Has anybody had any luck with this bullet.? Last time I tried these I got like a 3" group in my 378 WBY.
As much as interlock bullets usually shoot lights out, these shoot horrible. Anyone??

Wondering the same, got some 80’s for the 6 ai, trade them out on the BT’s so I can hammer bulls.

I have tried the GMX in several weights and calibers and have yet to get acceptable results in the accuracy department

What is up with these slugs? Nothing like the TTSX!

They sure didn't work too well for me. Best I could get were 3 inch groups at 100 in my 8 twist 22-250.

I have tried the 110 grain GMX in my 300 Blackout. My Ruger American in that caliber shoots these into one hole cloverleafs at 100 yards. The 125 grain GMX out of my 308 shows a lot of promise as well. I intend to try them in other calibers.

I have not loaded any components but I have shot a couple bull elk with the 185 Superformance ammo out of my .338 Win Mag. The Superformance ammo was MOA or better for me. The velocity was a little disappointing as the average fps was 3022 from a 22.5 bbl

Wish I can get those groups

I get good groups with 139 7mm GMX handloads using RL 15 out of my 7 08. They aren't as accurate as match bullets, but they sure put down game.

I've not had much luck with GMX bullets either and I've tried them in a number of calibers, both in factory format and in handloads. I've had such poor results that I won't buy any more GMX bullets for reloading and I've even pulled a bunch of 120gr GMX 6.5 CM Superformance factory loads just to get the brass! I've had such good results with Barnes bullets that I'm not interested in trying to find a GMX load that works well. I'll buy Federal Trophy Copper if I need a good factory load that uses a copper bullet.

When I first got a 6.5 CM barrel for my AI AW I shot three 5-shot groups using Hornady's 140gr A-MAX load (12, 3 and 6 o'clock) and then shot a 5-shot group using the 120gr GMX load (9 o'clock). This is a small data set but follow up tests with the GMX stuff didn't get any better so I don't waste barrel life with it. The AI will shoot almost any factory load well, and some exceptionally well, but the GMX is not one of them.

GMX stands for "Gay Max". You have to shoot them out of a 270.

Factory Superformance 80 grain GMX works well out of my 243. About 1" groups, or maybe a little less, off a block of wood. Advertised velocity is 3400 fps, but I didn't clock it.

Good to know - just bought a box of .277 130's to try and then discovered this thread. Sounds like I needn't worry...

Be curious to see....start low, work up...

I have used the SuperPerformance GMX 150 in 30-06, as well as the 150 SST SP, and Remington's 150 Corelokts in my heavy barreled Mauser 98 for the last several years.i. The SST and GMX run 3-shot, inch groups, at 300 yards, the Corelokts just slightly larger. Federal 180s(Powershok??) do the same, tho I don't recall offhand where they print in relation to the above mentioned. It seems this rifle just isn't real picky....... . Probably shoots even NP as well....

At 300 yards the SST loads shoot about 6 inches higher and 4 inches right of the Corelokts, and the GMX about the same from the SSTs.

I have not used the SP loads in any other rifle. I have found no advantage to using GMX vs SST at over 300 yards on caribou. Inside 300 yards, they seem to do a bit less damage than SST, which can create LARGE wounds, especially if hitting bone or large muscle mass. Inside 300 yards, I see no advantage to using either of the SP loads in preference to the Corelokts.

These are all factory loads. I have not hand loaded for this rifle. Pretty sure i can't do better than that for accuracy over the factory fodder! Even if I had better eyesight.....


My experience with Barnes TSX factory loads in .260 and .243 indicates I will probably never buy another box of same in any caliber. Not when those groups are 4 moa and much cheaper Corelokts do moa in those two rifles. Outrageously priced with inferior accuracy just doesn't float my stick.

Might try some TTSX in hand loads when I get back to it. Probably not. All copper bullets (expensive!) just don't excite me much when C&C have proven to do all I require of them with less copper fouling.

