Hornady CX vs GMX update

[Adyb]

I have been reluctantly trying out hornady CX 150gr 7mmRm due to dire non lead shortage in France (factory ammo, Outfitter branded). Results have been pretty good, groups good on paper and kills include a 25kg chamois at 350m - shoulder shot through thin part of blade but still in body cavity below spine. Passed right through, liquified lungs, dropped dead on spot. I didn't recover bullet but plenty of shock evidence (yes had some bone to aid expansion but still good for a small animal at that range).
Also knocked over a couple of reds at shorter distances incl a stag with a low heart shot at 70m which took 2 steps then rolled over.
Go to copper ammo previously has been Barnes TTSX - not ready to compare yet, seems less meat damage for equivalent shots, prob a bit smaller exit but seems to mess up internals well - so expanding where it needs to.

Only got through one box (half shot at paper) so early days but enough to convince me hornady have made a good step fwd from GMX.

Felt obliged to share this coz I've talked about bad gmx performance in the past and suggested 'CX' might just be rebranding.

 

[User00040]

@Adyb

Have you tried using the Hornady 4DOF app for ballistic modelling and compared real world drops?

 

[Adyb]

@Adyb

Have you tried using the Hornady 4DOF app for ballistic modelling and compared real world drops?

Started playing with it but not properly yet.. will update if i get any meaningful conclusions. I'm shooting at quite high altitudes so need to take care with data. Also can't see much difference between what im getting from strelock pro and 4dof so far
Got good correlation between strelock and real drop pretty quickly using hornady data for the round. Shooting a tiny bit flatter than predicted for same length of barrel

 

[hendrix's rifle]

Maybe the tip they changed did have more effect than everyone realised

 

[Adyb]

Maybe the tip they changed did have more effect than everyone realised

I think the changes in grooves have helped expansion on impact and maybe the mushroom shape is better. Stuff about better polymer tip for longer ranges also seems to have a bit of merit. The problems I've had with copper monos in the past (specifically trophy copper and GMX) has been pencilling through body cavity when bone not encountered on impact, lack of shock results in the animal running - all my kills so far with CX have hit at least some bone on the way in and evidently expanded well. Not yet seen they can do the same job as ttsx on a softer entry scenario but lets see (I don't trust the you tube gel block vids!)

 

[Heym SR20]

I think the changes in grooves have helped expansion on impact and maybe the mushroom shape is better. Stuff about better polymer tip for longer ranges also seems to have a bit of merit. The problems I've had with copper monos in the past (specifically trophy copper and GMX) has been pencilling through body cavity when bone not encountered on impact, lack of shock results in the animal running - all my kills so far with CX have hit at least some bone on the way in and evidently expanded well. Not yet seen they can do the same job as ttsx on a softer entry scenario but lets see (I don't trust the you tube gel block vids!)

I had similar with the GMX - it was too tough for smaller deer and other European animals. Probably OK for large North American and African game.

Clearly the CX works well and you are confident enough with it to take a nice Chamois at 350 metres. Nice shooting

 

[User00033]

The design of the bullet especially the relationship between the ogive and the size and profile of the hollow point is likely to have a significant effect on the yield point....the amount of energy required to deform the bullet into either expanded petals or breakaway shards.

This is exactly the research and development Richard's been doing with his excellent Yew Tree bullets.

In his case, certainly not "classic marketing' but trying to find the best balance of the parameters, to produce a better bullet.

From another thread.

This made a lot of sense to me and explains why expansion testing of the CX has looked very positive compared to the old GMX.

I only know one person here who has tried them so far and his feedback was unanimously positive.

 

[samdk]

@Adyb

Have you tried using the Hornady 4DOF app for ballistic modelling and compared real world drops?

I have done a test with my 6cm against StrelokPro and 4DOF looks promising!

If you use one of the drag curves it seems shoots where it should without the need to “validate/true” the BC provided you get the velocity (and temp this was taken at) , temp and air pressure.
StrelokPro’s truing process is essentially bullshiting data to make things match and usually has a knock on effect elsewhere.

Hornady just need to add drag curves for more bullet types from over manufacturers.

 

[ChrisA]

So to add to the discussion, I shot a Red Stag this morning using a .270 Hornady CX 130grain. I was watching a stag chase 6 hinds across an L-shaped field at around 350-300 yards, so I got setup on the bipod for a longer shot, rather than my sticks and the hinds stopped around 250 yards, he was running and couldn’t get a shot due to maze stubble being slightly too high. The stag then left the hinds and ran off around the corner of the field out of sight, I didn’t want to move in case the hinds spotted me and I though he might come back to them. I could see the hinds watching him and I then rearlised he was coming my way. He ran down the side of a headland through some long knettles and thistle, straight towards me.I quickly wound the scope right out and pulled the trigger at 13 yards! The stag dropped dead instantly, having shot him in the front and I aimed for his neck and the shot passed though it’s body cavity ended up near his bladder! Luckily no guts were split and he has so much internal fat below his spine it was a clean kill with no meat damage.
It was interesting to see that the CX bullet had very little expansion, given the close range.

 

[hendrix's rifle]

So to add to the discussion, I shot a Red Stag this morning using a .270 Hornady CX 130grain. I was watching a stag chase 6 hinds across an L-shaped field at around 350-300 yards, so I got setup on the bipod for a longer shot, rather than my sticks and the hinds stopped around 250 yards, he was running and couldn’t get a shot due to maze stubble being slightly too high. The stag then left the hinds and ran off around the corner of the field out of sight, I didn’t want to move in case the hinds spotted me and I though he might come back to them. I could see the hinds watching him and I then rearlised he was coming my way. He ran down the side of a headland through some long knettles and thistle, straight towards me.I quickly wound the scope right out and pulled the trigger at 13 yards! The stag dropped dead instantly, having shot him in the front and I aimed for his neck and the shot passed though it’s body cavity ended up near his bladder! Luckily no guts were split and he has so much internal fat below his spine it was a clean kill with no meat damage.
It was interesting to see that the CX bullet had very little expansion, given the close range.

It looks more like the petals have separated and left the 'core' which has started to expand given the rifling in the bullet. It looks like an intact one would be substantially longer?

 

[Acm]

It looks more like the petals have separated and left the 'core' which has started to expand given the rifling in the bullet. It looks like an intact one would be substantially longer?

My thoughts too, looks like the petals have broken off which would definitely be expected on that game at that range. Suspect impact velocity would be in the region of 3100 fps, straight into bone. That’s hard on a bullet. I’d say that’s done rather well.

 

[Adyb]

My take too, anyway im going to give them another go this chammy season. Can't get lrx for love or money round here

 

[davegixxer]

Hi quite new to this reloading but I cannot find load data for 150 cx in either the 11th edition or the on line app are people using the data for 150 gmx? Thank you any help appreciated