Superformance GMX, not impressed Update: recovered one

I used Nosler E-Tips again this year with good success. Very limited meat loss too. Pushed these 180 grains in the 300 Wby to about 3100 fps. Estimated impact velocity about 2800 fps. The flattened slug hit the front shoulder of the moose and was recovered under the skin on the opposite side. Where it hit bone, there was a bit of a mess, but still very good recovery.

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GMX is hardly a fragile bullet. I bet if you do a search you could find a thread about them not expanding and penciling through...lol I'd bet there was no fragmentation in this example. Just the result of a mass moving through a deer. You can't judge bullet performance on one experience....there's way too many variables. From the testing in ballistic medium that I've done, I'd say the GMX and the TSX offer pretty similar performance and they should because construction wise they are pretty similar.

To the OP, I doubt you'd have seen anything much different with any bullet...btw, good shooting.

Agreed on all points. Perhaps the answer lies in the heart, as the OP relates that the heart exploded. I recall Kevin (Daktari) Robertson opined that a game animal drops much quicker if the top of the heart was hit with an expanding bullet just when it was about to pump. At this moment the heart is engorged with blood, and the bullet impact into a large volume of fluid would be much more dramatic than be the case a moment later. When I get home I'll have to see if I can find the exact passage and see if it is relevant to this particular incident.
 
Thanks for posting - I've been curious about the GMX performance for awhile. Bass Pro seems to be perpetually sold out around here, so I've opted for the 140BTSP's instead. Both seem quite fast, though...
 
If you hit ribs in and ribs out you would have the "blood pooling" in that layer of fat on the out side of the ribs. There's not really a lot of meat to wreck there. If you hit a shoulder, and the big bone going through you'd be out some meat for sure, but I don't really see the problem here.

Over the years I've personally found that the "premium" bullets are more trouble than they're worth. I use the run of the mill Hornadys and Speers.
 
Long story, but I ended up shooting a doe lengthwise with this 139 GMX suprformance load. I didn't chrony it, but the impact velocity would have been in the 3000+fps range.

After travelling in a straight line through about 3 feet of deer, it almost, but didn't quite make it through the skin on the front shoulder of the animal. It doesn't appear to have hit any bone, although I haven't started processing the animal at all, other than field dressing and skinning it. It seems to be pretty much identical to the performance I'd expect from a TSX under these conditions - it opens quickly, but not as quickly as a ballistic tip or SST. Meat damage is nowhere near what the OP has, but that's probably all down to difference in shot placement.

Anyway, I'm pleased overall with this bullet. I'd have no reservations about trying a quartering shot on a moose or elk based on what I've seen so far.

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Just a quick update. I killed two does today at 250 yards. Saw the first one crossing the power line, killed it (broadside) and a bedded doe stood up 10 yards from the one I just shot. It was facing my way and I killed the one too. Broadside doe didn't have much bloodshot meat. Doe facing me I shot straight on. Bullet exited at the hip joint. Everything inside was destroyed. Nasty cleanup, stomach contents everywhere. Not much bloodshot in the hip.

I will keep using these. They shoot good, cheaper than ttsx and have higher bc.

Cheers
 
Bullet does what its supposed to do,you pick the yardage and shot placement.I just find them light for caliber,but they certainly retain weight,from what I have read .I havent recovered one yet.
 
Update

I cut up the deer today and upon closer inspection it seems I was incorrect yesterday. The bullet did not exit in the rear as I thought yesterday. It exited just infront of the rear leg, turned sideways it seems (petals pushed back up) and I found this bullet inside the top round muscle sideways. It weighs 134.4gr.

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hmm - compared to the photos on Hornady's site, that looks pretty similar to the '2700 fps impact' picture. It's quite a bit less expanded than mine, which was at a much closer range (95 yards lasered).

Interesting - this bullet seems most at home in Magnum applications; I definitely would not trust this bullet in lower velocity cartridges
 
Update

I cut up the deer today and upon closer inspection it seems I was incorrect yesterday. The bullet did not exit in the rear as I thought yesterday. It exited just infront of the rear leg, turned sideways it seems (petals pushed back up) and I found this bullet inside the top round muscle sideways. It weighs 134.4gr.

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That looks like perfect perfomance and great penetration. I love this bullet in my 7/08!
 
hmm - compared to the photos on Hornady's site, that looks pretty similar to the '2700 fps impact' picture. It's quite a bit less expanded than mine, which was at a much closer range (95 yards lasered).

Interesting - this bullet seems most at home in Magnum applications; I definitely would not trust this bullet in lower velocity cartridges

Impact speed was ~2600fps at 250 yards. I agree the monos are best when pushed fast. If I am lucky I may go moose huntig this year yet. I will be using these.
 
That doesn't look bad compared to shooting Berger's.... you have potential for lots of meat loss with those, from the 5 deer I have shot with those the only direction a deer does is straight down. I had a GMX load for elk this year but have not been able to use it yet. We have shot ballistic gelatin with a 300 Weatherby and 165 GMX's at at 100 yds our 28" block could not stop it.
 
I've seen some magzine reviews, and it seems like you need a little more than 35" of gelatin to stop the GMX. Pretty consistent with my experience - it took about 3' of soft deer parts (no bones struck) to stop mine
 
I just shot another whitetail with the 139 GMX. A little buck, at 250 yards. It was quartering toward me, and I drilled one right into the front shoulder. It struck and shattered the socket, which mangled the shoulder pretty good but nothing at all like your first pics above. Much of the meat damaged by bone fragments is shredded, but not bloodshot.

Despite smashing through the biggest bone structure on the front of a deer, the bullet continued in a laser-straight line, taking out a rib, demolishing a lung, disconnecting all the plumbing on the top of the heart, poking a hole in the liver, then going through some of the guts, finally exiting the paunch just in front of the rear quarter. A good 2 to 3 feet of deer penetration overall, and the bullet was not recovered. Too bad, by the looks of it, it only *barely* made it out.

Needless to say, the deer didn't make it very far. It flopped around, gave the 'heart-shot kick,' and bolted into the trees, only making it a few steps into the bush before collapsing. Maybe ten or twenty yards, tops. Good solid blood trail to follow, recovery was a piece of cake.

One of my hunting partners, a little over a mile away, said that the meaty 'thwop' of bullet impact and expansion was about as loud as the muzzle blast was. I don't remember, I knew the deer was dead on its feet before that sound would have gotten back to me.

Unfortunately, this deer was a solid hour's hike in down some overgrown cutlines; it was good exercise dragging this bad boy out of there.

Anyway, I'm completely confident in taking this bullet and this load out elk and moose hunting based on what I've seen so far.
 
Here's a 139 grain GMX fired from a 7mm at about 150 yards. It literally went stem to stern and encounterd a lot of big bone on the trip. I'm convinced.

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