Every rifle has favorite projectiles. I have one 30-06 that only shoots 220 gr. RN Sierras well. I tried several other weights and shapes with no luck. Maybe this is why some folks have luck with the GMX and others don't.

The factory Horn. Creedmoor load shots decent, sub MOA 3 shot groups in my Wife's RAP, not anything like an AMax or NP, but works

This is true. My .260 doesn't seem to like anything but 140's. Pretty much any 140.... I can live with that.

One reason it didn't like those Barnes 120 TSX, no doubt.

The only real test is to shoot and see....

The only one I've tried is the 139g .284 in a 7mm Remington Mag. I eventually found a load that would go sub-MOA for 3 shots, although it was much more work to find than the 150g Barnes TTSX. That was the easiest load work up I've ever done with that rifle. 0.5-0.75" 3 shot groups.

The GMX did seem to be a bit sensitive to seating depth. When first testing the bullet, after finding a good charge weight I tried various seating depths. My load work-up was initially done at 3.320", but I decided to test various other seating depths:
3.360" COAL -> 3.079" 3-shot group
3.330" COAL -> 1.306" 3-shot group
3.300" COAL -> 1.234" 3-shot group
3.280" COAL -> 1.318" 3-shot group (don't ask my why this wasn't tested at 3.270", it was 7 years ago. )

And later:
3.290" COAL -> 1.618" 3-shot group (not sure what happened here...)

After switching powders, later testing with more shots showed that the GMX could reliably run 1 MOA to 1.25 MOA. I won't complain about that performance for large game (in this case, Elk).

It's my backup hunting load if for some reason I run-out/misplace the 150g Barnes TTSX.

Forget that. Sounds like a another berger seating depth goat rope

Same for me. About 1" groups in my model seven, which was as good or better than anything I've tried, including several different factory offerings and several hand load combinations with 80 gr TTSX. I killed several deer with the GMX and was impressed, however I later bought a chronograph and found that these were only shooting about 3010 fps in my 20" barrel. For comparison, I'm getting 3180 with the TTSX and 1 grain under max load of RL 15 with less recoil and muzzle blast, which is important when loading for a 9 yr old.

I have never had a problem getting very good accuracy with the TSX or TTSX. From the 222 Rem to the 416 Rem with a bunch in between. And performance, well always stellar. As such, I do not play with others.

Every cartridge I have loaded with Barnes TTSX has performed well. No reason to mess with GMX or other monolithic bullets at this point. The 150 GMX shoots fine in son’s Garand for plinking. I bought a bunch of blems cheap from Midway a few years ago. Happy Trails

I guess TTSX it is

I have a model seven ks that shoots 139gmx well under an inch....consistently. I'd have to look up load recipe. It was my first try with them...same thing with 140 txs and ttsx. It's just one of those rifles that will shoot anything

I've never seen a TTSX that didn't shoot lights out with a max (or near max) charge and the bullet seated to the front of the first driving band. 243, 260, 7-08, 270, 30-06, 308, 338, 375 H&H..

In my 7X64 they have been OK, definitely something that I would hunt with. Not as accurate as others and not as high a velocity. Still well within my standards for a hunting load. About 1.5" at 100 yards for 5 rounds. About the same result with factory Barnes TTSX loads. The GMX were reloads.

I ran two boxes of factory Hornady GMX ammo through my Ruger M77 7mm-08 and killed a spike elk at a little over 100 yards with one shot (through and through, hitting bone low front shoulder). The wound channel was pretty savage, but bone chunks seem to help tear shtuff up. The accuracy at the bench was from the high .5's to low .7" with 5-shot groups. After seeing the x-rays of lead in harvested game animals, I wanted to try some monometal bullets for the health and safety of my family. Even if a cup/core bullet retains 90% of its weight, that's still 14gr of lead seasoning in my meat with a 140g bullet. No. Thanks.

My buddy just tuned-up a Savage Lightweight Hunter in .308 and has some Cutting Edge bullets in copper and in brass to try out. If they shoot well for him, I might also give them a try, but they are quite spendy when compared to factory Hornady GMX fodder, which has already earned a place on the shelf in my book.

