Home Forums Hunting & Shooting Predators and Varmints .243 90 grain GMX on Coyotes

Would anyone have actual experience using the .243 90 grain GMX on coyotes? I would be running them at 3350 fps muzzle velocity and trying to get a good dual-purpose deer and dog bullet. Currently I'm using 90 grain Scirocco's which expands and blows a nice big exit hole on coyotes but want a different bullet for deer. Just wondering whether the GMX would expand enough or just punch a .243 diameter hole in a coyote. Thanks.

It will expand as much as it is going to in the first couple bullet lengths. Would be great on deer and hogs, you might get some runners with coyotes due to very little energy transfer, though your speed may help with that.

Do you have to shoot a non leaded bullet by law?

Your working at this to hard, 100 gr. SGK will solve both problems, it's just not as sexy a GMX, and it's 1/2 the price. Rio7

No...the reason I'm thinking of the GMX is because of the high velocity 3350 fps at the muzzle. At close shots at deer I want a bullet that will smash through both shoulders, yet have a reasonable b.c. for the 350 yard shots (less wind drift and less drop).





I use the 90 grain Sierra Tipped Game King in another rifle at 3120 fps and it's been superb so far. I doubt if the 90 TGK will hold up at 3350 fps. I have some 100 gn SGK and they clock 3200 fps, but surprisingly don't group as tight as the 90 grain Swift Scirocco's. My second choice if the 90 grain GMX doesn't work on dogs too well is the 100 grain Sierra Tipped GameKing which has a b.c. of .515. But I would prefer a stout 90 grain for the very flat short to medium range trajectory. My barrel has a 9 twist, and I would need an 8 twist for the GMX and 100 grain TGK. That is why I'm asking about the 90 grain GMX on dogs...I'd rather have a good idea that they will work ok on dogs before I re-barrel.

90 grain Accubond or Ballistic Tip.

Bet that 90 grain tipped GK is just fine, maybe too tough for coyotes according to Sierra claiming they are harder than BTSP Gamekings.

It would be good if they are ok as they have a very good b.c. of .490 and I already use them in another gun as my preferred projectile. My rifle has a very long throat and to seat close to the lands means that there is not much neck holding the projectile because of the aggressive boat-tail on the 90g TGK. The best accuracy in my other rifle is seating at .001" from the lands (virtually touching the lands). If they are as forgiving as the 140 grain .270 TGK with seating depth, and are accurate with more jump to the lands they may work. With a 90 grain all gilding metal or copper projectile, they will be longer and allow more grip by the neck and often they do well at say .050" from the lands. Another thing, they often have 100% weight retention so they perform like a 100 grain projectile that sheds some of its weight....yet shoots flatter at short to medium range because of the 150 fps speed advantage. The b.c. on the GMX is .424, on the Scirocco it's .419 - I don't want any lower than on the Scirocco.

This......

If your going to shoot coyote with a 243 your going to get a large exit period.....don't care what bullets you shoot.....use the best bullet for deer....who really cares if you punch a large or small hole in them.....

Are you using the Scirocco or Scirocco II?

Scirocco II


I'm thinking the best bullet for deer at 3350 fps through the shoulder at close range and at around 350 yards will be the 90 GMX. Hence my original post asking if anyone has ever actually used the 90 grain GMX on coyotes and got some expansion?

Good luck in your search.

Quite a few bullets that will do what you're wanting but if you're locked in on the 90 grain GMX then give it a whirl.

Worst thing is possible minimal expansion on a coyote, I have no issues w that.

I have not used the GMX, but have killed a few dozen coyotes with the 80gr TTSX and 85gr TSX.

They have been very effective, no runners or spinners, pelt damage has been very minimal.

I suspect the GMX will perform quite like a Barnes.

thanks for that information

I have double dutied bullets for both coyotes and deer but quit. Why not have a faster and flatter shooting load for Coyotes and a bullet just right for the conditions you hunt deer in? Is it so hard to sight in a new load. My dual purpose loads generally cover feral hogs and coyotes. The hundred grain Partiton out of my 260 Remington is perfect. Having I would say easily a dozen deer rifles I just don't see the need to "double duty" anything as far as deer go. That would mean only having one rifle when you could have two. Lacks logic completely.

You might be after deer and see a coyote and then you're not going to have time to change ammo and resight your scope. Why constantly change loads and resight your rifle just because you're shooting something different? Makes sense to just have one load per rifle.

I take deer hunting seriously and unless I am getting ready to go home will not involve myself in gunfire on the lease not directed toward a deer during deer season. Hence I would just shoot the coyote with a deer load and then only if I was on the road headed out of the lease on the way home. I take my 10-20 coyotes after deer season. I take that job seriously also.

You don't save any money by switching loads, as the cost of re-sighting your rifle each time you switch loads outweighs the additional cost of the expensive bullet with just one load. A 90 grain 6mm at 3350 fps with a decent b.c. is plenty flat enough for coyotes. I travel with my rifle, sometimes get on a plane..just take one rifle. If I'm away for a week and fill out my deer tag early, then I go after something else rather than sit around camp.

Same here, 1 bullet in my 6mm for deer or coyotes.

Been the 95 grain Partition lately but may try the 90 grain Ballistic Tip.

Plenty of bullet to punch through deer and flat enough for me to max ranges around here.

Dad used the 85 grain Sierra SP in my 6mm for the late 70s and I used it until 5sh years ago when I just wanted to try something different.

I would have no issues getting back to that for a combo bullet. Works well at powder burn ranges to that 440+ yard fence line that is so common around here.

The 90 grain sierra TGK will bust bone fine. I've been using them in my 243 AI and punched a buck in the neck that was walking to me. He was maybe 40 yards. It went through his rutted up neck, took a couple vertebrae, the top of a shoulder blade and broke a couple ribs before it stopped.