7mm-08 Hornady Superformamce CX 139 gr. Question.

[mifune326]

Hi Everyone,

New guy to the Forum here. I have a factory ammo related question. While on a Whitetail hunt in Wyoming last month, I picked up a box of Hornady Superformance 139 gr. CX ammo for use in my 7mm-08 Tikka T3x (22" barrel). I normally run factory Barnes Vor-tx 120 gr. TTSX and have had great success with it. I'm interested in trying a heavier projectile for a possible future elk hunt.

Being partial to the monolithic projectiles, the Hornady CX appeared like a good possible option. Only thing is I can't seem to find any reviews or opinions on the web for this particular ammo. Has anyone used this ammo or have an opinion, good or bad? Thank you!

 

[LVJ76]

The Superformance ammo we have tried does not shoot well, does not group 1 MOA or better. First see if it shoots good or not, if it does, then see what speeds you get out of it.

 

[cape cove]

I can't give you a precise opinion on the ammo you ask of. But I have shot 139 gr GMX Hornady Superformance ammo in my Custom Kimber 7/08. I never tested the load for velocity only accuracy. I could get 3 shot groups of appx .3 with the smallest being .224. In all my 40 yrs of handloading it was the only factory ammo that I could not load as good as or better concerning accuracy. I even took a few rounds apart to get some details on the load but could never duplicate it's accuracy. I believe the CX ammo has replaced the older Superformance GMX line. JME

 

[mifune326]

Thank you fellas, I appreciate the info! I'll shoot it and see what kind of groups I get out of my T3x. Are there any other all copper factory loadings you could recommend, like maybe the Federal Premium 140g? What's the heaviest projectile you would go with considering the 1:9.25 barrel twist?

 

[KMLampson]

If you want to shoot copper, you're pretty limited with factory ammo. I wouldn't hesitate to use either the 139 gr CX or 140 gr Trophy copper if they group well. Copper bullets like speed, and with the 7-08 I don't feel it pushes 150 gr copper bullets fast enough.

 

[LVJ76]

Thank you fellas, I appreciate the info! I'll shoot it and see what kind of groups I get out of my T3x. Are there any other all copper factory loadings you could recommend, like maybe the Federal Premium 140g? What's the heaviest projectile you would go with considering the 1:9.25 barrel twist?

You can go up to 180gr with a 1 in 9:25, I shoot them out of my 7mm Rem Mag with no issues.

On my 7mm-08's I shoot 168gr Hybrids, 162gr AMax and SST, and 160gr TMK with no issues.

As far as monos maybe a 160gr, but too heavy for this cartridge considering they need speed to expand correctly. Personally if I had to use a mono, with this cartridge I would not go higher than a 120gr bulllet.bullet, but that's just me.

 

[cabelasken]

I took a cow elk and mule deer buck this year with 130 Absolute Hammers out of a 280 Ackley at 3285 muzzle velocity and it performed flawlessly. I have two 7-08 that i want to try the Hammers in and expect the muzzle velocity to be above 3100. My 7-08s have shot well with the Barnes 120 TTSX bullets and I'm getting 3100 FPS with them. All of these bullets will be adequate for elk at these velocities given reasonable target distances.

 

[Tom Erickson]

Hi Everyone,

New guy to the Forum here. I have a factory ammo related question. While on a Whitetail hunt in Wyoming last month, I picked up a box of Hornady Superformance 139 gr. CX ammo for use in my 7mm-08 Tikka T3x (22" barrel). I normally run factory Barnes Vor-tx 120 gr. TTSX and have had great success with it. I'm interested in trying a heavier projectile for a possible future elk hunt.

Being partial to the monolithic projectiles, the Hornady CX appeared like a good possible option. Only thing is I can't seem to find any reviews or opinions on the web for this particular ammo. Has anyone used this ammo or have an opinion, good or bad? Thank you!

Have you thought about reloading? Barns makes a 168 grain long range in the .284 I'm going to load up some barns 140 grain for my 7mm-08 for next year

 

[LVJ76]

Have you thought about reloading? Barns makes a 168 grain long range in the .284 I'm going to load up some barns 140 grain for my 7mm-08 for next year

What twist rate is required for this 168g bullet? just curious, thanks.

@mifune326 I forgot to ask, up to what distances will you be shooting at elk? A 139gr/140gr bullet from Factory ammo will provably be between 2,700 and 2,800 fps, and I believe these work best at impact velocities above 2,000 fps.

@cabelasken makes a good point with the 120gr bullet, you can push it faster and they don't shed weight, so you don't need a heavier bullet.

 

[cabelasken]

I've found with mono copper that the faster you drive them to get the impact velocity up, the better they perform. Even though they expand at velocities below 2000 fps, the terminal performance may not be what you expect. I limit my shots to where I know my impact velocity is above 2400 fps when I use mono copper. I know this is conservative, but that's just me.

 

[FEENIX]

Hi Everyone,

New guy to the Forum here. I have a factory ammo related question. While on a Whitetail hunt in Wyoming last month, I picked up a box of Hornady Superformance 139 gr. CX ammo for use in my 7mm-08 Tikka T3x (22" barrel). I normally run factory Barnes Vor-tx 120 gr. TTSX and have had great success with it. I'm interested in trying a heavier projectile for a possible future elk hunt.

Being partial to the monolithic projectiles, the Hornady CX appeared like a good possible option. Only thing is I can't seem to find any reviews or opinions on the web for this particular ammo. Has anyone used this ammo or have an opinion, good or bad? Thank you!

I am sure there are others, but here are options on factory-loaded lead-free ammo:

Barnes: VOR-TX 120g TTSX BT

Copper Creek (https://coppercreekcartridgeco.com/product-category/ammunition/708rem/usage-copper/): 120/140/150 TTSX, 139/145/168 LRX; 150 CX

Federal: 140g Trophy copper

Hornady: 139g GMX/CX

Nosler:140g expansion tip (Etip)

Underwood: 142g controlled chaos

Winchester: 140g power core


Good luck!
Ed

 

[mifune326]

Thanks for all the awesome info everyone! Lots of help! The farthest shot that I would feel comfortable with would be somewhere in the area of 500 yds. LV.

And I totally agree Tom, I need to start reloading.

 

[cape cove]

What twist rate is required for this 168g bullet? just curious, thanks.

I have tried them in my 1/9.25 (7/08) and they were unstable. I believe Barnes recommends a 1/8 for the 168 LRX.

 

[cabelasken]

Have you thought about reloading? Barns makes a 168 grain long range in the .284 I'm going to load up some barns 140 grain for my 7mm-08 for next year

They also have a 145 Gr LRX that does a good job on elk. I took two with that bullet last year. Wound channel was perfect on two broadside shots. One at 420 yds and the other at 100 yds.