So all grooves are seated in the neck?

Not my pic, but just like this. Maybe a hair above the neck so crap doesn't get in. Yes, I set the seater die by eye. Measure later.

Copy. I’ve gotten acceptable accuracy but never “lights out” that alotta folks get... ill have to try the 80’s in the 6 ai again...

Maybe my lights aren't as bright, but MOA or better.

Ya I had em moa in my 6, the 80 BT’s were better so I ran em and killed several big deer with em. I’ll mess with the seating a little more see how they doo.id like something to dig a little deeper for bears and bulls..

I seat 0.050" off, and they always shoot.

I never got a 3" group with them during load development (30-06, 270, 300 WSM) BUT out of the three (Barnes TTSX, Nosler eTips,Hornady GMX), they gave me the largest group. Actually it was in that order from left to right tha gave me the best to worst groups. The GMX did shoot sub-MOA Just not one ragged hole.

If you look at MCMXI image of his target on page 1. My group with the GMX looks like his 3 o'clock orange dot.

Hello I have just gotten in to reloading. Have purchased some GMX 180gr for my 300 win model 70. I am having issues with the distance they have to be into brass base of bullet seems to be quite far past the shoulder with one grove showing above neck that’s as long as I can go to run through my rifle. .134 off lands any help appreciated.

Andrew, you've landed in an old thread. You might want to check out the big game reloading forum here and pose that question there.
Welcome to the fire.

OSU_sig. Thank you

120 grain superformance shoots real well in my daughters 6.5

I get 1 inch or better groups with Hornady 139 gr. GMX in factory Full Boar ammo in my 7-mm-08. Ruger American rifle.

Mine like em best when seated .015” off the lands

Tried a box of factory GMX in a Rem 721 30.06 and was unimpressed.

Out of my rifles, the Superformance 243 80gr GMX shoots over two inches over five shots, 6.5 and 7-08 GMX group about one inch.

I have only tried their .224 70gr sample in an otherwise very accurate 1:8" 22-250 and could not get them to group any better than 1,5" at 100 meters.

My only experience is with the 250gr in my 375 Renner. Just 3 shot groups, but one (and it could be the 1st, 2nd, or 3rd shot) was always 1 1/2 - 2" out no matter the powder load, the other two always next to each other. The 250 TTSX shoots sub 1" all day. Terry

I have one rifle that shoots GMX factory ammo OK.
I have hand loaded them in several other rifles with no luck. Same story with Nosler E Tips.
I've yet to find a gun that won't shoot TSX and latter Barnes well.

I've noticed they need a bigger jump than SSTs to shoot well. I'm at 0.030" but don't be surprised if you need more.

The 185 .338 GMX has shot very well for me. TTSX (185 and 160) has shot excellent as well.

I never had much luck with them, hunting accurate but not really "tight" groups. 6.5 and 7mm.

Yep, seat em deep, they shoot well so far in my rifles.

Bumping this for a little load development I'm about to do with some 165 grain .308 cal GMXs.

Caliber: .308 Win
Propellant: Varget
Starting charge: 42.0 grains
Seating depth: .050" off the lands
Brass: Winchester
Primer: Federal 210

Sound logical for a 1:10 rifle?

The 165 Gr GMX Superformance ammo shot well out of my 300 WSM but I noticed earlier this month that Hornady has discontinued the GMX and replaced it with the new CX bullet. Unfortunately I don't see a 165 Gr Superformance load for the 300 WSM

https://www.hornady.com/bullets/cx#!/

Yeah saw that, I just have a .308 that has done well with factory GMX stuff so I want to try my hand at loading some. The additional benefit is that if I am able to successfully find a good load, you'll see me groveling in the classifieds for any 165 GMXs that anyone may have left over

Several years ago I traded for a tupperware stocked Savage 10 in 6.5 CM. For a $400 dollar rifle with a 3-9x40 scope it shot 120 grain GMX Superformance factory ammo into 1/2" 3 shot groups.

Never tried them in any other cal.