Hornady 165gr GMX question

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luckey

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Hi, anyone load this 165gr GMX bullets in 308? I am a little bit confuse with the load data listed in hornady manuals.

I have both the 9th and the newest 10th edition from Hornady. as listed, 165gr GMX and SST should be the same load data, however, the GMX bullet is lot longer than SST bullet, when loading at 44gr(the best group for SST in my rifle), I can hear the powder got compressed really hard as when I shake it, there was no sound at all. I am a little bit concern about this. Is it normal? Thanks!
 
Hornady says that you can load the gmx the same as their cup and core bullets. Being as it is a 308 I would drop down some weight for mono metal as they need speed and lots of it to open up reliably. 2000 fps is the absolute minimum with those bullets. Faster the better.

As for compressing powder there is nothing wrong with doing it. I try to have everything I load to compress at least a little bit.
 
The starting load is less than 44 grains I assume, so what were the pressure signs as you worked up? If their weren't any then a compressed load is fine.
 
I just started to test GMX bullets and was hoping to save some test bullets as hornady manual list it's the same data as sst.
I don't have problem with compressed load as that's what I got when I loaded sst to near max. However, the same load I think it's too much for gmx due to the extremely unusual long size which compress the powder too much. I can use the same data from 165 sst with 168 bthp as they are listed the same as well, but do have doubts on the gmx being listed on the same page which is why I asked here and email hornady as well
I noticed in hornady manual, for 223 55gr gmx, it's listed seperately from other 55gr bullets with less charge. Wonder if Hornady made a mistake on the 308 gmx

Worst case, I just have to work my load again from scratch
 
Thanks. Is your load near hornady max and no powder sound when you shake you loaded ammo? My 44.2gr varget is well below hodgdon's 46gr compressed load, but over hornady's max, but no pressure sign at all with sst even I can hear the bullet crunching the powder, but when shaking, there is still sound. With GMX, it's just like solid.

hometownhero said:
No mistake. I load gmx in my 7mm-08 exact same powder charge as interlock. Speed is good and no pressure signs.
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luckey said:
Thanks. Is your load near hornady max and no powder sound when you shake you loaded ammo? My 44.2gr varget is well below hodgdon's 46gr compressed load, but over hornady's max, but no pressure sign at all with sst even I can hear the bullet crunching the powder, but when shaking, there is still sound. With GMX, it's just like solid.
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Hornady doesn't have data for h4350 they have imr 4350 max at 46.7gr. I used hodgdon data that has a max of 50gr with h4350. I use 48.7gr for interlock, sst, gmx all have no pressure signs and all are very close in speeds.

As always start low and work up.
 
Thanks again. I started @41.8 and will see how it will go. With this charge, it feels like sst, while the bullet was crunching the powder, I still could hear the sound when shaking the reloded cartridge. Still curious to hear back from Hornady

hometownhero said:
Hornady doesn't have data for h4350 they have imr 4350 max at 46.7gr. I used hodgdon data that has a max of 50gr with h4350. I use 48.7gr for interlock, sst, gmx all have no pressure signs and all are very close in speeds.

As always start low and work up.
Click to expand...
 
yes. agreed, but as I mentioned in the earlier post, while I am NOT worried about the 'regular' compressed load(bullet crunching the powder, but I still could hear the powder moving when shaking the cartridge), when loading 165 GMX to 44gr with 2.75 OAL as listed in hornady manual, the compression seems to be a little excessive as when I shook the cartridge, I couldn't hear anything at all. Is that normal for max compressed load?

hometownhero said:
Compressed loads are nothing to be worried about they can also deliver more consistent performance.
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luckey said:
yes. agreed, but as I mentioned in the earlier post, while I am NOT worried about the 'regular' compressed load(bullet crunching the powder, but I still could hear the powder moving when shaking the cartridge), when loading 165 GMX to 44gr with 2.75 OAL as listed in hornady manual, the compression seems to be a little excessive as when I shook the cartridge, I couldn't hear anything at all. Is that normal for max compressed load?
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Yes.Did you just load 44gr or did you work up to it? You changed the bullet so I hope that you worked up to it again and didn't just load them at 44.
 
Yes, I am starting back down from 41.8gr and also will chrono it to get an idea where I am at, but would also like to confirm here before I go to shoot on weekend. not that suicidal. :p

hometownhero said:
Yes.Did you just load 44gr or did you work up to it? You changed the bullet so I hope that you worked up to it again and didn't just load them at 44.
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