Looking for personal experience with GMX performance on elk

FrogFire7

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Location
Bradford County, Pennsylvania
Hi guys, here is my situation.

I'm from PA, and am planning to go west next fall for elk (first time). I have hunted whitetails for 20 years, and dabble in long range target and varmint shooting. I am a good shot under ideal conditions but have very little wind experience so that's a major limiting factor for me right now.

I ended up buying a savage lightweight rifle in 7mm-08, and was planning on using the 139 gmx Superformance factory ammo. I typically reload everything I have, but the Superformance is giving me 2900 fps so I may just stick with that for as little as I will shoot it (few shots for white tail a year).

My thought was that the GMX is supposed to expand reliably down to 2000 fps, and never come apart. My max range would be 500 yards based on impact velocity, but unless I do a lot more practice in the wind this year, my personal limit would probably be more like 300 if conditions weren't ideal.

I also see Hornady is making a 150 gmx now, not sure if the extra mass would offset the velocity difference. I guess seeing some of the recent threads on caliber size and bone penetration have me wondering if my rifle is capable at the ranges mentioned.

So, does anybody have experience with this bullet performance on elk? If possible, it would be nice to know if shots hit bone, what your range/velocity was, was the bullet recovered, etc.

I guess I'm not opposed to a different bullet either for the 7mm-08. I obviously have no elk experience but with the smaller caliber and slower velocity my thoughts are that penetration is paramount more than exploding a bullet in the vitals, school me if I'm wrong though, I'm an elk newb.

Again, personal or first hand experience with this caliber is preferred, but any gmx experience is welcome, as is experience with 7mm-08 on elk, with details.
 
I think you are right on track with thinking of a mono. At 500 the mass more than likely will not make a diffrence as the lighter one will still be faster. Usually over 500 yards the higher bc will start to overtake the lite flat one. At 300 it won't matter at all.
If you reload you should check out hammer bullets. You will have very limited time in load development under 20 rounds you will find a fast and accurate round. It's a mono like the gmx just a much better design imho.
 
Congrats on the new Savage. I just nabbed a Ruger American in 7mm-08 about an hour ago. The GMX is excellent on everything from pronghorn to elk, and I've used it with both standard and magnum calibers. Expands reliably and I can dial in accurate handloads rather easily. The Superformance stuff is great, as are most Hornady offerings and if they offer this in 150gn, it is more than adequate power and range for an elk. You are going to appreciate the weight of your short action when you're hiking at elevation, here in CO. Good luck
 
I have not. I actually just started loading them this fall. But Steve from hammer was spot on about the load work. It was the fastest load development I've done. Ed (zen archery) has taken a few hogs with them and said they were his new favorite. That bodes well because he kills lots of game every year. I will be going after thanksgiving after some larger Michigan whitetails so I'll be able to post results soon.
 
Congrats on the new Savage. I just nabbed a Ruger American in 7mm-08 about an hour ago. The GMX is excellent on everything from pronghorn to elk, and I've used it with both standard and magnum calibers. Expands reliably and I can dial in accurate handloads rather easily. The Superformance stuff is great, as are most Hornady offerings and if they offer this in 150gn, it is more than adequate power and range for an elk. You are going to appreciate the weight of your short action when you're hiking at elevation, here in CO. Good luck

Thanks Mike. Appreciate the kind words and advice
 
The bullet is usually as good the placement of the shot, load your bullets for your rifle and go out and play in the wind, take notes on "your" performance and you'll soon have a reasonable answer for what you and your gun are capable of regardless of the bullet loaded, which I'm sure you'll make a good decision on based on accuracy in your rifle, good luck, I live in southern ID and the wind it do blow
 
The bullet is usually as good the placement of the shot, load your bullets for your rifle and go out and play in the wind, take notes on "your" performance and you'll soon have a reasonable answer for what you and your gun are capable of regardless of the bullet loaded, which I'm sure you'll make a good decision on based on accuracy in your rifle, good luck, I live in southern ID and the wind it do blow

