Hornady has just come out with a new GMX bullet for the .223 that I'm excited to use in my AR for deer. I contacted Hornady last week for some details and this is the information I got. I can't seem to find a retailer that carries them, however.


"The bullet is the same profile as the 75 gr BTHP. When I tested this bullet, I used the same load info as the 75 AMAX & 75 gr BTHP bullets. This is definitely one that a person wants to start low and work his way up in charge weight. COL is 2.250 the same as the 75 BTHP. ... The BC on this bullet is about a .365. I would say your going to be about .5 grs lower charge weights than the 75 BTHP data. "

Slim, I'm definitely not against using such a light caliber or the use of the AR but I do have concerns about the terminal performance level you'll achieve with such a heavy bullet and short barrel !!!

Did Hornady give you a operating range for expansion on the bullet ???
What are you expecting in the way of velocity ???
Will this set up exceed any self imposed limitations ???


I'm not trying to be argumentative just starting a discussion on the issue !!!

I would have no worries about terminal performance.

How do you know he's using a short barrel?

Grumulkin wrote:

How do you know he's using a short barrel?

All good questions.

Most ARs have short barrels but the one I'm planning to use is a 24" 1:8 twist.

The GMX bullets typcially need 1900 to 2000 fps to open up.
I expect a muzzle velocity of 3000 fps.
Most of my deer shots are 120 yds or less. I haven't set a personal limit until I figure out my performance.

The GMX bullets in my .270 Win are the most accurate of any I have tried. If they do as well in my AR, I will have a real tack driver.

chambered221 wrote:

Slim, I simply believe 85-100gr bullets traveling 3,000fps are more than adequate to create an instantaneous humane kill. I have witnessed this on several occasions over the years and have seen the damage with my own eyes.

this was your comment from the 250 AI topic. 70 gr is getting pretty close to 85 and the deer in Texas are not as big as up North.

slimjim wrote:

...and the deer in Texas are not as big as up North.

That is a fact - A buddy of mine sent me a picture of his north Texas deer kill and I asked him if it was still chained to the dog house when he shot it...

Shot placement trumps all considerations of light small caliber bullets. the WOA AR Slim uses should put it within the pumper out to 500 yards so a 120 yard shot he could pick the hair he wants to hit on the hide.

You will not get away with a marginal shot from a .22 that you might get with a 165 grain .30 cal. It is not for everyone and using smaller caliber for larger game should be entered into with some thought, like Slim is doing. Kinda like using a .243 on Elk...

good call Dawgdad in the neck or the boiler room or not at all with the smaller calibres. there has been a heck of alot of red deer shot with the .222 ,.223 in this country in the hands of a good shot within a responsible range they are deadly but take the wrong option and you will have a hard time tracking the animal down. the smaller blood trail is the other consideration. sawing all that I take my .223 for walkies in the forest too I havent shot a deer with it yet but thats only cause the chance hasnt been there YET... 6 pigs have gone straight down from single hits with it so I have faith in my ability with it which is really what matters at the end of the day. if you think its ok well then its ok.

I really am of two minds about using smaller calibres on deer. I have a mate who insists that his .223 is more than adequate on deer, yet I have seen two deer he shot require a second shot to actually put the animal down...and these were Fallow deer. One was at about 150 metres and the other at about 200 - 230 metres. He was using 62gn bullets (can't remember the brand), but they seemed to lack the oomph required to do the job.

I am a firm believer in overkill...use enough calibre to do the job, then add a good solid "fudge factor" to make sure.

I don't doubt that you can put your shot exactly where it needs to be Slim...but think about not just the round being used, but also it's ability to deliver a good, humane, clean kill mate...we owe that to the animal.

Cheers, Vince

I think bullet construction becomes critical in the smaller calibers used on larger game. The monolithic bullets that have near-100% weight retention for deep penetration provide the discrimator to consider this caliber optoin. That is why I am interested in this bullet. I'll get some pictures of different .223 bullets for comparison and list my loading results.

Grumulkin wrote:

I would have no worries about terminal performance. How do you know he's using a short barrel?

I do, that's why proposed the scenario for discussion!!!

Don't/didn't

Slim, I think you'd agree that a 85gr. bullet traveling 3,000fps isn't a long range killing machine !!!

Quote::

I think bullet construction becomes critical in the smaller calibers used on larger game

It does !!! I've had this discussion with Nosler in the past. It's one of the reasons I prefer .25cal and larger for deer.

In my experience, a larger bullet doesn't do any good if shot placement is not in the vitals. I've learned not to take heart shots because it is too small a target and I didn't know where the heart really was because I could not actually see it - only imaging it. Off just a bit on a heart shot and I'm tracking deer into the thickets hoping I can recover it - .243, .270, .308 it didn't matter. If the bullet is in the vitals - that is the where the discussion has gone.

BTW, I cringed when a hunting friend told me that he uses 55gr FMJs in his AR to hunt deer. He uses neck shots and was more successful last season than me. Another does head shots. I just can't get myself to take neck and head shots.

Best advice I have ever received is:
Know your rifle but
Know yourself better

A dipstick with a 300 WM who shoots "at" an animal hoping to hit it and thinking his cannon will do the rest of the job for him is worse than a poacher in my book. Neck and head shots are for expert riflemen/women who know when to pull the trigger and when to pass up the shot and put one in the vitals. After finding a moose all but dead in tall grass with its lower jaw shot away I decided to never take the chance myself because I know my own skill level with a rifle.

A poorly placed shot is a poorly placed shot regardless of bullet size period !!!

Great advise Mac !!!
I've shot deer in the head and neck when the opputunity has presented itself......... probably would have shot more that way if I could carry a bench to the woods !!!

A few of those were with 55gr B-Tips leaving the muzzle over 4100fps ............

the chamious or shammy as we call them have been known to absorb a heck of alot of large hucks of magnum lead if the first shot is not right and the adrealin kicks in look out. the big advantage of a larger/heavier bullet is the bigger out hole to let the red stuff out, makes it easier to track if the shot isnt quite right. the smaller/lighter/softer projectiles wont exit to leave blood trail. those barnes type projectiles look like they will get around this.