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View Full Version : H335 with (J-word) Hornaday 123gr SST( 7.62x39)



Animal
06-07-2014, 04:19 PM
Hey folks,

I picked up some H335 today because I thought I had some good load data for it with the 123gr sst bullet. It turns out, I have data for the 123gr Soft Point with this powder but not the SST. I meant to base this load of of Lymans 49th edition, but now I have some issues with compatibility. Both the SST and the SP have a similar profile, but the SST is a significant bit longer.

Now, I'm loading these rounds as long as will feed in my magazine, which comes out to about 2.242. Yet, at this length I make up for some of the case capacity that is lost with this longer bullet, but it doesn't provide me with enough relief to use the data listed for the SP bullet. The powder fills the case up and creates a compressed charge at 30.5 grains (which is the starting load for the 123gr SP). I understand that the max end of this powder charge should be compressed if using Lymans data.

Lee does not list data for H335 for a 123gr jacketed bullet, but does for a 125gr.

Hodgdon skips right over the 123gr bullets and goes to 125gr just like Lee.

Hornaday doesn't mind mixing a 123gr with H335, but it only list the SP which is a good bit shorter than the SST.

I filled a case with 27gr of H335, sunk a bullet at 2.240 and could hear powder sloshing back and forth while shaking the round next to my ear. I then charged a case to 28gr, sunk a bullet to the same depth, and I was unable to hear the sloshing--leading me to believe 28gr is where the load becomes compressed.

Going off of the understanding that we are compressing the load for a max charge, I'm guessing that 28.0gr would be MAX at this this seating depth, leading me to believe that starting around 25.0 would be an appropriate MIN starting point.

I'd like to hear from some experienced folks before I proceed with this load. My logic might be a bit flawed. Thanks folks.

petroid
06-07-2014, 10:55 PM
My copy of Hornady's 9th doesn't list H335 with 7.62x39. Hodgdon lists a max of 31.5 with a 125gr bullet at 2.15" and a max of 29 with a 150 gr bullet at 2.2". I would think that the SST wouldn't seat as deeply as a 150gr bullet and you are seating out a tad longer than they are. You should be fine to start at 26 but 25 may be safer. Is this a .310 bullet? I ask because Hornady lists a .312 SST in their manual but it isn't a catalogued item. I have some .312 150gr SSTs for my Mosin Nagants and I believe they are made specifically for Graf's by Hornady. But I also have the .310s

Animal
06-08-2014, 08:26 AM
You are right. My Hornaday doesn't list H335 for the 7.62x39. I have all my manuals out and some of the data seems to be running together.

Yes, this is a .310 bullet. Thanks for your input on a good starting point. I slugged my barrel a few weeks ago and found that my groove dia. is pretty close to .313, so I have some of the .312 150 grainers on the way from Grafs too. However, I was hoping to get good accuracy from the 123 sst so that my point of impact would be fairly close to my cheap Rusky ammo.

When the .312 150gr show up on my door step, I'll be using Hogdons data.