Thanks, I absolutely will limit myself to shots that I am confident will be kill shots. Wind is the limiting factor for me right now for sure (again, within my self imposed distance limits). That's just basic ethical hunting for me. And I do know that others have killed elk with less. :) I guess I'm just looking for reassurance from people who have used this combination (or others, but specifically in this caliber and velocity range) and how they have fared, especially if heavy bone was encountered. I do appreciate the kind words :)
 
I cook up a 130gn GMX 270Win load for my wife's Ruger 77. It shoots them so well we use this weight for both pronghorn and elk. In this shot, close to 3000fps at about 100 yards, it hit the front shoulder blew thru both lungs and exited the other shoulder. The cow went about 30 yards.
DSC01568 (2).JPG
 
My thought was that the GMX is supposed to expand reliably down to 2000 fps, and never come apart.

The Barnes 139 LRX has a minimum impact velocity of 1600fps, and like every other barnes will not come apart. Between myself, my son and my two hunting partners, we have shot over 150 critters with the barnes, moose, elk, muleys, whitetail, bears, african plains game, etc,etc......only ever recovered about 4 bullets. My son went through the brisket and had a complete north/south pass through on a decent bull elk using a 120 ttsx with a reduced load, MV 2600fps. Also took moose, muleys and black bears with this combo, your 7-08 with a 139 GMX or barnes TTSX/LRX will do just fine!

Not sayin the GMX isn't a fine bullet, as I have no personal experience with it, but the barnes certainly has a much longer history of performance.

Along with minimum impact velocity, keeping to 1000 ft/lbs and above at impact is a good idea for mono's to work their best!

Just my .02 cents
Good luck with your hunt!
Chris
 
Hi guys, here is my situation.

I'm from PA, and am planning to go west next fall for elk (first time). I have hunted whitetails for 20 years, and dabble in long range target and varmint shooting. I am a good shot under ideal conditions but have very little wind experience so that's a major limiting factor for me right now.

I ended up buying a savage lightweight rifle in 7mm-08, and was planning on using the 139 gmx Superformance factory ammo. I typically reload everything I have, but the Superformance is giving me 2900 fps so I may just stick with that for as little as I will shoot it (few shots for white tail a year).

My thought was that the GMX is supposed to expand reliably down to 2000 fps, and never come apart. My max range would be 500 yards based on impact velocity, but unless I do a lot more practice in the wind this year, my personal limit would probably be more like 300 if conditions weren't ideal.

I also see Hornady is making a 150 gmx now, not sure if the extra mass would offset the velocity difference. I guess seeing some of the recent threads on caliber size and bone penetration have me wondering if my rifle is capable at the ranges mentioned.

So, does anybody have experience with this bullet performance on elk? If possible, it would be nice to know if shots hit bone, what your range/velocity was, was the bullet recovered, etc.

I guess I'm not opposed to a different bullet either for the 7mm-08. I obviously have no elk experience but with the smaller caliber and slower velocity my thoughts are that penetration is paramount more than exploding a bullet in the vitals, school me if I'm wrong though, I'm an elk newb.

Again, personal or first hand experience with this caliber is preferred, but any gmx experience is welcome, as is experience with 7mm-08 on elk, with details.
I've shot some at both white tail and big boars and was not at all impressed with them, they didn't seem to expand much if any at all.

The most reliably performing mono's I've shot as far as consistent expansion goes are the Peregrine VLR series and the older plains master.

I've pretty much given up shooting lead core bullets at all as long as I can keep getting the Peregrines.

They have a new US distributor so it should be much easier to get them consistently. You can email Alliwyn in South Africa for his contact information. I'm not sure if they have a new US based website up and running yet.

https://www.peregrinemonolithics.com/rifle-reloading-bullets/
 
Thanks for chiming in guys. I like the lower impact velocity of the barnes, that might extend my effective range if I can get enough trigger time this summer. I'd have to check and see what the enervy levels are, that might be the range limiter (I have read around 1200 ft/lbs). I appreciate your input! :)
 
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