it seem like it spreads much farther than it actually does.


I pay attention to, and probably care more about my blood toxicity levels than the vast majority of people and if there was even a tiny risk I would be using monos. There’s not. If someone wants to use monos, awesome. But don’t allow yourself to be lead down a path of red herrings.

 

[Rob5589]

Just finished a ladder test of my first batch of 120 TTSX's in my Savage 7mm-08 and I'm impressed with their accuracy. Ended up at 42 grains of IMR 8208 XBR (I use 40g under 162 ELD-X in my Tikka and have an 8 lb. jug of it). At 42.4 grains I saw pressure signs. 42 grains grants me 3000 fps. and 3/4" initial groups with no seating depth tests - just loading them at 2.80" to start with.

Going to use them for all my whitetails this year and see how they do. I do like the fact they are lead-free because we eat everything I shoot.

I found RL15 to give me the best over all results in my Tikka. 120 TTSX, 45'ish of RL15, 3150 fps, and 5/8 - 3/4" for 5 shots at 100. I run them at the standard length, didn't even mess with seating depths at all. Love that gun

 

[Newtosavage]

I found RL15 to give me the best over all results in my Tikka. 120 TTSX, 45'ish of RL15, 3150 fps, and 5/8 - 3/4" for 5 shots at 100. I run them at the standard length, didn't even mess with seating depths at all. Love that gun

If I didn't have about 6 lbs. of 8208 in my workshop, I'd be using Varget. Maybe someday I'll get there, but 3K is plenty of speed for the ranges I shoot whitetails.

Formid, no disrespect but I'll go with the peer-reviewed science just to stay on the safe side

Probably gonna switch from the 162 ELD-X to the 145 Barnes LR or 150 E-tip for my Tikka elk round next.

https://www.amjmed.com/article/S0002-9343(16)30021-3/pdf

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0015350

https://www.allaboutbirds.org/get-the-lead-out-the-poisoning-threat-from-tainted-hunting-carcasses/

https://www.wildlifecenter.org/sites/default/files/WCV-Position-on-Lead4.pdf

https://wildlife.org/wp-content/uploads/2017/11/112117_PS_LeadinAmmunitionandFishingTackle.pdf